What are the main causes of cancer?

As an expert in the field of oncology, I can provide you with a comprehensive overview of the main causes of cancer. Cancer is a complex disease that can arise from a variety of factors, including both genetic and environmental influences. Here are the primary causes: 1. Gene mutations: These can be inherited from your parents or acquired during your lifetime. Acquired mutations are more common and can be caused by various factors such as those mentioned in your reference. 2. Tobacco use: Smoking is a leading cause of lung cancer and is associated with many other types of cancer due to the carcinogens in tobacco smoke. 3. Radiation: Exposure to certain types of radiation, such as ultraviolet (UV) rays from the sun or ionizing radiation from medical treatments or environmental sources, can increase the risk of cancer. 4. Viruses: Some viruses, like the human papillomavirus (HPV), hepatitis B and C (HBV, HCV), can cause changes in the body's cells that lead to cancer. 5. Carcinogens: Exposure to certain chemicals, such as those found in tobacco smoke, asbestos, and certain industrial chemicals, can lead to cancer. 6. Obesity: Being overweight or obese can increase the risk of several types of cancer, including breast, colorectal, and pancreatic cancers. 7. Hormones: Hormonal imbalances or long-term exposure to certain hormones, particularly estrogen and testosterone, can increase the risk of hormone-related cancers. 8. Chronic inflammation: Persistent inflammation in the body can lead to DNA damage and increase the risk of developing cancer. 9. Lack of exercise: A sedentary lifestyle can contribute to obesity and other health issues that increase the risk of cancer. 10. Alcohol consumption: Excessive alcohol intake is associated with an increased risk of several cancers, including liver, breast, and esophageal cancers. 11. Age: The risk of cancer increases as you get older because cells accumulate more mutations over time. 12. Environmental factors: Exposure to certain environmental pollutants and toxins can also contribute to cancer risk. 13. Diet: A diet high in processed and red meats and low in fruits and vegetables can increase cancer risk. 14. Inherited genetic factors: Some individuals have a family history that puts them at higher risk for specific types of cancer due to inherited mutations.

Gene mutations that occur after birth. Most gene mutations occur after you're born and aren't inherited. A number of forces can cause gene mutations, such as smoking, radiation, viruses, cancer-causing chemicals (carcinogens), obesity, hormones, chronic inflammation and a lack of exercise.