November 8, 2002
Human papillomavirus (HPV) is the major cause of cervical cancer, which killed an estimated 4,400 women in the United States last year. Scientists have long suspected that other STDs could add to the risk. HSV-2 was a prime suspect, but studies had not come to any clear conclusion.
Jennifer Smith of the International Agency for Research on Cancer in Lyon, France, and colleagues around the world looked at specimens from more than 1,200 cervical cancer patients in several countries and compared them to samples from 1,100 other women of similar ages and circumstances. They analyzed their blood for evidence of HSV-2, HSV-1 (which causes cold sores), and chlamydia. They found 44 percent of the women with cancer had genital herpes as opposed to 25 percent of women without cancer. "HSV-2 infection may act in conjunction with HPV infection to increase the risk of invasive cervical carcinoma," they wrote.
However, Smith's IARC team found that when herpes infection was taken into account, a woman's sexual history, or that of her partner, was not such a big factor. Women who have sex more often or who start sexual activity earlier in life are more likely to have STDs, and this may account for the higher risk, the researchers said. Herpes can inflame the cervix, and the virus is also known to cause genetic changes in cells that could lead to cancer, Smith's team noted. But HPV is still by far the major cause of cancer. The researchers found DNA from HPV in more than 90 percent of the cancer patients.