Final answer:
Viruses can contribute to cancer by introducing oncogenes or interfering with tumor suppressor genes, leading to uncontrolled cell growth. Approximately 15 percent of human cancers are related to viral infections. Vaccines against certain viruses can help prevent associated cancers, and virus-based treatments are also being explored.
Step-by-step explanation:
How Viruses Contribute to Cancer:
Certain viruses are known as oncogenic viruses and have the ability to cause cancer by disrupting the normal regulation of the host cell cycle. They can achieve this either by introducing genes known as oncogenes which promote uncontrolled cell growth or by interfering with genes that inhibit cell growth. Such oncogenic viruses include DNA or RNA viruses.
Examples of cancers associated with viral infections are:
- Cervical cancer, caused by human papillomavirus (HPV)
- Liver cancer, caused by hepatitis B virus
- T-cell leukemia, and various types of lymphoma
Additionally, vaccines are available for some of these viruses and can play a critical role in preventing the associated cancers by stimulating the immune response.
Viruses contribute to approximately 15 percent of all human cancers, and infectious agents like HPV, hepatitis viruses, and Epstein-Barr virus are the main culprits. Notably, Helicobacter pylori, a bacterium, can also cause gastric cancer through chronic infection.
Furthermore, the inherent cell-killing properties of viruses are being explored in clinical trials as potential treatments for cancer, targeting cancer cells with specific mutations or characteristics.