Not your mother’s Pap smear

Cervical cancer screening update: Not your mother’s Pap smear

POSTED DECEMBER 08, 2016, 9:30 AMAndrea Chisholm, MD, Contributor

Source: www.health.harvard.edu

Confused about when to get your next Pap test? Anxious because your doctor said you don’t need another Pap for five years? Well, you are not alone.

For several decades, getting a yearly Pap test has been the standard for cervical cancer screening. Cervical cancer, which still kills about 4,000 women annually in the United States, is really a preventable disease. The goal of cervical cancer screening is to detect areas of significant precancerous cells in the cervix (cervical dysplasia) and treat them before they become invasive cervical cancer. Early detection is key and for a long time the Pap test — which looks for abnormal cells — was the only tool available to screen for cervical cancer. Women were encouraged to get one yearly.

Then along came the discovery that HPV or human papilloma virus plays a key role in the development of cervical cancer. Researchers have studied the biology of HPV and cervical dysplasia. We now know that certain strains of HPV increase the risk of developing cervical cancer. And we also have a good understanding of how long it takes for some types of cervical dysplasia to become cervical cancer. Based on this new knowledge, experts concluded that women were being overscreened with annual Pap smears and overtreated for abnormal cells that were unlikely to ever become cervical cancer. Doctors started testing for high-risk strains of HPV, and new screening guidelines reflect this knowledge. The current recommendations for cervical cancer screening in average-risk women in the United States include:

• start screening at age 21
• stop screening at age 65 (in low-risk women with no prior history of severe dysplasia)
• women age 21-30: Pap test every three years
• women age 30-65: Pap test every three years or co-testing (Pap and HPV) every five years.

New and better screening techniques thanks to HPV testing

Now newer research supports the belief that a woman’s HPV status is the strongest predictor of her risk for cervical cancer. Randomized control trials have shown that screening using HPV testing alone or in combination with a Pap test allows for earlier detection of severe dysplasia and offers better protection against cervical cancer than a Pap test alone. In fact, recent interim guideline updates offer the option of high-risk HPV testing alone every three years to replace the current screening options. Although testing for HPV has advanced cervical cancer screening, it has not yet advanced the experience of cancer screening for women. Unfortunately, the current method for HPV testing requires a speculum exam just like a Pap smear.

A recent study from the Netherlands published in BMJ continues to support this recommendation. Dr. Maaike Dijkstra and associates reported that women who have HPV are at a markedly increased risk of developing severe cervical dysplasia and cervical cancer compared to women who are HPV negative. They concluded that women with a negative HPV test have a very low risk for cervical cancer. Using that conclusion, they suggest that a woman over the age of 40 who is HPV negative may wait longer than five years between her Pap tests. It is important to note that this increased interval is not yet recommended in the U.S.

For sure, there have been many changes in how we screen for cervical cancer in the last few years and there are certainly more to come. Likely HPV testing will eventually be adopted as a way to assess cervical cancer risk, and screening intervals will be determined based on the result.

One thing is for sure, gone for good are the days of the annual Pap test. As hard as it may be to let go of old habits, there is good science to support these changes. But remember, it is still important to see your gynecologist every year, because there is more to your annual visit than just screening for cervical cancer.