Cancer: Causes and risk factors

Cancer: Causes and risk factors

Section 1: Basics of Cancer

Cancer, or a malignant tumor, is a group of diseases characterized by uncontrolled growth and the spread of abnormal cells. Unlike normal cells that grow, share and die in an orderly way, cancer cells continue to grow and share without obeying these signals. This uncontrolled growth can lead to the formation of tumors that can invade the surrounding tissues and organs and metastasize, that is, spread to other parts of the body.

1.1. Cell cycle and regulation

The normal cell cycle is a strictly adjustable process that provides the correct division and growth of cells. This cycle consists of several phases, including the growth phase (G1), the DNA synthesis phase, the phase of preparation for division (G2) and the division phase (M). In each phase there are control points that check whether the process proceeds correctly, and allow the cell to correct errors or initiate apoptosis (programmed cell death) if errors cannot be corrected.

The regulation of the cell cycle is carried out by a complex network of proteins, including cyclines and cyclin-dependent kinase (CDK). Cyclins are associated with CDK, activating them and allowing them to phosphorying other proteins involved in the regulation of the cell cycle. Various combinations of cyclines and CDK activate various phases of the cell cycle.

1.2. Genes and cancer

The development of cancer is often associated with mutations in certain genes that play an important role in the regulation of the cell cycle, DNA reparations and apoptosis. These genes can be divided into two main categories: protoncogen and tumors-genes.

Proto -acting: These are genes that stimulate the growth and division of cells. When the proto -oxogen is mutated, they turn into oncogenes, which can cause uncontrolled cell growth. Oncogenes often lead to excessive activation of signal tracts, which stimulate cellular growth and division. Examples of oncogenes are RAS, MYC And ERBB2.
Tumor Suppressors genes: These are genes that inhibit the growth and division of cells or contribute to apoptosis. When the tumor-soup genes are mutated, they lose their function, allowing cells to grow and share in an uncontrolled way. Examples of tumor-soup genes are TP53, RB1 And BRCA1/2.

1.3. Mechanisms of carcinogenesis

Carcinogenesis, or cancer development, is a multi -stage process that includes the accumulation of genetic and epigenetic changes in cells. This process usually consists of three main stages: initiation, promotion and progression.

Initiation: At this stage, a normal cell is exposed to a carcinogenic agent, which causes a mutation in its DNA. This mutation can affect the proto-ogogen or the tumor-gene.
Promotion: At this stage, a cage with a mutation is exposed to another factor that stimulates its growth and division. This factor, called the promotor, in itself does not cause mutations, but contributes to the development of cancer in a cell that already has a mutation.
Progression: At this stage, cancer cells acquire additional mutations and become more aggressive. They can invade the surrounding tissues and organs, metastasize into other parts of the body and become resistant to therapy.

1.4. Types of cancer

Cancer is classified depending on the type of cells from which it develops, and localization of the primary tumor. There are more than 100 different types of cancer, some of the most common of them include:

Cancer: Cancer, which develops from epithelial cells that lift the surfaces of the body and organs. Carcinomas are the most common type of cancer and include lung cancer, breast cancer, colon cancer and prostate cancer.
Sarkoma: Cancer, which develops from connective tissue, such as bones, cartilage, muscles and fat. Sarcomes are relatively rare.
Leukemia: Blood cancer that develops in the bone marrow. Leukemia is characterized by uncontrolled growth of abnormal leukocytes.
Lymphoma: Cancer of the lymphatic system, which includes lymph nodes, spleen and thymus. Lymphomas are characterized by uncontrolled growth of abnormal lymphocytes.
Melanoma: Skin cancer, which develops from melanocytes, cells that Melanin produce. Melanoma is the most dangerous type of skin cancer.

Section 2: Causes of cancer

Cancer is a multifactor disease, that is, its development is due to a combination of genetic and environmental factors. Some of the main causes of cancer include:

2.1. Genetic factors

Genetic factors play an important role in the development of cancer. Mutations in genes that regulate the cell cycle, DNA reparation and apoptosis can increase the risk of cancer. These mutations can be inherited from parents or acquired throughout life as a result of exposure to carcinogenic agents.

Hereditary mutations: In some cases, people inherit mutations in genes that increase the risk of developing certain types of cancer. For example, mutations in genes Krca1 And BRCA2 Significantly increase the risk of breast cancer and ovarian cancer. Other hereditary cancer syndromes include Li-Franei syndrome (mutations in gene TP53), linch syndrome (mutations in DNA reparation genes) and family adenomatous polyposis (mutations in gene APC).
Acquired mutations: Acquired mutations occur in cells during a person’s life as a result of exposure to carcinogenic agents, such as tobacco smoke, ultraviolet radiation and some chemicals. These mutations can accumulate over time and ultimately lead to the development of cancer.

2.2. Environmental factors

Environmental factors play a significant role in the development of cancer. The effect of carcinogenic agents contained in the environment can cause mutations in cell DNA and increase the risk of cancer. Some of the main environmental factors associated with cancer include:

Tobacco smoke: Tobacco smoke is one of the main risk factors for the development of lung cancer, as well as cancer of the oral cavity, throat, esophagus, bladder, kidneys, pancreas and cervix. Tobacco smoke contains more than 7000 chemicals, many of which are carcinogenic.
Ultraviolet radiation: Ultraviolet (UV) radiation from the sun or solariums is the main risk factor for the development of skin cancer, including basal cell cancer, flat cell cancer and melanoma. UV radiation damages the DNA of skin cells, which can lead to mutations and the development of cancer.
Radiation: The effect of ionizing radiation, such as x-rays, gamma rays and radioactive substances, can increase the risk of cancer, including leukemia, thyroid cancer and breast cancer.
Chemicals: The impact of certain chemicals in the workplace or in the environment can increase the risk of cancer. For example, the effect of asbestos is associated with lung cancer and mesothelioma, and the effect of benzene is associated with leukemia.
Air pollution: Air pollution with solid particles and other pollutants is associated with an increased risk of lung cancer.

2.3. Life lifestyle factors

Life lifestyle factors play an important role in the development of cancer. Some of the main factors of lifestyle associated with cancer include:

Diet: A diet rich in red and treated meat, fats and sugar, and poor fruits, vegetables and whole grain products can increase the risk of developing colon, breast cancer and prostate cancer. On the other hand, a diet rich in fruits, vegetables and whole grains can reduce the risk of developing certain types of cancer.
Obesity: Obesity is associated with an increased risk of developing many types of cancer, including breast cancer, colon cancer, endometrial cancer, kidney cancer, pancreatic cancer and pancreatic cancer. Obesity can lead to chronic inflammation and hormonal changes that can contribute to the development of cancer.
Physical activity: Low physical activity is associated with an increased risk of developing colon cancer, breast cancer and endometrial cancer. Regular physical activity can help reduce the risk of developing these types of cancer.
Alcohol consumption: The use of alcohol is associated with an increased risk of developing cancer of the oral cavity, throat, esophagus, liver, breast and colon. The risk of cancer develops with an increase in the amount of alcohol consumed.
Smoking: Smoking is the main risk factor for the development of lung cancer, as well as cancer of the oral cavity, throat, esophagus, bladder, kidneys, pancreas and cervix.

2.4. Infectious agents

Some infectious agents, such as viruses and bacteria, can cause cancer. Some of the most common infectious agents associated with cancer include:

Human papilloma virus (HPV): HPV is the cause of most cases of cervical cancer, as well as vaginal cancer, vulva, anus, penis and oropharynx. Vaccination against HPV can help prevent these types of cancer.
Hepatitis B virus (VGV) and hepatitis C virus (HCC): HRV and HCC can cause chronic hepatitis, which can lead to liver cancer. Vaccination against HRV and HIG treatment can help prevent liver cancer.
Helicobacter Pylori: Helicobacter pylori is a bacterium that can cause stomach ulcers and increase the risk of gastric cancer. Helicobacter pylori infection can help reduce the risk of gastric cancer.
Human immunodeficiency virus (HIV): HIV weakens the immune system, which increases the risk of developing some types of cancer, such as the sarcoma of Kaposhi, lymphoma and cervical cancer.

Section 3: Risk risk factors for cancer

Risk risk factors are factors that increase the likelihood of cancer in humans. The presence of one or more risk factors does not mean that a person will definitely get cancer, but this means that his risk of cancer is higher than a person who does not have these risk factors. Some of the main risk factors for cancer include:

3.1. Age

Age is one of the main risk factors for cancer. The risk of developing most types of cancer increases with age, since over time the cells accumulate genetic mutations. In addition, the immune system with age becomes less effective, which complicates the detection and destruction of cancer cells.

3.2. Family history

Family history of cancer can increase the risk of cancer in humans. If a person has close relatives (parents, brothers, sisters, children) who had cancer, he may have an increased risk of developing the same type of cancer or other types of cancer. This may be associated with the inheritance of mutations in genes that increase the risk of cancer, or with general environmental factors and lifestyle in the family.

3.3. Floor

Some types of cancer are more common in men, while others are found in women. For example, prostate cancer is found only in men, and cervical cancer is only in women. Breast cancer is much more common in women than in men. These differences in the incidence of cancer between men and women can be associated with hormonal differences, anatomical features and lifestyle factors.

3.4. Race and ethnicity

Some races and ethnic groups have a higher risk of developing certain types of cancer. For example, African Americans have a higher risk of developing prostate cancer, colon cancer and breast cancer than white Americans. Asians and residents of the Pacific Islands have a higher risk of developing liver and stomach cancer. These differences in the incidence of cancer between different races and ethnic groups can be associated with genetic factors, environmental factors and lifestyle factors.

3.5. The state of the immune system

People with a weakened immune system, for example, due to HIV infection, transplantation of organs or autoimmune diseases, have an increased risk of developing some types of cancer, such as caposhi sarcoma, lymphoma and cervical cancer. The weakened immune system is less effective in the detection and destruction of cancer cells.

3.6. Chronic inflammatory diseases

Chronic inflammatory diseases, such as inflammatory intestinal diseases (Crohn’s disease and ulcerative colitis), can increase the risk of developing colon cancer. Chronic inflammation can damage cell DNA and promote cancer development.

3.7. The impact of estrogens

The prolonged exposure to estrogens, for example, with an early beginning of menstruation, late menopause or hormone replacement therapy, can increase the risk of breast cancer and endometrial cancer. Estrogens can stimulate the growth of breast cells and endometrium.

3.8. Previous cancer diseases

People who previously hurt cancer have an increased risk of developing another type of cancer. This may be due to the fact that they already have genetic mutations that increase the risk of cancer, or with the fact that they have exposed to chemotherapy or radiation therapy, which can increase the risk of cancer.

3.9. Some medicines

Some drugs can increase the risk of cancer. For example, prolonged use of birth control pills can slightly increase the risk of breast cancer and cervical cancer. Some immunosuppressants can increase the risk of lymphoma.

Section 4: Cancer Prevention

Although it is impossible to completely eliminate the risk of cancer, it is possible to reduce the risk of cancer by taking certain preventive measures. Some of the main measures of cancer prevention include:

4.1. Refusal of smoking

Refusal of smoking is one of the most important steps that can be taken to reduce the risk of cancer. Refusal of smoking reduces the risk of developing lung cancer, as well as cancer of the oral cavity, throat, esophagus, bladder, kidneys, pancreas and cervix.

4.2. Sun protection

Sun protection can help reduce the risk of skin cancer. Avoid staying in the sun during peak activity hours (from 10:00 to 16:00), wear protective clothes, such as hats and shirts with long sleeves, and use SPF 30 or higher sunscreen. Soloias should not be used.

4.3. Healthy diet

Healthy nutrition can help reduce the risk of cancer. A lot of fruits, vegetables and whole grain products should be eaten and limit the use of red and treated meat, fats and sugar. Healthy weight should be maintained.

4.4. Physical activity

Regular physical activity can help reduce the risk of developing colon cancer, breast cancer and endometrial cancer. It is recommended to engage in moderate physical activity of at least 150 minutes a week or intensive physical activity of at least 75 minutes a week.

4.5. Moderate drinking alcohol

Moderate drinking of alcohol can help reduce the risk of developing oral cancer, throat, esophagus, liver, breast and colon. If you drink alcohol, do it moderately. This means no more than one drink per day for women and no more than two drinks per day for men.

4.6. Vaccination

Vaccination against HPV and HBV can help prevent cervical cancer, as well as vaginal cancer, vulva, anus, penis and oropharynx (for HPV) and liver cancer (for HCV).

4.7. Regular medical examinations

Regular medical examinations, including cancer screening, can help identify cancer at an early stage when it is most treated. Cancer screening may include mammography (for breast cancer), colonoscopy (for cancer of the colon), a papa test (for cervical cancer) and a dog test (for prostate cancer).

4.8. Avoiding the effects of carcinogenic substances

The effects of carcinogenic substances, such as asbestos, benzene and other chemicals that can increase the risk of cancer, should be avoided.

Section 5: The role of scientific research

Scientific research plays a decisive role in understanding the causes of cancer, developing new methods of prevention, diagnosis and treatment of cancer. Studies in the field of genetics, molecular biology, immunology and other areas of science allow scientists to better understand the mechanisms of cancer development and develop new strategies for combating this disease.

Genetic research: Genetic studies help identify genes that increase the risk of cancer, and develop genetic therapy methods to correct mutations in these genes.
Molecular research: Molecular studies help to understand the molecular mechanisms that lead to cancer, and develop new drugs that affect these mechanisms.
Immunological studies: Immunological studies help to develop new immunotherapy methods that stimulate the immune system to combat cancer cells.
Clinical research: Clinical studies make it possible to evaluate the effectiveness of new methods of prevention, diagnosis and treatment of cancer in humans.

Continuing scientific research inspire the hope that in the future cancer will become more preventive, diagnosed at an early stage and successfully cured.

Section 6: Cancer diseases and their risk factors (examples)

6.1. Lung cancer

The main risk factors: Smoking (active and passive), exposure to asbestos, radon, air pollution, family history of lung cancer.
Reasons: Mutations in genes that regulate the growth and division of lung cells caused by the effects of carcinogens.
Prevention: Refusal of smoking, avoiding the effects of asbestos and radon, improving the quality of air.

6.2. Breast cancer

The main risk factors: The female gender, age (older than 50 years), a family history of breast cancer or ovaries, early onset of menstruation, late menopause, lack of childbirth or the first birth at a late age, hormonal therapy, obesity, alcohol, exposure to radiation.
Reasons: Mutations in genes Krca1, BRCA2, TP53 and others, hormonal factors, lifestyle factors.
Prevention: Maintaining healthy weight, regular physical activity, restriction of alcohol use, breastfeeding (if possible), screening (mammography).

6.3. Tolstoy’s cancer

The main risk factors: Age (older than 50 years), family history of colon cancer or colon polyps, inflammatory intestinal diseases (crown disease, ulcerative colitis), diet, rich and treated meat and poor fiber, obesity, smoking, alcohol consumption.
Reasons: Mutations in genes APC, KRAS, TP53 and others, chronic inflammation.
Prevention: Screening (colonoscopy, sigmoidoscopy, fecal analysis for hidden blood), diet, rich in fiber and poor in red and treated meat, maintaining healthy weight, regular physical activity, reservation of smoking, moderate drinking.

6.4. Prostate cancer

The main risk factors: Age (older than 50 years), African American origin, family history of prostate cancer, diet, rich in fats.
Reasons: Genetic factors, hormonal factors, environmental factors.
Prevention: There are no reliable methods for the prevention of prostate cancer, but some studies show that a diet rich in vegetables and fruits, and regular physical activity can reduce risk. Screening (PSA test) can help identify cancer at an early stage.

6.5. Skin cancer (melanoma)

The main risk factors: The effect of ultraviolet radiation (sun, solariums), light skin, red or blond hair, blue or green eyes, a large number of moles, a family history of melanoma.
Reasons: Damage to DNA of skin cells with ultraviolet radiation.
Prevention: Avoiding the sun stay during peak activity, wearing protective clothing, using sunscreen, avoiding the use of tanning beds, regular skin examination.

6.6. Cervical cancer

The main risk factors: The infection with the human papilloma virus (HPV), smoking, a weakened immune system, the early beginning of sexual activity, a large number of sexual partners.
Reasons: HPV infection that causes changes in the cervical cells.
Prevention: Vaccination against HPV, screening (papa test), rejection of smoking, using condoms.

6.7. Stomach cancer

The main risk factors: Infection Helicobacter pyloridiet, rich in smoked, salty and pickled foods and poor fruits and vegetables, smoking, family history of stomach cancer, atrophic gastritis, pernicious anemia.
Reasons: Infection Helicobacter pyloridamage to the mucous membrane of the stomach.
Prevention: Treatment of infection Helicobacter pyloria diet rich in fruits and vegetables and poor smoked, salty and pickled food, rejection of smoking.

6.8. Leukemia

The main risk factors: The impact of radiation, benzene, chemotherapy, genetic disorders (Down syndrome), smoking, family history of leukemia.
Reasons: Mutations in blood cells, leading to uncontrolled growth of abnormal leukocytes.
Prevention: Avoiding the effects of radiation and benzene, rejection of smoking.

6.9. Lymphoma

The main risk factors: Age, weakened immune system (HIV infection, organs transplantation), infection (Epstein-Barr virus, Helicobacter pylori), the effect of certain chemicals, autoimmune diseases.
Reasons: Lymphocytes leading to uncontrolled growth.
Prevention: There are no reliable methods for the prevention of lymphoma, but maintaining a healthy lifestyle and avoiding exposure to known carcinogenic substances can reduce risk.

Section 7: Conclusion (conditionally, without a clear designation)

Cancer is a complex and multifaceted disease, the development of which depends on the interaction of genetic factors, environmental factors and lifestyle. Understanding the causes and risk factors of cancer is crucial for the development of effective strategies for the prevention, early diagnosis and treatment of this disease. Continuing scientific studies allow us to deepen our knowledge about cancer and develop new, more effective methods of combating it. Taking prevention measures, such as smoking, protection from the sun, healthy nutrition, regular physical activity and vaccination, can significantly reduce the risk of cancer. Early detection of cancer through regular medical examinations and screening also plays an important role in improving treatment results. Information about the risk factors of cancer and taking prevention measures allow each person to contribute to the fight against this disease.

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