What is Cancer?
Cancer is a group of diseases characterized by abnormal cell growth. Normally, cells grow in a controlled manner, but in cancer, they divide uncontrollably, forming tumors that invade nearby tissues and disrupt organ function.
Cancer cells can also spread through the bloodstream or lymphatic system to other parts of the body, a process known as metastasis.
The Global Burden of Cancer
14 million new cancer cases are diagnosed annually, with 8.2 million deaths related to the disease.
The number of new cases is expected to increase by 70% over the next two decades, reaching 22 million cases per year.
The most common cancers in men:
- Lung cancer
- Prostate cancer
- Colorectal cancer
- Stomach cancer
- Liver cancer
The most common cancers in women:
- Breast cancer
- Colorectal cancer
- Lung cancer
- Cervical cancer
- Stomach cancer
Certain cancers, such as colon, breast, and prostate cancer, are more common in developed countries due to obesity, poor diet, and lack of physical activity.
In developing countries, cancers linked to dietary habits and infections (e.g., liver, stomach, and esophageal cancer) are more prevalent.
Leading Causes of Cancer Deaths
- Lung cancer – 17.8% of all cancer deaths.
- Stomach cancer – 10.4%.
- Liver cancer – 8.8%.
Causes of Cancer
Cancer develops due to a combination of genetic, environmental, and lifestyle factors. While it is not contagious, certain viral infections can increase the risk.
Major Risk Factors
1. Tobacco Use
- Smoking accounts for 85% of lung cancer deaths.
- Smokers have a significantly higher risk of developing oral, laryngeal, esophageal, pancreatic, bladder, kidney, and cervical cancers.
- The risk decreases after quitting smoking, and continues to decline over time.
- Chewing tobacco increases the risk of oral and throat cancer.
2. Diet & Obesity
High-fat diets increase the risk of breast, colon, uterine, and prostate cancer.
Obesity is linked to cancers of the prostate, pancreas, uterus, colon, ovary, and breast cancer in older women.
A diet rich in fruits and vegetables reduces the risk of cancers affecting the pharynx, larynx, lungs, stomach, and colon.
3. Sunlight Exposure
Ultraviolet (UV) radiation from the sun, sunlamps, and tanning beds increases the risk of skin cancer.
4. Alcohol Consumption
Heavy drinking raises the risk of mouth, throat, esophagus, larynx, and liver cancer.
Some studies suggest a link between alcohol consumption and breast cancer.
5. Radiation Exposure
High doses of medical X-rays increase cancer risk.
However, the radiation from diagnostic X-rays is minimal and generally outweighed by the benefits.
6. Workplace Hazards
Exposure to asbestos, nickel, cadmium, uranium, radon, vinyl chloride, benzene, and pesticides increases cancer risk.
7. Hormone Replacement Therapy (HRT)
Long-term estrogen therapy increases the risk of uterine and breast cancer.
8. Chronic Infections
Viruses, bacteria, and parasites contribute to 9% of cancers in developed nations and 23% in developing countries.
9. Genetic Factors
Some cancers (e.g., breast, ovarian, and colon cancer) are more common in families.
It is unclear whether this is due to genetics, shared environmental factors, or chance.
Cancer Prevention Strategies
1. Primary Prevention (Reducing Risk Factors)
Health education and awareness campaigns. Anti-smoking programs to reduce tobacco use.
Improved diet:
- Low-fat, high-fiber diets with fresh fruits and vegetables.
- Reduced red meat consumption.
- Encouraging regular exercise and maintaining a healthy weight.
- Limiting alcohol intake.
- Minimizing exposure to environmental carcinogens.
- Avoiding unnecessary medical X-rays.
- Using sun protection (sunscreen, protective clothing).
- Promoting workplace safety.
- Using low-estrogen contraceptives when necessary.
2. Secondary Prevention (Early Detection & Treatment)
Identifying high-risk groups based on:
- Family history.
- Occupation.
- Environmental exposure.
- Screening & early detection methods:
- Self-examinations (breast, testicular, and skin cancer).
- Clinical check-ups for early tumor detection.
- Mass screening for precancerous conditions.
Medical tests:
- Mammography (breast cancer).
- Endoscopy (gastrointestinal cancers).
- Microscopic examination of suspicious tissue.
3. Tertiary Prevention (Treatment & Rehabilitation)
- Palliative care for advanced cancer patients.
- Managing complications to improve quality of life.
- Physical, psychological, and social rehabilitation.
Final Thoughts
Cancer remains a global health challenge, but prevention, early detection, and effective treatment can significantly reduce its impact. By making healthy lifestyle choices, staying informed, and undergoing regular screenings, individuals can lower their risk and improve their chances of early diagnosis and successful treatment.
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