Main causes of cancer
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Genetic and Environmental Causes of Cancer
Cancer develops when abnormal cells grow uncontrollably and invade healthy tissues. The main causes of cancer can be grouped into genetic factors and environmental exposures. Genetic predisposition, such as inherited mutations, plays a role in some cancers, but most cases are linked to environmental and lifestyle factors 1789.
Lifestyle Factors: Tobacco, Diet, and Physical Inactivity
Tobacco use is one of the most significant causes of cancer, responsible for about one-third of all cancer deaths. Smoking greatly increases the risk of lung cancer and several other types of cancer 236. Other lifestyle factors, such as unhealthy diets (high in red and processed meats, low in fiber), obesity, physical inactivity, and alcohol consumption, also contribute to cancer risk 1368+1 MORE.
Environmental Exposures: Chemicals, Radiation, and Occupational Hazards
Exposure to certain chemicals, such as those found in some pharmaceuticals, wood dust, and specific herbs, can increase cancer risk. Radiation, including X-rays and ultraviolet (UV) rays from sunlight, is another well-established cause of cancer. Occupational exposures, such as working with carcinogenic substances, have historically been linked to higher cancer rates in certain jobs 3569.
Infections: Viruses, Bacteria, and Parasites
Infectious agents are responsible for nearly one in five cancers worldwide. Viruses such as human papillomavirus (HPV), hepatitis B and C, Epstein-Barr virus, and human herpesvirus 8 are linked to cancers of the cervix, liver, and lymphatic system. Bacterial infections, especially Helicobacter pylori, are strongly associated with stomach cancer. Some parasites and fungi are also recognized as cancer-causing agents 3469+1 MORE.
Genetic Mutations and Cancer Development
Cancer is fundamentally a genetic disease caused by mutations in genes that control cell growth and division. These mutations can be inherited (germline mutations) or acquired during a person’s lifetime (somatic mutations). Oncogenes and tumor suppressor genes are the main gene types involved in cancer development. Mutations in these genes can lead to uncontrolled cell growth 789.
Oxidative Stress and DNA Damage
Oxidative stress, caused by an imbalance between free radicals and antioxidants in the body, can damage DNA and contribute to cancer formation. Both internal processes and external exposures (like smoking and UV radiation) can increase oxidative stress, leading to mutations and cancer progression .
Conclusion
The main causes of cancer include a combination of genetic predisposition, lifestyle choices (such as tobacco use, diet, and physical inactivity), environmental exposures (chemicals and radiation), and infections from viruses, bacteria, and parasites. Understanding these risk factors is crucial for prevention, early detection, and effective management of cancer 1345+5 MORE.
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