The U.S. Department of Health and Human Services in November 2016 issued its 14th Report on Carcinogens—an updated list of known cancer-causing substances. New to the list are five viruses, which join three others (hepatitis B and C and human papillomavirus, or HPV) already on it.
It’s important to note that the chance of developing cancer from most of these viruses is extremely rare. In addition, the chance of these viruses being transmitted through blood transfusions or organ transplantation is extraordinarily low due to the extensive screening processes in place.
Below is an overview of the complete list of viruses:
Human immunodeficiency virus (HIV) type 1 is primarily spread by unprotected sex and infected needles. The virus, which causes AIDS, increases the risk of several cancers, including non-Hodgkin and Hodgkin lymphomas, Kaposi sarcoma, and genital cancers.
Human T-cell lymphotropic virus type 1, a rare virus in the United States, can be spread through unprotected sex, infected needles or syringes, and organ transplants. It can increase the risk of a rare blood cancer that infects specific white blood cells called CD4.
Epstein-Barr virus (EBV), transmitted primarily through saliva, is known for causing mononucleosis (“mono”). It can increase the risk of certain lymphomas and nasopharyngeal (the area in the back of the nose near the throat) and stomach cancers.
Kaposi sarcoma–associated herpesvirus is often transmitted through saliva and can also be spread through sexual contact, and blood and organ transplants. It’s been linked to Kaposi sarcoma, a blood vessel cancer, and two rare lymphomas.
Merkel cell polyomavirus (MCV) is a common virus that lives on the skin and—rarely—leads to an uncommon skin cancer called Merkel cell carcinoma.
Hepatitis B can cause chronic liver infections that increase liver cancer risk. It’s typically spread through blood, bodily fluids, unprotected sex, and infected needles.
Hepatitis C, like hepatitis B, can cause liver inflammation leading to liver cancer. It is spread in the same ways.
Human papillomaviruses (HPVs), some of which are spread through unprotected sexual activity, can increase the risk of cervical, vaginal, vulvar, penile, anal, and mouth and throat cancers. Women ages 35 to 65 should get HPV and Pap tests detect the virus and precancerous cells. Smoking can increase risk.
Many of the viruses can be avoided by:
• Exercising safer sex practices by using condoms and reducing the number of sexual partners
• Not sharing drug paraphernalia, especially needles, with others
• Not sharing drinks, food, or personal items (like toothbrushes) with individuals infected with EBV
• Getting the hepatitis B vaccine, especially if you’re at high risk
• Practicing good hygiene to aid in the natural shedding of MCV from the skin
Read more about the increase in sexually transmitted diseases and how to prevent them.