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Theories of tumors. Do you know modern theories about the origin of cancer? Theory of physical carcinogens

1. Property of the tumor

A tumor (other names: neoplasm, neoplasm, blastoma) is a pathological formation that independently develops in organs and tissues, characterized by autonomous growth, polymorphism and cell atypia.

A tumor is a pathological formation that independently develops in organs and tissues, characterized by independent growth, diversity and unusualness of cells.

A tumor in the intestine (folds are visible) may look like an ulcer (shown by arrows).

Properties of tumors (3):

1. autonomy (independence from the body): a tumor occurs when 1 or more cells go beyond the control of the body and begin to rapidly divide. At the same time, neither the nervous, nor the endocrine (endocrine glands), nor the immune system (leukocytes) can cope with them.

The process of cells leaving the body’s control is called “tumor transformation.”

2. polymorphism (diversity) of cells: the tumor structure may contain cells of heterogeneous structure.

3. atypia (unusuality) of cells: tumor cells differ in appearance from the cells of the tissue in which the tumor developed. If a tumor grows quickly, it mainly consists of unspecialized cells (sometimes with very rapid growth it is even impossible to determine the source tissue of the tumor growth). If slowly, its cells become similar to normal ones and can perform some of their functions.


2. Theories of tumor occurrence

It is well known: the more theories are invented, the less clarity there is in anything. The theories described below explain only individual stages of tumor formation, but do not provide a holistic scheme for their occurrence (oncogenesis). Here I present the most understandable theories:

· irritation theory: frequent tissue trauma accelerates cell division processes (cells are forced to divide in order for the wound to heal) and can cause tumor growth. It is known that moles, which are often subjected to friction by clothing, damage from shaving, etc., can eventually turn into malignant tumors (scientifically, they become malignant; from the English malign - evil, unkind).

· viral theory: viruses invade cells, disrupt the regulation of cell division, which can result in tumor transformation. Such viruses are called oncoviruses: T-cell leukemia virus (leads to leukemia), Epstein-Barr virus (causes Burkitt lymphoma), papillomaviruses, etc.

Burkitt's lymphoma caused by the Epstein-Barr virus.

Lymphoma is a local tumor of lymphoid tissue. Lymphoid tissue is a type of hematopoietic tissue. Compare with leukemia, which originates from any hematopoietic tissue, but does not have a clear localization (develops in the blood).

· mutation theory: carcinogens (i.e. factors that cause cancer) lead to mutations in the genetic apparatus of cells. Cells begin to divide randomly. Factors that cause cell mutations are called mutagens.

· immunological theory: even in a healthy body, single cell mutations and their tumor transformation constantly occur. But normally, the immune system quickly destroys the “wrong” cells. If the immune system is impaired, then one or more tumor cells are not destroyed and become a source of tumor development.

There are other theories that deserve attention, but I will write about them separately in my blog.

Modern views on the occurrence of tumors.

For tumors to occur, the following must be present:

· internal reasons:

1. genetic predisposition

2. a certain state of the immune system.

· external factors (they are called carcinogens, from the Latin cancer - cancer):

1. mechanical carcinogens: frequent tissue trauma followed by regeneration (restoration).

2. physical carcinogens: ionizing radiation (leukemia, bone tumors, thyroid gland), ultraviolet radiation (skin cancer). Published data show that each sunburn of the skin significantly increases the risk of developing a very malignant tumor - melanoma in the future.

3. chemical carcinogens: exposure to chemicals throughout the body or only in a specific location. Benzopyrene, benzidine, components of tobacco smoke and many other substances have oncogenic properties. Examples: lung cancer from smoking, pleural mesothelioma from working with asbestos.

4. biological carcinogens: in addition to the viruses already mentioned, bacteria have carcinogenic properties: for example, prolonged inflammation and ulceration of the gastric mucosa due to Helicobacter pylori infection can result in malignancy.


3. Mutation theory

Currently, the generally accepted concept is that cancer is a genetic disease based on changes in the cell's genome. In the vast majority of cases, malignant neoplasms develop from a single tumor cell, that is, they are of monoclonal origin. Based on the mutation theory, cancer occurs due to the accumulation of mutations in specific areas of cellular DNA, leading to the formation of defective proteins.

Major milestones in the development of the mutation theory of carcinogenesis:

· 1914 - German biologist Theodor Boveri suggested that abnormalities in chromosomes could lead to cancer.

· 1927 - Hermann Muller discovered that ionizing radiation causes mutations.

· 1951 - Müller proposed a theory according to which mutations are responsible for the malignant transformation of cells.

· 1971 - Alfred Knudson explained the differences in the incidence of hereditary and non-hereditary forms of retinal cancer (retinoblastoma) by the fact that for a mutation in the RB gene to occur, both of its alleles must be affected, and one of the mutations must be inherited.

· in the early 1980s, the transfer of a transformed phenotype using DNA from malignant cells (spontaneously and chemically transformed) and tumors to normal ones was shown. In fact, this is the first direct evidence that the hallmarks of transformation are encoded in DNA.

· 1986 - Robert Weinberg first identified a tumor suppressor gene.

· 1990 - Bert Vogelstein and Eric Faron published a map of sequential mutations associated with colorectal cancer. One of the achievements of molecular medicine in the 90s. provided evidence that cancer is a genetic multifactorial disease.

· 2003 - The number of identified genes associated with cancer exceeded 100 and continues to grow rapidly.


But... And then Zilber spoke about something that could not help but cause deep and wary silence in the hall: “... It is necessary to dwell on the successes in the field of studying the etiology of some malignant tumors. I perfectly understand the need for extreme restraint and deep caution in this complex and important issue. However, it is impossible to ignore the most recent work in...

Age. Such formations include dermoid and branchiogenic cysts. Malignant kidney tumors can develop as a result of kidney malformations (K.A. Moskacheva), etc. The clinical course of many tumors in children has its own characteristics; for example, a hemangioma, being benign in its histological structure, at the same time, in its rapid and infiltrating growth, resembles...

First they enter the regional lymph nodes, where their spread can be temporarily stopped as a result of the immune response; during surgical treatment, the regional lymph nodes are also removed with the tumor, which prevents the development of early metastases. Hematogenous metastases. The entry of tumor cells into the bloodstream is believed to occur early in the development of many...

Antigens of viral tumors; 2) antigens of tumors caused by carcinogens; 3) transplantation-type isoantigens; 4) embryonic antigens; 5) heteroorgan antigens. In undifferentiated malignant tumors, antigenic simplification occurs, which, like the appearance of embryonic antigens, is a reflection of cataplasia of the tumor cell. Identification of typical and atypical...

Tumor, neoplasm, blastoma(from the Greek blasto - sprout) - a pathological process characterized by uncontrolled proliferation (growth) of cells; in this case, disturbances in cell growth and differentiation are caused by changes in their genetic apparatus.

Morphogenesis of tumors: theories - spasmodic And staged transformation.

The theory of spasmodic transformation: according to this theory, a tumor can develop without previous tissue changes.

Stages of morphogenesis of malignant tumors:

Pre-tumor stage - hyperplasia and pre-tumor dysplasia;

- stage of non-invasive tumor (cancer in situ);

Stage of invasive tumor growth;

Stage of metastasis.

There are benign tumors that can transform into malignant ones (adenomatous polyps, adenomas and papillomas, in which foci of malignancy develop), and there are benign tumors that never transform into malignant ones.

Precancerous dysplasia. The development of tumors is preceded by pre-tumor processes. Pre-tumor processes include dysplastic processes, which are characterized by the development of changes in parenchymal and stromal elements. The main morphological criteria are considered appearance of signs of cellular atypia in the parenchyma of an organ with intact tissue structure. With epithelial dysplasia, polymorphic epithelial cells with hyperchromic nuclei and mitotic figures are found, the basement membrane thickens, and lymphoid infiltrates appear.

Stage of non-invasive tumor. The progression of dysplasia is associated with additional influences leading to genetic rearrangements and malignant transformation. As a result, a malignant cell appears, which divides, forming a node (clone) of similar cells, feeding due to the diffusion of nutrients from the tissue fluid of adjacent normal tissues and not growing into them. At this stage, the tumor node does not yet have its own vessels. In the case of cancer, the stage of tumor growth “in itself” without destruction of the basement membrane and without the formation of stroma and blood vessels is called the stage of cancer in situ, and is separated into an independent morphogenetic stage. The duration of this stage can reach 10 years or more.

Invasive tumor stage. Characterized by the appearance infiltrating growth. A vascular network appears in the tumor (if the vessel is less than 3 mm, then the tumor does not grow), stroma, and there are no boundaries with adjacent non-tumor tissue due to the growth of tumor cells into it. Tumor invasion occurs in three phases:

1) The first phase of tumor invasion is characterized weakening of contacts between cells, decrease in the number of intercellular contacts, decrease in the concentration of some adhesion molecules.

2) In the second phase the tumor cell secretes proteolytic enzymes and their activators, which ensure the degradation of the extracellular matrix, thereby clearing the path for tumor invasion. In the same time

3) In the third phase of invasion tumor cells migrate to the degradation zone and then the process repeats again.

Stage of metastasis. Spread of tumor cells from the primary tumor to other organs via lymphatic, blood vessels, perineural, implantation.

HISTOGENESIS OF TUMORS

The process of tumor development under the influence of carcinogenic factors is called carcinogenesis. Etiological factors that can cause the development of tumors are called carcinogenic factors (carcinogens).

There are 3 main groups of carcinogenic agents: chemical, physical (radiation) and viral. 80-90 % malignant tumors are the result of adverse environmental influences.

Chemical carcinogenesis occurs in several stages: initiation, promotion and tumor progression. IN initiation stage the genotoxic carcinogen interacts with the cell genome, which causes its restructuring. The cell becomes malignant and begins to divide uncontrollably. The substance that determines the beginning of the promotion stage is called a promoter (carcinogens must act on nuclear DNA and cause its damage). About tumor progression they say in the presence of uncontrolled tumor growth.

Malignant tumors are built from partially or completely undifferentiated cells, grow quickly, infiltrate surrounding tissues (infiltrating growth) and tissue structures (invasive growth), and can recur and metastasize. Malignant tumors of the epithelium are called cancer, or carcinoma, from derivatives of mesenchymal tissue - sarcomas.

The main properties of tumors are autonomous growth, the presence of atypia, the ability to progress and metastasis.

    Only proliferating somatic cells (poly- or unipotent cells) can undergo transformation.

    A tumor cell is capable of repeating in a distorted form the signs of differentiation inherent in the precursor cell from which it arose.

3. Differentiation of tumor cells depends on the level of malignancy of the precursor cell and on the level of differentiation block. Benign tumors develop during the transformation of unipotent precursor cells with a low differentiation block, so they are built from mature cellular elements. Malignant tumors are characterized by a lower level of differentiation of their cells, which is associated with their development from pluripotent precursor cells and the presence of a high differentiation block. The higher the level of malignancy and the level of differentiation block, the less differentiated the resulting malignant tumor.

"Can be used as histo- and cytogenetic markers of tumor cells" tumor markers"(growth factors, receptors, oncoproteins, adhesion molecules, enzymes, receptors and adhesion molecules).

Dysplasia is a disorder of proliferation and differentiation of the epithelium with the development cellular atypia(various size and shape of cells, increase in nuclear size, increase in the number of mitoses and their atypia) and violation of histoarchitecture(loss of polarity of the epithelium, its histo- and organ-specificity).

There are 3 degrees of dysplasia: light, moderate and heavy(characterize a precancerous condition). Severe dysplasia is difficult to distinguish from carcinomain situ("cancer is in place").

Morphological atypia(atypical tumor structure) is expressed in the fact that tumor tissue does not replicate the structure of similar mature tissue, and tumor cells may not resemble mature cells of the same origin.

Morphological atypia is represented by 2 options: tissue and cellular.

Tissue atypism: - expressed in a change in the ratio between the parenchyma and tumor stroma, often with a predominance of parenchyma;

Changes in the size and shape of tissue structures with the appearance of ugly tissue formations of various sizes.

Cellular atypism: - polymorphism of cells appears (in shape and size), - enlargement of nuclei in cells, which often have jagged contours, - increase in the nuclear-cytoplasmic ratio in favor of the nucleus, the appearance of large nucleoli. As a result of pathological mitoses, tumor cells exhibit cells with hyperchromic nuclei, giant nuclei, multinucleated cells and pathological mitotic figures.

58 THE CONCEPT OF TUMOR PROGRESSION. THE IMMUNE RESPONSE OF THE ORGANISM TO A TUMOR. THE IMPORTANCE OF BIOPSY IN ONCOLOGY. In 1969, L. Foulds, based on experimental oncology data, created a theory of tumor progression. According to this theory, a tumor is considered as a formation that continuously progresses through qualitatively different stages, by which are meant inherited changes of an irreversible nature of one or more clearly manifested signs. The acquisition of tumor properties occurs in stages, as a result of the replacement of one population of cells by another, through the selection of cell clones or mutation of tumor cells. This creates the basis for increasing cell autonomy and maximum adaptability to the environment.

Both forms of immune response arise to antigens of tumor cells (tumor antigens): humoral with the appearance of antibodies and cellular with the accumulation of killer T-lymphocytes sensitized against tumor cells. Antitumor antibodies not only protect the body from a tumor, but can also promote its progression, having an enhancement effect. Lymphocytes and macrophages, when in contact with tumor cells, can have a cytolytic or cytotoxic effect on them. In addition, macrophages and neutrophils are capable of causing a cytostatic effect, as a result of which DNA synthesis and mitotic activity in tumor cells are reduced. Thus, antitumor immune defense is similar to transplantation immunity.

"

1. Property of the tumor

A tumor (other names: neoplasm, neoplasm, blastoma) is a pathological formation that independently develops in organs and tissues, characterized by autonomous growth, polymorphism and cell atypia.

A tumor is a pathological formation that independently develops in organs and tissues, characterized by independent growth, diversity and unusualness of cells.

A tumor in the intestine (folds are visible) may look like an ulcer (shown by arrows).

Properties of tumors (3):

1. autonomy(independent of the body): a tumor occurs when 1 or more cells escape the control of the body and begin to rapidly divide. At the same time, neither the nervous, nor the endocrine (endocrine glands), nor the immune system (leukocytes) can cope with them.

The process of cells leaving the body’s control is called “ tumor transformation».

2. polymorphism(diversity) of cells: the structure of the tumor may contain cells of heterogeneous structure.

3. atypia(unusuality) of cells: tumor cells differ in appearance from the cells of the tissue in which the tumor developed. If a tumor grows quickly, it mainly consists of unspecialized cells (sometimes with very rapid growth it is even impossible to determine the source tissue of the tumor growth). If slowly, its cells become similar to normal ones and can perform some of their functions.

2. Theories of tumor occurrence

It is well known: the more theories are invented, the less clarity there is in anything. The theories described below explain only individual stages of tumor formation, but do not provide a holistic diagram of their occurrence (oncogenesis). Here I give the most understandable theories:

· irritation theory: Frequent tissue trauma accelerates cell division processes (cells are forced to divide in order for the wound to heal) and can cause tumor growth. It is known that moles, which are often subjected to friction by clothing, damage from shaving, etc., can eventually turn into malignant tumors (scientifically - become malignant; from English malign- evil, unkind).

· virus theory: viruses invade cells, disrupt the regulation of cell division, which can result in tumor transformation. Such viruses are called oncoviruses: T-cell leukemia virus (leads to leukemia), Epstein-Barr virus (causes Burkitt lymphoma), papillomaviruses, etc.

Burkitt's lymphoma caused by the Epstein-Barr virus.

Lymphoma- This is a local tumor of lymphoid tissue. Lymphoid tissue is a type of hematopoietic tissue. Compare with leukemia, which originate from any hematopoietic tissue, but do not have a clear localization (develop in the blood).

· mutation theory: carcinogens (i.e. factors that cause cancer) lead to mutations in the genetic apparatus of cells. Cells begin to divide randomly. Factors that cause cell mutations are called mutagens.

· immunological theory: even in a healthy body, single cell mutations and their tumor transformation constantly occur. But normally, the immune system quickly destroys the “wrong” cells. If the immune system is impaired, then one or more tumor cells are not destroyed and become a source of tumor development.

There are other theories that deserve attention, but I will write about them separately in my blog.

Modern views on the occurrence of tumors.

For the occurrence of tumors must have:

· internal reasons:

1. genetic predisposition

2. certain immune system conditions.

· external factors (they are called carcinogens, from lat. cancer- cancer):

1. mechanical carcinogens: frequent tissue trauma followed by regeneration (restoration).

2. physical carcinogens: ionizing radiation (leukemia, bone tumors, thyroid gland), ultraviolet radiation (skin cancer). Published data show that every sunburn of the skin significantly increases the risk development of a very malignant tumor - melanoma in the future.

3. chemical carcinogens: exposure to chemicals throughout the body or only in a specific location. Benzopyrene, benzidine, components of tobacco smoke and many other substances have oncogenic properties. Examples: lung cancer from smoking, pleural mesothelioma from working with asbestos.

4. biological carcinogens: in addition to the viruses already mentioned, bacteria have carcinogenic properties: for example, prolonged inflammation and ulceration of the gastric mucosa due to infection Helicobacter pylori may end malignancy.

3. Mutation theory

It is now a generally accepted concept that cancer is a genetic disease based on changes in genomecells. In the vast majority of cases, malignant neoplasms develop from a single tumor cell, that is, they are of monoclonal origin. Based on the mutation theory, cancer occurs due to the accumulation of mutations in specific areas of cellular DNA, leading to the formation of defective proteins.

Major milestones in the development of the mutation theory of carcinogenesis:

· 1914 - German biologist Theodore Boveri suggested that abnormalities in chromosomes can lead to cancer.

· 1927 - Hermann Müller discovered that ionizing radiation causes mutations.

· 1951 - Müller proposed a theory according to which mutations are responsible for the malignant transformation of cells.

· 1971 - Alfred Knudson explained differences in the incidence of hereditary and non-hereditary forms of retinal cancer ( retinoblastoma) by the fact that for a mutation in the RB gene both of it must be affected allele, and one of the mutations must be inherited.

· in the early 1980s, transfer of the transformed phenotype using DNA from malignant cells (spontaneously and chemically transformed) and tumors to normal ones. In fact, this is the first direct evidence that the hallmarks of transformation are encoded in DNA.

· 1986 - Robert Weinberg first identified a tumor suppressor gene.

· 1990 - Bert Vogelstein And Eric Faron published a map of sequential mutations associated with rectal cancer. One of the achievements of molecular medicine in the 90s. provided evidence that cancer is a genetic multifactorial disease.

· 2003 - The number of identified genes associated with cancer exceeded 100 and continues to grow rapidly.

4. Proto-oncogenes and tumor suppressors

Direct evidence of the mutational nature of cancer can be considered the discovery of proto-oncogenes and suppressor genes, changes in the structure and expression of which due to various mutational events, including point mutations, leads to malignant transformation.

Discovery of Cellular proto-oncogenes was first carried out using highly oncogenic RNA viruses ( retroviruses), carrying as part of their genome transformative genes. Molecular biological methods have established that the DNA of normal cells of various types eukaryotes contains sequences homologous to viral oncogenes, which are called proto-oncogenes. Conversion of cellular proto-oncogenes into oncogenes can occur as a result of mutations in the coding sequence of a proto-oncogene, which will lead to the formation of an altered protein product, or as a result of an increase in the level of expression of a proto-oncogene, as a result of which the amount of protein in the cell increases. Proto-oncogenes, being normal cellular genes, are highly evolutionarily conserved, indicating their participation in vital cellular functions.

Point mutations leading to the transformation of proto-oncogenes into oncogenes have been studied mainly using the example of activation of proto-oncogenes of the family ras. These genes, first cloned from human tumor cells at bladder cancer, play an important role in the regulation proliferation cells both normally and in pathology. Genes of the family ras represent a group of proto-oncogenes that are most often activated during tumor degeneration of cells. Mutations in one of the HRAS, KRAS2, or NRAS genes are found in approximately 15% of human cancers. 30% of lung adenocarcinoma cells and 80% of pancreatic tumor cells have a mutation in the oncogene ras, which is associated with a poor prognosis of the disease.

One of the two hotspots in which mutations lead to oncogenic activation is the 12th codon. In experiments on directional mutagenesis it was shown that the substitution in the 12th codon glycine for any amino acid, with the exception of proline, leads to the appearance of a transforming ability in the gene. The second critical region is located around codon 61. Replacement glutamine at position 61 to any amino acid except proline and glutamic acid, also leads to oncogenic activation.

Antioncogenes, or tumor suppressor genes, are genes whose product inhibits tumor formation. In the 80-90s of the 20th century, cellular genes were discovered that exercise negative control of cell proliferation, that is, preventing cells from entering into division and leaving a differentiated state. Loss of function of these antioncogenes causes uncontrolled cell proliferation. Due to their opposite functional purpose to oncogenes, they were called anti-oncogenes or malignancy suppressor genes. Unlike oncogenes, mutant alleles of suppressor genes are recessive. The absence of one of them, provided that the second is normal, does not lead to the removal of inhibition of tumor formation.

Currently, there are two main theories of the occurrence of neoplasms - this theory and “tumor field” theory.

According to theory monoclonal origin, the original carcinogenic agent (tumor-causing factor) causes mutations single cell , upon division of which a tumor clone then arises, constituting a neoplasm. The monoclonal origin of neoplasms has been proven in the example of tumors from B-lymphocytes (B-cell lymphomas and plasma cell myelomas), the cells of which synthesize immunoglobulins of the same class, as well as in some other types of tumors. It has also been shown that as a tumor progresses, subclones can develop from the initial clone of tumor cells as a result of additional ongoing genetic changes ("multiple kicks"; see below).

“Tumor field” theory: a carcinogenic agent, acting on a large number of similar cells, can cause the formation fields of potentially neoplastic cells . The neoplasm may then develop as a result of the proliferation of one or more cells within this field. In many cases, the result is several distinct neoplasms, each derived from a distinct clonal precursor. The formation of a tumor field can be regarded as the first of two or more successive steps that lead to tumor development ("multiple shocks"; see below). This theory explains the origin of some neoplasms in the skin, epithelium of the urinary tract, liver, mammary gland and intestines. Recognition of the existence of a tumor field is of practical importance, since the presence of one neoplasm in any of these organs should alert the clinician to the possibility of the presence of a second similar neoplasm. In the mammary glands, for example, the development of cancer in one of them is a risk factor for cancer in the opposite one (statistically, the risk increases approximately 10 times compared to the overall incidence of breast cancer).

To explain the mechanisms of occurrence of both the tumor monoclone and the “tumor field,” a number of other concepts have currently been proposed.

The theory of genetic mutations. Disturbances in the genome caused by heredity, spontaneous mutations or the action of external agents can cause neoplasia if growth-regulating genes are damaged. Tumor transformation occurs as a result of the activation (or derepression) of specific DNA sequences known as growth-regulating genes, or proto-oncogenes. These genes encode a number of growth factors and growth factor receptors. Activation is a functional change in which the normal growth regulation mechanism in tumorigenesis is disrupted. Activation can occur in several ways: mutation of proto-oncogenes; translocation to a more active part of the genome, where regulatory influences activate proto-oncogenes; insertion of an oncogenic virus into the active part of the genome; amplification (production of multiple copies of proto-oncogenes); insertion of viral oncogenes; derepression (loss of suppressor control). The resulting functionally activated gene is called an "activated oncogene" (or mutant oncogene if it is structurally altered), or simply as a cellular oncogene (c-onc). An increase in the production of stimulating growth factors or their receptors, or a decrease in inhibitory (suppressor) growth factors, or the production of functionally abnormal factors can lead to uncontrolled cell growth. Thus, at the molecular level, neoplasia represents a dysfunction of growth-regulating genes (proto-oncogenes and tumor suppressor genes).

Theory of viral oncogenes. Some RNA viruses contain nucleic acid sequences that are complementary to the proto-oncogene and can (by the action of reverse transcriptase) synthesize a viral DNA sequence that is essentially identical. These sequences are called viral oncogenes (v- onc). Many, perhaps all, oncogenic RNA retroviruses contain such sequences and they are found in the corresponding neoplasms. It is currently assumed that oncogenic RNA viruses acquire v- onc sequences by insertion of a cellular oncogene from an animal or human cell using a mechanism similar to that involved in recombination. Oncogenic DNA viruses also contain sequences that function as oncogenes and are inserted directly into the cell's genome.

Epigenetic theory. According to the epigenetic theory, the main cellular damage occurs not in the genetic apparatus of the cell, but in the mechanism for regulating gene activity, especially in proteins, the synthesis of which is encoded by growth-regulating genes. Different levels of activity of genes that are responsible for tissue differentiation are thought to be determined by inherited epigenetic mechanisms. The main evidence of the role of epigenetic mechanisms in the processes of oncogenesis is found in the formation of tumors under the influence of certain chemicals that have no effect on the genetic apparatus of the cell. The action of some of these substances is to bind cytoplasmic proteins, and changes in them are believed to contribute to the occurrence of certain neoplasms, i.e. these substances act as promoters.

Immune surveillance failure theory. According to this theory, neoplastic changes occur quite often in the cells of the body. As a result of DNA damage, neoplastic cells synthesize new molecules (neoantigens, tumor antigens; see Fig. 2). The body's immune system recognizes these neoantigens as “foreign,” which leads to the activation of a cytotoxic immune response that destroys neoplastic cells. Clinically detectable neoplasms occur only if they are not recognized and destroyed by the immune system. Proof of this theory is that a higher incidence of tumors is observed in immunodeficient patients and in patients receiving immunosuppressive therapy after organ transplantation. An explanation for the fact that cancer is primarily a disease of the elderly may be that there is a progressive decline in immune reactivity in old age, coupled with an increase in the incidence of neoplastic changes arising from defects in DNA repair that occur with aging. Against this theory the following facts indicate: in mice with insufficient T-cell immunity, the frequency of neoplasms does not increase; people with immunodeficiencies develop primarily lymphomas rather than the full range of different tumors; in people with the thymus removed, the incidence of tumors does not increase; Although many tumors synthesize tumor antigens and the immune response to them develops sufficiently, this response is often ineffective.

To date, there is no exact theory of the origin of a cancerous tumor, and many doctors and scientists argue about this. So far, there is a general theory to which everyone is inclined - that cancer arises as a result of mutation of genes inside cells in both men, women, and young children.

With the development of technology, more and more theories are appearing that have a place, but have not yet been 100% proven. If scientists understand where a cancerous tumor comes from, they will be able to predict this disease in people and destroy it in the bud.

It is not yet possible to answer the question of where cancer comes from, but we will provide you with several theories, and you will decide which one is the most plausible. We recommend reading this article in its entirety, it will completely change your understanding of cancer.

When did the cancer appear?

Not only humans, but also animals and some plant species suffer from cancer and other tumors. This disease has always existed in our history. The oldest mention was in 1600 BC in Egypt. Ancient papyri described a malignant neoplasm of the mammary glands.

The Egyptians treated cancer with fire, cauterizing the damaged area. Poisons and even arsenic were also used for cauterization. They did the same in other parts of the world, for example, in the Ramayana.


The word “cancer” was first introduced into the designation by Hippocrates (460-377 BC). The name itself is taken from the Greek “karkinos”, which means “Cancer” or “Tumour”. So it designated any malignant neoplasm with inflammation of nearby tissues.

There was another name “Oncos”, which also means tumor formation. A world-famous physician already at that time first described carcinoma of the gastrointestinal tract, uterus, intestines, nasopharynx, tongue and mammary glands.

In ancient times, external tumors were simply removed, and the remaining metastases were treated with ointments and oils mixed with poison. On the territory of Russia, moxibustions using tincture and ointment of hemlock and celandine were often used. And in other countries where these plants did not grow, they burned them with arsenic.

Unfortunately, internal tumors were not treated in any way and the patients simply died. The famous Roman healer Galen in 164 AD already described tumors with the word “tymbos”, which translated means “tombstone hill”.


Even then, he realized that early diagnosis and detection of the disease at an early stage gives a positive prognosis. Later, he tried to pay attention specifically to the description of the disease. He, like Hippocrates, used the word onkos, which later became the root of the word “Oncology”.

Aulus Cornelius Celsus in the 1st century BC tried to treat cancer only in the first stages, and in the last stages the therapy no longer gave any result. The disease itself has been rarely described. There is no mention of it even in honey. Chinese book “Classics of Internal Medicine of the Yellow Emperor”. And there are two reasons:


  1. Most healers did not describe the disease, but tried to treat it.
  2. The incidence of cancerous tumors was quite low. And at this time, the peak has come due to a technical breakthrough in the century, factories, industry, etc.

The first more accurate description began in the mid-nineteenth century by the physician Rudolf Vircherow. He described the mechanism of spread and growth of cancer cells. But oncology as a branch of medicine was founded only in the mid-twentieth century, when new diagnostic methods appeared.

Problem of the 21st century

Yes, cancer has always existed, but it was not on such a scale as it is now. The number of diseases is growing every decade, and the problem can affect every family, literally in 50-70 years.


Another problem is that the cause has not yet been clarified. Many scientists and oncologists argue about the occurrence of the disease. There are quite a few theories and each provides some aspect and lifts the mystery of the origin of the disease. But there are also those who contradict each other, and there is no common answer to the question - where does oncology come from? - Not yet.

Hepatogenic theory

At the end of the 30s of the 20th century, a group of German scientists studied cancer based on the so-called “cancer houses”. People living there constantly suffered from cancer, and doctors came to the conclusion that this could be indicated by a hepatogenic factor. Later they even began to produce some protection against this radiation, although they themselves did not know how to detect it.

The International Congress of Oncology later refuted this theory. But later she returned. Hepatogenic zones: faults in the ground, voids, intersections of water flows, subway tunnels, etc. These zones drain energy from a person during a long stay.


Hepatogenic rays have a diameter of up to 35 cm and can grow up to the 12th floor. When exposed to the area during sleep, rest or work, the affected organs are at risk of any diseases, including cancer. These zones were first described in the 50s of the last century by Ernst Hartmann, he called them “Hartmann’s grid”.

The doctor described the occurrence of cancer in six hundred pages. His theory was that it was the immune system that was being suppressed. And as we know, it is she who first begins to fight mutated cells and destroys them in the first stages. If anyone is interested, you can always find and read his book published in the 60s of the 20th century - “Diseases as a problem of location.”

One of the famous doctors at that time, Dieter Aschof, told his patients to check their places of work and home with the help of dowsing specialists. Three doctors from Vienna, Hochengt, Sauerbuch and Notanagel, advised cancer patients to immediately move from their homes to another place.

Statistics

  • 1977 — Ocnologist Kasyanov examined more than four hundred people who lived in the hepatogenic zone. The study showed that these people suffered from various diseases more often than others.
  • 1986 — A Polish doctor examined more than a thousand patients who slept and lived in geopathogenic zones. Those who slept at the intersection of the rays fell ill for 4 years. 50% are mild diseases, 30% are moderate, 20% are fatal.
  • 1995 - English oncologist Ralph Gordon found that breast cancer and lung cancer are more common in people living in hellish zones. Let us remember that, according to statistics, these are the two most common diseases in men and women.
  • 2006 — Ilya Lubensky introduced the concept of “hepatogenic syndrome”. He even came up with a rehabilitation technique for people who were influenced by anomalous rays.

Virus theory

In 2008, Harold Zurhausen received the Nobel Prize for proving that viruses can cause cancer. He proved this with the example of cervical cancer. At the same time, many Soviet and Russian scientists and doctors of the last century also put forward this theory, but could not prove it due to the scarcity of technology and diagnostic equipment.

The Soviet scientist Leah Zilber first wrote about this theory. He sat in a concentration camp and wrote his theory on a piece of tissue paper. Later, his son Fyodor Kiselev continued his father’s idea and developed a work together with Zurhausen in which the main enemy was the human papillomavirus (HPV), which could cause cancer. Later, in large countries, almost all women began to receive HPV vaccinations.

Genetic theory

The essence of the theory is that there is an influence, both external and internal, on genes during the process of cell division and during ordinary life. As a result, the genetics of the cells break down, and they mutate, turning into cancer. Afterwards, such tissues begin to endlessly divide and grow, absorbing and damaging nearby organs.

As a result, scientists found so-called oncogenes - these are genes that, under certain conditions and external factors, begin to degenerate any cell in the body into cancer. Before this state, such genes are in a dormant state.

That is, a gene is that part of the program code in the body that begins to work only at a certain moment and under certain conditions. This is why the risk of getting sick is higher for people whose parents had cancer than for others.


But we must remember that all mutated or broken cells are fought by our immune system, which constantly scans the body for breakdowns and destroys careless cells.

And if immunity is lowered, then the chance of getting sick is greater. This is especially dangerous for a child at an early age, when he has already stopped receiving mother’s milk as food. And also when the remaining stem cells divide, they are more vulnerable to changes in tissue DNA molecules in babies.

Today, this theory is the main and most widespread, which is used by almost all oncologists and physicians. Since all other theories are largely just a risk factor, be it viruses or hepatogenic in nature.

Plus, he noticed that cancer cells do not form tissue like living ones, and the tumor is more like a large colony. Nevyadomsky believed that tumor cells are foreign organisms like chlamydia.

O.I. Eliseeva, Candidate of Medical Sciences, oncologist, who has been studying cancer tumors for 40 years, came up with the theory that a tumor is a structure of interaction between fungi, microbes and viruses, as well as protozoa. Initially, a fungus appears on the spot, on which viruses and microorganisms with protozoa develop further.


H. Clark suggested and wrote in his work that a cancerous tumor appears at the place of life of a trematode, a flatworm. And if you kill him, the spread of cancer will stop. His other theory is chemical - under the influence of benzene and propylene. At the same time, in order for cancer to begin to occur, you need to accumulate a sufficient amount of these substances.

And now an interesting fact - ALL the sick people examined by Dr. Clark had propylene and trematodes in their bodies. He studied factors in everyday life that affect everyone where propylene is located:

  1. Dentures, crowns.
  2. Freon from refrigerators.
  3. Bottled water.
  4. Deodorants.
  5. Tooth pastes.
  6. Refined oils.

Added to this was another theory about radiation, which arose in 1927 and was invented by Hermann Müller. He saw that as a result of exposure to radiation and all types of rays, cells begin to mutate and cancer can occur. True, the irradiation was carried out on animals, and not in the laboratory directly on tissue.

Scientists have noticed that cancer cells mainly arise in an acidic environment. In such an environment, the immune system and all nearby tissues of the body weaken. But if the environment is made alkaline, then everything will be the other way around and cancer cells simply will not be able to survive in it, but the immune system will be normal. Because of this, there is a rather old and good method of treating and restoring the alkaline balance with calcium and.

Biochemistry and cancer

In our age, chemicals, substances, pesticides and other harmful substances are found quite often. The basis of the theory is that all these substances affect every cell of the body. As a result, immunity drops significantly, and a favorable environment for the emergence of cancer cells appears in the body.

Proponents of the immune theory believe that cancer cells arise constantly during life, but the immune system periodically destroys them. With any impact within the body and during the regeneration process, our cells grow and clog both internal and external wounds. And the whole process is controlled by the immune system.

But with constant irritation and wound healing, mutation may occur and control may cease. This theory was first proposed by Rudolf Ludwig. Yamagaw and Ishikawa from Japan conducted a couple of tests. They put chemical on the rabbits' ears. carcinogen. As a result, after a few months a tumor appeared. The problem was that not all substances affected the occurrence of cancer.

Trichomonas

The founder of this theory is Otto Warburg. He discovered in 1923 that cancer cells actively break down glucose. And in 1955, he put forward a theory according to which malignant cells, when mutated, begin to behave like primitive Trichomonas, can move, cease to carry out the program laid down at the very beginning and grow and multiply very quickly.


In the process, their flagella, with the help of which they moved, disappear as unnecessary. As mentioned earlier, many scientists have noticed that cancer cells can move and move like protozoa, and subsequently spread throughout the body, forming new colonies, even under the skin.

Each person has three types of Trichomonas: in the oral cavity, intestines and in the reproductive system. This is where cancer most often occurs. In this case, before this, some kind of inflammation of the cervix, prostatitis, etc. occurs. Moreover, Trichomonas themselves, without flagella, are indistinguishable from human epithelial tissues in the blood. And there are quite a lot of types of protozoa.

A few facts

  1. In the laboratory, under any conditions, not a single doctor or scientist in the world has been able to turn a normal cell into a cancer cell. By influencing it with both chemical reagents and radiation.
  2. No one has been able to initiate metastasis in the laboratory.
  3. The DNA of a cancer cell is 70% similar to the DNA of protozoa, similar to Trichomonas.

NOTE! And at the same time, no one takes the theory of Otto and Svishcheva as a basis. Everyone talks about genetic mutation as the dominant theory, and no one has found the right answer. Maybe the problem is that scientists and doctors are looking the other way?! It is not yet clear why this theory is not being explored.


Oncological tumors arise as a result of disruption of the circulation of internal energy through the jilo channels, according to Chinese theory. At the same time, the energy of space, entering and leaving, must circulate according to certain rules. When the law is violated, disruptions occur in the body: a decrease in immunity, the occurrence of any diseases, including tumor diseases.


All this came to us from Eastern medicine. Each cell emits its own biofield, and in the complex there is a general radiation in the form of an egg. If this field weakens, then the body begins to be attacked by viruses, fungi and microorganisms, which can lead to malignant formations.

Any sore, additional disease, is the reason that the biofield begins to spin in the other direction. And the patient feels painful symptoms, his mood worsens and the biofield fades even more. But speaking in general, the theory here is based on the effect rather than on the cause.

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