A recent study by the University of Southern California has linked a widespread virus, human cytomegalovirus (CMV), to the most common types of salivary gland cancer. Researchers have discovered that CMV re-activates a molecular pathway that normally turns off after birth, triggering unrestricted growth of virus-shedding tumors. This virus may also be implicated in other types of cancer.
What Is Cytomegalovirus?
The name comes from the characteristic large cells produced by infection with the virus. CMV is in the herpes virus family; all herpes viruses can lay dormant in the body for many years without producing symptoms. These viruses avoid detection by the immune system by creating chemicals that suppress infected cells’ immune reaction. Other human herpes viruses include Epstein-Barr, herpes simplex I and II (cold sores and genital herpes), and varicella zoster, which causes chicken pox in children and shingles in adults. Pregnant mothers infected with herpes viruses can pass the infection to the fetus, resulting in birth defects; cytomegalovirus is the most commonly transmitted. It is estimated that 50-80% of Americans are infected with CMV. Though it does not normally pose a threat to healthy adults, people with compromised immune systems – transplant patients, HIV-positive individuals, and newborn infants – are at risk for serious illness and death. A baby is at risk if a pregnant woman first contracts CMV during pregnancy.
The Cancer Connection
Cytomegalovirus shows a preference for the salivary glands, where it may eventually cause cancer. Most salivary gland tumors caused by CMV are painless and will go undetected until later stages of the disease. Along with human papillomavirus (HPV), cytomegalovirus is one of the 10 viruses known to cause cancer in humans. HPV is implicated in some oral cancers, especially those in young adults. Though oral cancer cases among older adults are declining, cases in adults under 40 are increasing, and most of these are due to HPV. Herpes viruses are among the most common sexually transmitted diseases.
Early detection is essential for patients with oral cancers. Patients undergoing treatment while cancer is in stage I have a 90% five-year survival rate. Since about two-thirds of oral cancers are not detected until stage II or III, the overall five-year survival rate for all patients is about 57% and has not significantly increased in decades. Dr. Ann Kania can screen for oral cancer in as little as five minutes during your visit. Schedule an appointment today by calling our Encinitas office at 760-642-0711. We serve patients in San Marcos, Carlsbad, Rancho Santa Fe, Del Mar, Carmel Valley, San Marcos, and the greater San Diego area.