New Pap guidelines may miss aggressive cancer in young women, study reports

(HealthDay)—Recent changes to cervical cancer screening guidelines that recommend less stringent testing may result in a higher incidence of a particularly aggressive type of cervical cancer in young women, a new study suggests.

When the U.S. guidelines for cervical cancer screening were first changed in March 2012, the differences were clear-cut: Women could start getting cervical cancer screenings at a later age and an annual Pap test for everyone was being replaced with a longer interval between screenings—typically three to five years, as long as no abnormalities showed up in a test.

But the researchers found that the time from a first abnormal Pap test to a diagnosis of this fast-moving cancer, known as adenocarcinoma of the cervix, was 21 months in women under 30 and 29 months for women older than 30.

"Any time national guidelines are changed pretty dramatically, I think it's important to reassess areas that may have been weakened," said study author Dr. Lisa Barroilhet, an assistant professor of gynecologic oncology at the University of Wisconsin in Madison.

"I don't think the new guidelines will cause a rampant epidemic of adenocarcinomas, [but] it's important to think about how a cure is obtained, which often involves removing a significant portion of the cervix," Barroilhet said. "If you're in your teens or 20s, you're probably not through with childbearing yet."

Results of the study were released online March 7 and will appear in the April print issue of the journal Obstetrics and Gynecology.

Adenocarcinoma used to be a rarer cancer of the cervix than squamous cell cancers. But because cervical cancer screening is so good at catching squamous cell cancers, the rate of adenocarcinomas as a proportion of all cervical cancers has been increasing, Barroilhet said. The early form of this cancer is referred to as adenocarcinoma in situ.

Cervical cancers usually are detected through the use of the Pap screening test, which involves collecting cells from the cervix and checking them for any abnormalities. More recently, screening for the human papillomavirus (HPV) also has become part of some cervical cancer screens. The HPV virus is responsible for almost all cervical cancers, according to the U.S. National Cancer Institute.

In general, the new recommendations are:

• No screening for women under 21.
• Women between the ages of 21 and 29 should have a Pap test every three years.
• A Pap test every three years or a combination Pap test along with testing for HPV, for women between the ages of 30 and 65.
• Screening isn't recommended for women over 65 unless they have a higher risk of cervical cancer or if they haven't gotten regular screenings in the past.

The current study reviewed a decade of a cases of women diagnosed with adenocarcinoma in situ (AIS) at Brigham and Women's Hospital in Boston.

Of the 242 women who were diagnosed with AIS, 208 had shown an abnormality in their Pap test. For two-thirds of those women, their Pap test initially suggested squamous cell changes rather than AIS, according to the study.

Squamous cell cancers are much slower-moving cancers, Barroilhet said. For the women in the study who were eventually diagnosed with AIS, however, the time from their abnormal Pap test to a diagnosis of AIS was 29 months for women older than 30, and just 21 months for those aged 30 and younger.

Seventeen cases occurred in women under 21, and 16 of these women had abnormal Pap tests, according to the study.

Dr. Elizabeth Poyner, a gynecologic oncologist at Lenox Hill Hospital in New York City, said it's particularly important to find these cancers early in women of childbearing age, because the treatments that are necessary to save a woman's life may compromise her fertility.

Barroilhet said these findings need to be confirmed in a larger group of women, and with patients from more than just one hospital. She also said she didn't think the current screening guidelines need to be re-examined due to the new findings.

"I think our screening guidelines were developed thoughtfully and thoroughly," she said. But, she added, this study does show a potential weakness in the guidelines.

Poyner agreed. "This is something we need to have a conversation about," she said. "Will the new guidelines compromise our ability to find adenocarcinoma in situ? Only time will tell for sure, but this is something we need to be concerned about."

Barroilhet added that young women can take an important step to protect themselves by getting vaccinated against HPV. The vaccine is recommended at age 12 or 13, but is approved for use in females from the ages of 9 to 26.

"If you get your HPV vaccine, the Pap screen then becomes much less critical," Barroilhet said.

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