10 cancers fueled by viruses
Oncoviruses operate by wreaking havoc with a cell’s life cycle. “In simple terms, our cells have switches, which tell the cells either to grow or die,” says Dr. Angel Rodriguez, an oncologist at Houston Methodist Hospital, where he’s the director of the Triple Negative Breast Cancer Clinic. “Viruses interfere with the ‘switch’ mechanism and, instead of dying off, a cell continues to grow uncontrollably.”
Because of its effect on cellular behavior, an oncovirus can indirectly pave the way for cancers to begin. However, says Rodriguez, medical evidence strongly suggests that certain viruses directly cause certain cancers.
Here are 10 cancers associated with a virus, and a to-do list that may help prevent getting them.
Throat cancer and HPV
Throat cancer, medically known as oropharyngeal cancer, is typically found deep in the throat near the vocal cords, says Rodriguez. It was the diagnosis for Michael Douglas, but the condition can affect women, too. Transmission of the human papillomavirus (HPV) is typically through oral contact, including oral contact with sexual organs that contain even a miniscule amount of HPV.
Precautions: For individuals with many sexual partners or who practice oral sex, condoms aren’t foolproof as protection, says Rodriguez. But the good news is that a recent medical study involving a vaccine (ASO4-adjuvanted HPV16/18) suggests the vaccine may protect women against oral HPV16 and HPV18 infection. “This study raises the hope that, by reducing this type of infection, the vaccine can also help lower the risk of throat cancer.”
Liver cancer and HCV
Hepatitis C virus (HCV) is the form of the hepatitis virus most closely associated with liver cancer in the United States. It reproduces and stimulates inflammation in the liver which, over time, can lead to liver damage and cancer, says Dr. Melanie Thomas, an oncologist and associate director of clinical investigations at Hollings Cancer Center at the Medical University of South Carolina. People are often exposed to HCV through blood transfusions or needle sharing, she says.
Precautions: The Centers for Disease Control and Prevention has recommended that people who received blood transfusions prior to 1992, when our country’s blood supply was not as carefully screened for HCV, get tested for HCV. Thomas, whose specialty is liver, gall bladder and bile duct cancers, and who founded CanLiv, a hepatobiliary cancer nonprofit, also advises individuals with HCV to eliminate alcohol consumption. “Damage to the liver, as a result of imbibing alcohol regularly, may include cirrhosis, which may increase cancer risk,” she says.
Burkitt lymphoma and EBV
Although Burkitt lymphoma is extremely prevalent in French Equatorial Africa, this cancer, tied to Epstein-Barr virus (EBV), is also found in the United States. This aggressive disease of the lymph nodes typically affects people who take immunosuppressant medications, generally after receiving an organ transplant, says Thomas.
Precautions: People who take immunosuppressants long-term are typically monitored by their physicians, says Thomas, but she adds that being proactive about medical status with one’s health-care provider is the best policy.
Vaginal and vulvar cancers and HPV
HPV also has been linked to cancer of the vagina (the birth canal) and, to a lesser extent, cancer of the vulva (the external part of a woman’s genitalia, including the labia), says Houston Methodist Hospital’s Rodriguez.
Precautions: He notes that, because vaginal cancer is relatively rare, and the discovery of the HPV vaccine is so recent, there hasn’t been research on the vaccine’s effect on vaginal cancer. In the case of vulvar cancer, because of the labia’s external location, women can easily check that area for physical changes and seek medical attention accordingly, he says.
Nasopharyngeal cancer and EBV
A rare cancer, nasopharyngeal carcinoma affects the upper part of the throat, behind the nose. People of Asian descent are at higher risk for this cancer and may opt for a blood test to determine whether they are infected with EBV, says Rodriguez.
Precautions: Unfortunately, he says, there are no preventative actions or lifestyle changes to help prevent this cancer.
Kaposi sarcoma and HIV
Kaposi sarcoma, tied to human immunodeficiency virus (HIV), causes abnormal tissue growth beneath the surface of the skin, or at other sites or in other organs of the body. “The type of HIV – a herpes-like virus – most associated with Kaposi sarcoma is HHV-8,” says Rodriguez, noting that a strong immune system can often fight this virus off. He underscores that not every person with HIV carries HHV-8. “However, if people infected with HIV develop Kaposi sarcoma, the presence of Kaposi is definitive that they have AIDS.”
Precautions: Because studies have linked transmission of HIV and HHV-8 to anal sex, Rodriguez advises limiting this type of sex and also the number of sexual partners.
Hodgkin lymphoma and EBV
Hodgkin lymphoma is a cancer of the lymph nodes, in which the virus disrupts the lymph cells’ ability to die off. Actor Michael C. Hall, from the television series “Dexter,” was diagnosed with the illness in 2010. About half of all cases are caused by EBV, says Rodriguez.
Precautions: Because most people who develop Hodgkin lymphoma, also known as Hodgkin’s disease, have no known risk factors, it’s difficult to advise on preventative measures or lifestyle changes, he says.
Adult T-cell leukemia and HTLV-1
Adult T-cell leukemia is a cancer that affects the blood or bone marrow. “The disease is associated with, but not always directly caused by the HTLV-1 virus -- human T-lymphotropic virus -- which is often transmitted through IV drug use,” says Dr. Gopal Chopra, a brain-cancer researcher who also specializes in neurosurgery. “These high-risk individuals’ compromised immune systems, which lessens their ability to fight infection, along with the increased risk the virus poses for contracting this type of leukemia, can be a deadly combination.”
Precautions: There’s no treatment or vaccine for HTLV-1, says Chopra, a co-founder of PINGMD, a secure patient-and-physician medical-communication app. Eliminating drug use involving needle sharing is the first step, he says, adding that people who shared needles in the past should ask their medical professional to test them for the virus.
Anal cancer and HPV
Not to be confused with colorectal cancer, anal cancer, the disease that affected actress Farrah Fawcett, affects the skin around the anus. Often associated with HPV, anal cancer is usually caused by anal sex, says Rodriguez. However, he notes, because of the proximity of the anus to the sexual organs, small amounts of HPV-containing material can find its way to the anus, even in the absence of anal sex.
Precautions: Rodriguez advises high-risk individuals – those with HIV or people who have had many sexual partners – to have a medical professional check for precancerous lesions with an anal pap smear. He notes that condoms are not a 100 percent guarantee against HPV transmission.