December 2, 2009

New Guidelines on Pap Tests Draw from UCSF Expert's Findings

The American College of Obstetricians and Gynecologists (ACOG) is recommending less frequent cervical cancer screening for healthy women over age 30 and says women younger than 21 need not be screened at all.

George Sawaya

The Nov. 20 announcement came just four days after a federal task force released a controversial set of breast cancer screening guidelines, which conveyed a similar message: For most women, cancer screening starts too young and occurs more often than medically necessary. The mammogram guidelines have provoked outrage from radiologists, women, cancer groups and elected officials, who on Dec. 2 held the first congressional hearing on the recommendations issued by the U.S. Preventive Services Task Force. Both the breast and cervical cancer guidelines are part of a long-running debate about the risks and benefits of screening. While ACOG credits the widespread use of Pap tests with reducing the incidence of cervical cancer by more than half over the past 30 years, it concludes that annual screening is largely ineffective from both a cost and a health standpoint. Instead, the group recommends screening every two years for women age 21 to 29 and screening every three years for women 30 and older who have had three consecutive negative Pap test results. For at least one UCSF cancer researcher, this development is long overdue. In a 2003 study in The New England Journal of Medicine, George Sawaya, MD, analyzed 1.2 million screening result records from a nationwide early cancer detection program and found that extending the cervical cancer screening interval from one to three years would lead to an increase of three or fewer cancer cases per 100,000 women. “This is not a new story,” said Sawaya, an associate professor of obstetrics, gynecology and reproductive sciences. “Since 1988, there have been suggestions that women can be screened less often than annually. Of course, that information hasn’t really stuck, partly because there’s this mentality of, ‘Why would you ever want less of anything?’ when it comes to cancer screening.” However, he said, while frequent screening may make patients feel protected, it also causes them to “suffer exponentially all the slings and arrows for false-positive testing.” Sawaya’s years of work on the benefits and risks of screening helped inform ACOG’s recommendations and his published studies were referenced half a dozen times within the new guidelines. Sawaya commented on the new guidelines in an editorial appearing in the Nov. 25 issue of The New England Journal of Medicine. “Guidelines promoting a recommendation to do less are often viewed with suspicion; individual women may feel as if they are being asked to accept greater personal risk as part of an overall effort to contain costs and conserve resources,” he wrote. “Clinicians should inform women that the changes in the guidelines have not been prompted by financial considerations but by careful consideration of the estimated balance between benefits and harms. Women should be made aware that health recommendations are updated periodically as newer, more robust evidence becomes available.” Read his entire perspective here.

Big Shift For Young Women

In a Nov. 20 interview, Sawaya said he hadn’t yet heard of any controversy surrounding ACOG’s announcement, which he found somewhat surprising given the group’s significant departure from previous screening recommendations for women under 21. Explaining that shift, ACOG noted that while young sexually active women have a high rate of infection with HPV— a group of viruses that is usually harmless but may in some cases cause cervical cancer—they have extremely low rates of invasive cervical cancer: only 0.1 percent of cervical cancer cases occur in women under 21. In addition, abnormal Pap results often lead to a sequence of follow-up tests that can prove harmful, particularly for young women, the new guidelines warn. For example, recent studies have documented a significant increase in premature births in some women who had undergone cervical treatments for abnormal and possibly cancerous cells. “Adolescents have most of their childbearing years ahead of them, so it's important to avoid unnecessary procedures that negatively affect the cervix,” said Alan Waxman, MD, an obstetrician and gynecologist at the University of New Mexico in Albuquerque who led the panel that developed the new guidelines. “Screening for cervical cancer in adolescents only serves to increase their anxiety and has led to overuse of follow-up procedures for something that usually resolves on its own.” Women who have been vaccinated against the two most common cancer-causing strains of HPV should follow the same screening guidelines as unvaccinated women, ACOG recommends. The vaccine does not protect women against certain harmful HPV types. ACOG’s previous screening practice guidelines, published in 2003, said that women should receive their first Pap test three years after becoming sexually active, even if they were still in their teens. The earlier guidelines also recommended annual screening for women age 21 to 29, and it offered three options to women 30 and older: annual Pap tests; a Pap every two to three years after three consecutive normal tests; or a combination of a Pap and a second screening method, an HPV DNA test. For women who choose the combination testing option, or “co-testing,” the procedure should be repeated no more than once every three years, ACOG advised. While highly sensitive to cellular abnormalities, the current DNA tests for HPV have also demonstrated a high rate of false positives, which can lead to invasive and unnecessary follow-up treatment. ACOG’s position on co-testing has not changed under the new guidelines. The latest recommendations add a new element to the national dialogue that began Nov. 16, when the U.S. Preventive Services Task Force (USPSTF) released a recommendation against routine annual mammograms for women under 50 and said healthy women age 50 to 74 can undergo the screening every other year instead of annually. The advice was praised by some as a decisive move toward more personalized, risk-based care, but was harshly criticized by others, including breast cancer survivors, who called it unsubstantiated and even dangerous.

Big Shift For Young Women

Related Links: