Updated By: LatestGKGS Desk
Cancer: Introduction, Causes of Cancer, Risk Factors
Cancer: Internal and external risk factors which cause cancer
Cancer is caused by accumulated damage to genes. Such changes may be due to chance or to exposure to a cancer-causing substance.
The substances that cause cancer are called carcinogens. A carcinogen may be a chemical substance, such as certain molecules in tobacco smoke. The cause of cancer may be environmental agents, viral or genetic factors.
Cancer-causing factors related to work and living environments include:
- asbestos fibers
- tar and pitch
- polynuclear hydrocarbons (e.g. benzopyrene)
- Some metal compounds
- Some plastic chemicals (e.g. Vinyl chloride)
Bacteria and viruses can cause cancer:
- Helicobacter pylori (H. pylori, which causes gastritis)
- HBV, HCV (hepatitis viruses that cause hepatitis)
- HPV (human papillomavirus, papillomavirus, which causes changes eg. Cervical cells)
- EBV (Epstein-Barr virus, the herpes virus that causes inflammation of the throat lymphoid)
Radiation can cause cancer:
- ionizing radiation (e.g. X-ray radiation, soil radon)
- non-ionised radiation (the sun’s ultraviolet radiation)
Some drugs may increase the risk of cancer:
- certain antineoplastic agents
- certain hormones
- medicines that cause immune deficiency
