Posted by anderc8 on Tuesday, January 23, 2018 in News, TIPs 2017.

Written by Howard W. Jones III, M.D., and Ronald D. Alvarez, M.D., of the Department of Obstetrics and Gynecology

At the beginning of the 20th century, cervical cancer was the leading cause of death in women due to cancer in the U.S., primarily due to the fact that there was no effective screening strategy. The Pap smear was introduced for cervical cancer screening in the 1940s, and, since its adoption, deaths from cervical cancer have decreased by 90 percent in the United States over the past 70 years. “Get a Pap smear every year” was easy to remember, but a new understanding of how cervical cancer develops and new technology has resulted in updated screening guidelines. These guidelines can be confusing and we hope to clarify new screening recommendations with the following discussion.

What is a Pap test and how is it done?
Traditionally, the clinician scrapes cells from the surface of the cervix with a plastic or wooden spatula and spreads (or “smears” – thus Pap smear) them on a glass slide. The thin film of cells is then stained with a technique developed by Dr. Papanicolaou, and the slide is examined under a microscope where precancerous or cancerous cells can be identified. In some newer techniques, the cells are collected in a liquid vial and are spread on the slide by machine.

What is HPV and what does it have to do with cervical cancer?
HPV stands for human papilloma virus and high and intermediate risk HPV types have been demonstrated to cause cervical precancer (CIN) or cancer. HPV is a common sexually transmitted infection and studies show that about one third of young women between 21 and 30 will test positive for an HPV infection on any given day. However, like the common flu, most women will clear an HPV infection on their own with a normal immune response. Women with a persistent high and intermediate risk HPV infection have the highest risk of developing CIN or cancer. Development of cervical cancer is a slow process, progressing from HPV infection through CIN to cancer over a period of 5-10 years. At the present time, there is a vaccine (Gardasil 9) which can immunize young women against the most common types of HPV infection that cause CIN and cervical cancer.

What is an HPV test and how is that used in cervical cancer screening?
Testing for high and intermediate risk HPV is more sensitive than a Pap test, but because most women who test positive for HPV will clear this infection on their own and will never develop CIN or cervical cancer, HPV testing is usually done in conjunction with the less sensitive but more specific Pap test. Women with a positive HPV test but a negative Pap smear should be tested again in one year, and if they test positive for HPV a second time, further evaluation (colposcopy) is recommended.

Can HPV testing alone be used for cervical cancer screening without a Pap test?
In the past few years, several large international prospective trials have shown that HPV testing alone every five years (without an accompanying Pap test) is an effective strategy to screen for cervical cancer.  Though approved by the FDA in 2017, this strategy has yet to be widely adopted in the U.S.  due to concerns about patient compliance with the ‘every five years’ interval and the potential for more women with a normal cervix undergoing costly evaluations for transient HPV infection detected with HPV testing.

What are the current recommendations for cervical cancer screening?
In women with no gynecologic symptoms or previous cervical abnormalities, the current guidelines are as follows:

• No Pap smear screening before age 21
• Ages 21 – 30: Pap tests every 3 years
• Ages 30 – 65: Co-testing (Pap plus HPV testing) every 5 years OR primary HPV testing only every 3 – 5 years
• If no abnormalities: stop screening at age 65

Women who have had a hysterectomy for benign disease do not require further cervical cancer screening.

Conclusion
Nearly 13,000 women are expected to be diagnosed with cervical cancer annually in the U.S. The majority of these cases occur in women who have had sporadic or no screening for cervical cancer. It is important for young women to get a HPV vaccine, which is another effective strategy for preventing this debilitating and often deadly disease. Women should consult with your gynecologist about cervical cancer screening and HPV vaccination for yourself and with your pediatrician about HPV vaccination for your children.

In 2017, the Vanderbilt awarded a HPV Associated Cancers Consortium (HPV Active) Trans-Institutional Program to raise awareness and conduct educational programs about HPV associated cancers such as cervical cancer. Ongoing pilot projects are evaluating the epidemiology of HPV associated cancers in Tennessee and evaluating strategies to enhance HPV vaccination and to screen for other HPV associated cancers such as head and neck cancer. For more information about HPV Active and an upcoming HPV Infection and Associated Cancers Symposium, visit HPVACTIVE.org.