Cancer is the name given to a set of more than 100 diseases that share the common characteristic of uncontrolled (malignant) cell growth that invades tissues and organs, and can spread (metastasis) to other areas of the body.
Dividing rapidly, these cells tend to be very aggressive and uncontrollable, leading to the formation of tumors (accumulation of cancer cells) or malignant neoplasms. On the other hand, a benign tumor simply means a localized mass of cells that multiply slowly and resemble their original tissue, rarely posing a life risk.
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The different types of cancer correspond to the various types of body cells. For example, there are several types of skin cancer because the skin is composed of more than one type of cell. If cancer starts in epithelial tissues like skin or mucous membranes, it is called carcinoma. If it begins in connective tissues like bone, muscle, or cartilage, it is called sarcoma.
Other characteristics that differentiate the various types of cancer from each other are the speed of cell multiplication and the ability to invade neighboring or distant tissues and organs (metastasis). |
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What causes cancer?
The causes of cancer are varied, and can be external or internal to the body, both being interrelated. External causes relate to the environment and habits or customs inherent to a social and cultural environment. Internal causes are, most often, genetically predetermined and are linked to the body's ability to defend itself against external aggressions. These causal factors can interact in various ways, increasing the probability of malignant transformations in normal cells.
Out of all cases, 80% to 90% of cancers are associated with environmental factors. Some of these are well-known: smoking can cause lung cancer, excessive sun exposure can cause skin cancer, and some viruses can cause leukemia. Others are under study, such as some components of the foods we eat, and many are still completely unknown. Aging brings about changes in cells that increase their susceptibility to malignant transformation. This, combined with the fact that the cells of older individuals have been exposed for a longer time to different cancer risk factors, partly explains why cancer is more frequent in these individuals. Environmental risk factors for cancer are called carcinogens. These factors act by altering the genetic structure (DNA) of cells.
The onset of cancer depends on the intensity and duration of cell exposure to cancer-causing agents. For example, a person's risk of developing lung cancer is directly proportional to the number of cigarettes smoked per day and the number of years they have been smoking.
Environmental Risk Factors
Cancer risk factors can be found in the environment or can be inherited. Most cancer cases (80%) are related to the environment, where we find a large number of risk factors. Environment is understood as the general surroundings (water, land, and air), the occupational environment (chemical and related industries), the consumption environment (food, medication), and the social and cultural environment (lifestyle and habits).
Changes brought about in the environment by humans themselves, and the 'habits' and 'lifestyle' adopted by people, can lead to different types of cancer.
Smoking
Dietary Habits
Alcoholism
Sexual Habits
Medications
Occupational Factors
Solar Radiation
Heredity
Cases of cancer due exclusively to hereditary, familial, and ethnic factors are rare, although the genetic factor plays an important role in oncogenesis. An example is individuals with retinoblastoma who, in 10% of cases, have a family history of this tumor.
Some types of breast, stomach, and intestinal cancer appear to have a strong family component, although the hypothesis of family members being exposed to a common cause cannot be ruled out. Certain ethnic groups seem to be protected from certain types of cancer: lymphocytic leukemia is rare in East Asians, and Ewing's sarcoma is very rare in Black individuals.
10 Tips for Risk Factor Reduction
| Ten Tips to Protect Yourself from Cancer |
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1. Stop smoking! This is the most important rule for preventing cancer.
2. A healthy diet can reduce cancer chances by at least 40%. Eat more fruits, vegetables, leafy greens, and cereals, and less fatty, salty, and canned foods. Your diet should include at least five servings of fruits, vegetables, and leafy greens daily. Prefer vegetable-based fats such as extra virgin olive oil, soybean oil, and sunflower oil, among others, always remembering that they should not be exposed to high temperatures. Avoid animal fats (milk and dairy products, pork, red meat, chicken skin, etc.) and some vegetable fats like margarine and hydrogenated vegetable fat.
3. Avoid or limit the intake of alcoholic beverages. Men should not drink more than two drinks per day, while women should limit this consumption to one drink. Additionally, engage in moderate physical activity for at least 30 minutes, five times a week.
4. It is advisable for men, between 50 and 70 years old, during a medical consultation, to be informed about the need to investigate prostate cancer.
5. Men over 45 years old with a family history of father or brother with prostate cancer before age 60 should consult a doctor for prostate cancer screening.
6. Women, aged 40 or over, should have a clinical breast exam annually. In addition, all women between 50 and 69 years old should have a mammogram every two years. Women with a family history of breast cancer (mother, sister, daughter, etc., diagnosed before age 50), or those who have had ovarian cancer or cancer in one breast, at any age, should undergo clinical examination and mammography starting at 35 years of age, annually.
7. Women between 25 and 59 years old should undergo a gynecological preventive exam. After two consecutive normal exams, one exam should be performed every three years. For abnormal exams, follow medical advice.
8. It is recommended that women and men, aged 50 or over, undergo a fecal occult blood test annually (preferably), or every two years.
9. During leisure time, avoid prolonged sun exposure, between 10 AM and 4 PM, and always use adequate protection such as a hat, umbrella, and sunscreen. If you are exposed to the sun during your workday, wear a wide-brimmed hat, long-sleeved shirt, and long pants.
10. Perform daily oral hygiene (brushing) and visit the dentist regularly. |
Sources: INCA/MS, 2002. Prevention and Control of Cancer. Brazilian Journal of Cancerology, 2002, 48(3):317-332
INCA/MS, 2002. National Program for Prostate Cancer Control: consensus document
INCA/MS, 2003. Consensus for Breast Cancer Control
Cancer is the name given to a set of more than 100 diseases that share the common characteristic of uncontrolled (malignant) cell growth that invades tissues and organs, and can spread (metastasis) to other areas of the body.
Dividing rapidly, these cells tend to be very aggressive and uncontrollable, leading to the formation of tumors (accumulation of cancer cells) or malignant neoplasms. On the other hand, a benign tumor simply means a localized mass of cells that multiply slowly and resemble their original tissue, rarely posing a life risk.
|
The different types of cancer correspond to the various types of body cells. For example, there are several types of skin cancer because the skin is composed of more than one type of cell. If cancer starts in epithelial tissues like skin or mucous membranes, it is called carcinoma. If it begins in connective tissues like bone, muscle, or cartilage, it is called sarcoma.
Other characteristics that differentiate the various types of cancer from each other are the speed of cell multiplication and the ability to invade neighboring or distant tissues and organs (metastasis). |
|
What causes cancer?
The causes of cancer are varied, and can be external or internal to the body, both being interrelated. External causes relate to the environment and habits or customs inherent to a social and cultural environment. Internal causes are, most often, genetically predetermined and are linked to the body's ability to defend itself against external aggressions. These causal factors can interact in various ways, increasing the probability of malignant transformations in normal cells.
Out of all cases, 80% to 90% of cancers are associated with environmental factors. Some of these are well-known: smoking can cause lung cancer, excessive sun exposure can cause skin cancer, and some viruses can cause leukemia. Others are under study, such as some components of the foods we eat, and many are still completely unknown. Aging brings about changes in cells that increase their susceptibility to malignant transformation. This, combined with the fact that the cells of older individuals have been exposed for a longer time to different cancer risk factors, partly explains why cancer is more frequent in these individuals. Environmental risk factors for cancer are called carcinogens. These factors act by altering the genetic structure (DNA) of cells.
The onset of cancer depends on the intensity and duration of cell exposure to cancer-causing agents. For example, a person's risk of developing lung cancer is directly proportional to the number of cigarettes smoked per day and the number of years they have been smoking.
Environmental Risk Factors
Cancer risk factors can be found in the environment or can be inherited. Most cancer cases (80%) are related to the environment, where we find a large number of risk factors. Environment is understood as the general surroundings (water, land, and air), the occupational environment (chemical and related industries), the consumption environment (food, medication), and the social and cultural environment (lifestyle and habits).
Changes brought about in the environment by humans themselves, and the 'habits' and 'lifestyle' adopted by people, can lead to different types of cancer.
Smoking
Dietary Habits
Alcoholism
Sexual Habits
Medications
Occupational Factors
Solar Radiation
Heredity
Cases of cancer due exclusively to hereditary, familial, and ethnic factors are rare, although the genetic factor plays an important role in oncogenesis. An example is individuals with retinoblastoma who, in 10% of cases, have a family history of this tumor.
Some types of breast, stomach, and intestinal cancer appear to have a strong family component, although the hypothesis of family members being exposed to a common cause cannot be ruled out. Certain ethnic groups seem to be protected from certain types of cancer: lymphocytic leukemia is rare in East Asians, and Ewing's sarcoma is very rare in Black individuals.
10 Tips for Risk Factor Reduction
| Ten Tips to Protect Yourself from Cancer |
|
1. Stop smoking! This is the most important rule for preventing cancer.
2. A healthy diet can reduce cancer chances by at least 40%. Eat more fruits, vegetables, leafy greens, and cereals, and less fatty, salty, and canned foods. Your diet should include at least five servings of fruits, vegetables, and leafy greens daily. Prefer vegetable-based fats such as extra virgin olive oil, soybean oil, and sunflower oil, among others, always remembering that they should not be exposed to high temperatures. Avoid animal fats (milk and dairy products, pork, red meat, chicken skin, etc.) and some vegetable fats like margarine and hydrogenated vegetable fat.
3. Avoid or limit the intake of alcoholic beverages. Men should not drink more than two drinks per day, while women should limit this consumption to one drink. Additionally, engage in moderate physical activity for at least 30 minutes, five times a week.
4. It is advisable for men, between 50 and 70 years old, during a medical consultation, to be informed about the need to investigate prostate cancer.
5. Men over 45 years old with a family history of father or brother with prostate cancer before age 60 should consult a doctor for prostate cancer screening.
6. Women, aged 40 or over, should have a clinical breast exam annually. In addition, all women between 50 and 69 years old should have a mammogram every two years. Women with a family history of breast cancer (mother, sister, daughter, etc., diagnosed before age 50), or those who have had ovarian cancer or cancer in one breast, at any age, should undergo clinical examination and mammography starting at 35 years of age, annually.
7. Women between 25 and 59 years old should undergo a gynecological preventive exam. After two consecutive normal exams, one exam should be performed every three years. For abnormal exams, follow medical advice.
8. It is recommended that women and men, aged 50 or over, undergo a fecal occult blood test annually (preferably), or every two years.
9. During leisure time, avoid prolonged sun exposure, between 10 AM and 4 PM, and always use adequate protection such as a hat, umbrella, and sunscreen. If you are exposed to the sun during your workday, wear a wide-brimmed hat, long-sleeved shirt, and long pants.
10. Perform daily oral hygiene (brushing) and visit the dentist regularly. |
Sources: INCA/MS, 2002. Prevention and Control of Cancer. Brazilian Journal of Cancerology, 2002, 48(3):317-332
INCA/MS, 2002. National Program for Prostate Cancer Control: consensus document
INCA/MS, 2003. Consensus for Breast Cancer Control
