Viruses that Cause Cancer

Some viruses have been found to increase the risk of developing cancer. Known as oncogenic viruses, these viruses disrupt regular cell function and can cause unchecked cell proliferation, which can result in cancer. Comprehending these viruses and their effects can aid in early detection, prevention, and treatment plans.

How Viruses Cause Cancer (Viral Oncogenesis)

Viruses change the genetic material of host cells, which leads to cancer. Viral oncogenesis is the process that includes:

• Inserting viral DNA or RNA into host cells, disrupting normal cell regulation.
• Suppressing the immune response, allowing abnormal cells to proliferate.
• Triggering chronic inflammation, which increases the risk of mutations and cancer development.

Major Oncogenic Viruses in Humans

Human Papillomaviruses (HPVs) and Cancer

Human papillomavirus (HPV) infectionis one of the leading causes of virus-induced cancers, particularly cervical, anal, and throat cancers.

• High-risk HPV strains (HPV-16, HPV-18) are responsible for about 99% of cervical cancer cases.
• Transmission occurs through skin-to-skin contact, primarily sexual contact.
• HPV vaccines, such as Gardasil and Cervarix, can prevent infections and lower cancer risk.

Epstein-Barr Virus (EBV) and Cancer Risk

Epstein-Barr virus (EBV) is linked to several cancers, including:

• Nasopharyngeal carcinoma
• Hodgkin’s lymphoma
• Burkitt’s lymphoma

EBV spreads through saliva and remains dormant in B cells. It can reactivate under conditions of immune suppression, increasing cancer risk.

Human Immunodeficiency Virus (HIV) and Cancer

Human immunodeficiency virus (HIV) weakens the immune system, increasing susceptibility to other oncogenic viruses. Common HIV-associated cancers include:

• Kaposi’s sarcoma (caused by Human herpes virus 8 - HHV-8)
• Non-Hodgkin’s lymphoma
• Cervical cancer (due to HPV co-infection)

HIV does not directly cause cancer but impairs immune surveillance, allowing other viruses to promote tumor formation.

Human Herpes Virus 8 (HHV-8) and Kaposi’s Sarcoma

HHV-8 is primarily associated with Kaposi’s sarcoma, a rare cancer affecting blood vessels and often seen in immunocompromised individuals.

• Spread through saliva and sexual contact.
• Common in people with weakened immunity, such as HIV-positive individuals.

Human T-Lymphotropic Virus-1 (HTLV-1) and Leukemia

HTLV-1 is linked to adult T-cell leukemia/lymphoma (ATLL).

• Transmission occurs via blood, sexual contact, and breastfeeding.
• Most infected individuals remain asymptomatic, but some develop aggressive leukemia.

Hepatitis B and C Viruses: Liver Cancer Risks

Hepatitis B (HBV) and Hepatitis C (HCV)can cause chronic liver disease and significantly increase the risk of hepatocellular carcinoma (HCC).

Here is the information in a table format:

Preventing Virus-Related Cancers

Preventative measures can significantly reduce the risk of virus-induced cancers. These include:

• Vaccination:
  • HPV vaccine prevents cervical and throat cancers.
  • Hepatitis B vaccine lowers liver cancer risk.
• Safe Practices:
  • Practicing safe sex reduces the spread of HPV, HIV, and HTLV-1.
  • Avoiding shared needles prevents HCV and HBV transmission.
• Regular Screening:
  • Pap smears for early HPV detection.
  • Liver function tests for HBV and HCV patients.

Conclusion

It is easier to implement early interventions and preventative measures when one is aware of the viruses that cause cancer. Routine screenings, safe practices, and vaccination are essential in lowering the incidence of virus-induced malignancies worldwide. For screening and preventive care, speak with a healthcare professional if you believe you may have been exposed to oncogenic viruses.