Cervical Cancer Screening: VICC Explains Changes in Recommended Guidelines
November 23, 2009
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As recently as the 1940s, cervical cancer was once among the most common cancers among women and a leading cause of cancer death. Thanks to the development in the 1950s of the Pap test, which tests cells from the cervix for pre-cancerous or cancerous changes, the incidence of cervical cancer and death rates have dropped dramatically.
Today, cervical cancer is the 14th most common cancer among women; 11,000 new cases will be diagnosed in the United States during 2009, and about 4,000 women are expected to die from the disease, according to the American Cancer Society. More recently, it has become clear that infection with the human papillomavirus (HPV) is the cause of cervical cancer, and vaccines have been developed to help prevent these infections, which should reduce the risk of developing cervical cancer over the next decade.
On Nov. 20, 2009, the American College of Obstetrics and Gynecology (ACOG) released new guidelines for cervical cancer screening. Howard Jones, M.D., Chair of the Department of Obstetrics and Gynecology at Vanderbilt School of Medicine and leader of the gynecologic oncology team at Vanderbilt-Ingram Cancer Center, answers common questions about the new guidelines.
Q. What are the new guidelines and how do they differ from previous recommendations?
A. Under the new guidelines from ACOG, women are advised to get their first Pap test at age 21. Previously, we recommended that women start cervical cancer screenings three years after becoming sexually active or at age 21, whichever came first. They recommend that women ages 21-30 should have a Pap test once every two years, rather than annually. And women 30 and older who have had three consecutive negative tests can be screened once every three years. The recommendations for older women have remained the same – after 10 years of normal Pap results and three or more negative results in a row, women can reasonably stop having Pap tests at 65 or 70.
Q. Why did ACOG change their recommendations?
A. I want to stress the fact that there is very good clinical evidence that these new guidelines will not result in a decreased effectiveness of cervical cancer screening or “missing” any women with cervical cancer.
These new recommendations reflect a better understanding of cervical cancer that we have learned over the past 10 years or more. Cervical cancer develops very slowly through a series of precancerous changes in the cervix. This very slow progression gives us ample time to detect the abnormal changes leading up to cancer and manage these abnormalities at a precancerous or very early stage. We now know that cervical cancer is caused by infection with HPV. This is a very common infection that many women’s immune system can fight off over time without any lasting harmful effects. In addition, technology has improved in recent years and now allows us to screen women with more sensitive tests that can be done less frequently with as good or even better results.
Although HPV infection rates do tend to be high in sexually active teen-agers, these young women are likely to fight off an HPV infection on their own, resolving minor Pap abnormalities without any active treatment. The National Cancer Database shows that cervical cancer is rarely diagnosed in women 21 or younger. On the other hand, treating HPV-caused cervical abnormalities can cause damage to the cervix, which, in turn, can put those young women at higher risk of premature delivery years down the road. So we want to avoid unnecessary diagnostic evaluation and treatment in these young women.
Q. What do these new guidelines say about vaccination against HPV?
A. The new guidelines do not address HPV vaccination. HPV vaccination, which is recommended for girls and women ages 11-26, is expected to reduce the overall number of cervical cancer cases and abnormal Pap tests over time. However, because the vaccines do not target all strains of HPV, all women should follow the recommendations for regular Pap tests, even those who have been vaccinated.
Q. There was a lot of controversy about recently announced changes in recommendations for breast cancer screening with mammography. Is that the same in this case?
A. No. I do not think these recommendations will be controversial. Most gynecologists have known about the improved screening technology and our increased understanding about the reversible development of the HPV-related precancerous changes in the cervix, so these guidelines make sense.
It is a coincidence that these recommendations were issued the same week that the U.S. Preventive Health Services Task Force issued new recommendations about screening mammography. There is a lot of controversy about when to begin screening mammography among cancer-related and professional organizations. (See our Q&A on the mammography issue). That is not the case for cervical cancer screening.
Q. Are there any downsides to delaying cervical cancer screening or waiting longer between Pap tests?
A. The studies that ACOG cites in its recommendations indicate that a longer interval between screenings will not lead to more cases of cervical cancer. Even today, most cases of cervical cancer are found in women who have not had regular Pap tests. We need to continue to emphasize the importance of Pap testing for all women.
We do not know how “getting a pass” for a year or two between recommended Pap tests might impact the frequency of women’s visits to their gynecologist and how that might affect their overall health. Many women, especially in their 20s and 30s, use their GYN as their primary care physician. We want to remind women that there are many other reasons besides undergoing a Pap test to have an annual “well woman” visits with a gynecologist.