New HPV test sheds light on abnormal Pap results

by Heather Smith

Each year, one in 20 women is told that her Pap smear is "abnormal." Of these women, only 5-10% will actually have cervical cancer or cervical dysplasia, a precancerous condition that may progress to cancer if left untreated. Even though the vast majority of women with abnormal Pap test results are healthy, they will all be advised to have another Pap test three to six months later, to see if the results are normal.

"This method prolongs anxiety," says Tom Cox, MD, president of the American Social Health Association's Human Papillomavirus (HPV) Resource Center.

To make matters more stressful, if a woman's second Pap is abnormal, she will usually undergo a colposcopy (viewing of the cervix through a scope-like device) and biopsy (removal of cervical cells for testing). This creates unnecessary anxiety, since most women who undergo colposcopies are found to have a healthy cervix. In many cases, the cause of their abnormal Pap is not related to HPV the sexually transmitted disease linked to cervical cancer.

This anxiety may soon be alleviated. In February 2001, research from the National Cancer Institute (NCI) revealed that an HPV DNA test, conducted immediately after the first abnormal Pap test, recognized 96.3% of high-grade dysplasias serious enough to require immediate intervention.

Unlike the repeat Pap test six months later, the HPV DNA test can bring women answers right away.

Lead investigator Diane Solomon, MD, explains, "If the HPV test was negative there was a 99.5% probability that a woman did not have precancerous conditions. The test provides reassurance that there's no significant abnormality."

Even better, the HPV DNA test, used after a Pap test, is more accurate than a Pap test alone. The chance of missing high-grade dysplasia ranges from 15-20% with liquid Paps, and is approximately 30% with conventional Paps, says Dr. Cox. In comparison, the chance of the HPV DNA test missing high-grade disease in the NCI study was just under 4%.

The results of NCI's study have the potential to change how most gynecologists respond to abnormal Pap smears. Although more than 90 health insurance companies are now covering the cost of performing an HPV DNA test after an abnormal Pap, many gynecologists are still not using this method. In September 2001, a consensus meeting will be held to decide how abnormal Pap smears will be managed, in light of the NCI trial results and other research.

Women who have HPV and have been monitored for years for signs of cervical cancer may wonder what this new HPV DNA test means for them. HPV has both cancer-causing and non-cancer-causing strains, and the test is designed to detect cancer-causing strains only. However, most physicians will determine the strain of HPV at the time of the initial diagnosis.

Women concerned about passing HPV on to a female sexual partner (HPV does not pose a significant cancer risk for men) may also want to use the test to find out if they still have a cancer-causing strain of the virus. In most women, HPV infection simply disappears, but only a DNA test can confirm this.

Dr. Solomon reminds that it's important to discuss your options with your doctor and decide what's best for your situation.