Virus type predicts risky cancer return.

Virus type predicts risky cancer return

Women those cervical cancer tumors contain a certain strain of human papillomavirus (HPV) will more likely suffer cancer recurrence after surgery than women showing no hint of this HPV in their tumors. That preliminary finding adds credence to the notion that one type of HPV leads to a more aggressive cervical cancer. If confirmed, the research may help doctors identify cervical cancer patients who need further therapy.

Human papillomaviruses are DNA-containing viruses that commonly cause warts. While scientists have identified nearly 60 HPV types, they have implicated just a few in cervical cancer.

Joan Walker, Sharon P. Wilczynski, Jeffrey D. Bloss and colleagues at the University of California Irvine Medical Center in Orange studied 100 women treated for cervical cancer. The researchers extracted DNA from tumors removed during surgery and used DNA probes to distiguish between three HPV types that commonly infect cervical cancer cells. The team found 46 women had tumors containing a kind of HPV known as HPV-16, 16 women had tumors with HPV-18 and two women had tumors with HPV-31. The remaining 36 women had no discernible HPV in their tumors.

Of the 100 women, the researchers focused on 69 who had a less severe form of cancer that appears confined to the cervix. Typically doctors can get about an 85 percent cure rate by treating such women with primary therapy such as a radical hysterectomy -- removal of the uterus, cervix and nearby tissues. The California team's report in the November OBSTETRICS & GYNECOLOGY suggests HPV typing may pinpoint the 15 percent of women who might benefit from additional treatment, such as chemotherapy or radiation, to kill cancer cells that remain after surgery.

The research team found 45 percent of women with tumors containing HPV-18 had cancer recurrence during the 20-month post-surgey observation period as compared to just 16 percent of women with HPV-16 tumors and 15 percent of women with no detectable HPV in their tumors. The scientists did not find a statistically significant higher death rate among women with HPV-18 tumors, although they suggest longer studies may show these women have a greater risk of dying early compared with women whose tumors contain no HPV-18. The study results must be confirmed before doctors can use HPV typing to recommend additional cervical cancer therapy, which can cause serious side effects, says Wilczynski, now at the City of Hope National Medical Center in Duarte, Calif.

The study suggests HPV-18 causes a rapidly progressing type of cervical cancer -- one that may go undetected by the Pap test used to detect precancerous cervical cells. The researchers found 45 percent of women with HPV-18 tumors had three normal Pap tests in the three years preceding their cervical cancer diagnoses. Only 16 percent of women with HPV-16 tumors had similar histories. The scientists now are studying healthy women with HPV-18 infection to see if they will get cancer.