Washington, DC -- Women should have their first cervical cancer screening at age 21 and can be rescreened less frequently than previously recommended, according to newly revised evidence-based guidelines issued today by The American College of Obstetricians and Gynecologists (ACOG) and published in the December issue of Obstetrics & Gynecology. Most women younger than 30 should undergo cervical screening once every two years instead of annually, and those age 30 and older can be rescreened once every three years.
Cervical cancer rates have fallen more than 50% in the past 30 years in the US due to the widespread use of the Pap test. The incidence of cervical cancer fell from 14.8 per 100,000 women in 1975 to 6.5 per 100,000 women in 2006. The American Cancer Society estimates that there will be 11,270 new cases of cervical cancer and 4,070 deaths from it in the US in 2009. The majority of deaths from cervical cancer in the US are among women who are screened infrequently or not at all. Cervical cancer is a slow growing cancer caused by certain strains of the human papillomavirus (HPV), an extremely common sexually transmitted disease among women and men. HPV also causes genital and anal warts, as well as oral and anal cancer.
"The tradition of doing a Pap test every year has not been supported by recent scientific evidence," says Alan G. Waxman, MD, at the University of New Mexico in Albuquerque and who headed the document developed by ACOG's Committee on Practice Bulletins-Gynecology. "A review of the evidence to date shows that screening at less frequent intervals prevents cervical cancer just as well, has decreased costs, and avoids unnecessary interventions that could be harmful."
ACOG now recommends that women from ages 21 to 30 be screened every two years instead of annually, using either the standard Pap or liquid-based cytology. Women age 30 and older who have had three consecutive negative cervical cytology test results may be screened once every three years with either the Pap or liquid-based cytology. Women with certain risk factors may need more frequent screening, including those who have HIV, are immunosuppressed, were exposed to diethylstilbestrol (DES) in utero, and have been treated for cervical intraepithelial neoplasia (CIN) 2, CIN 3, or cervical cancer.
Moving the baseline cervical screening to age 21 is a conservative approach to avoid unnecessary treatment of adolescents which can have economic, emotional, and future childbearing implications. ACOG previously recommended that cervical screening begin three years after first sexual intercourse or by age 21, whichever occurred first. Although the rate of HPV infection is high among sexually active adolescents, invasive cervical cancer is very rare in women under age 21. The immune system clears the HPV infection within one to two years among most adolescent women. Because the adolescent cervix is immature, there is a higher incidence of HPV-related precancerous lesions (called dysplasia). However, the large majority of cervical dysplasias in adolescents resolve on their own without treatment.
A significant increase in premature births has recently been documented among women who have been treated with excisional procedures for dysplasia. "Adolescents have most of their childbearing years ahead of them, so it's important to avoid unnecessary procedures that negatively affect the cervix," says Dr. Waxman. "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."
Routine cervical cytology testing should be discontinued in women (regardless of age) who have had a total hysterectomy (removal of the cervix along with the uterus) for noncancerous reasons, as long as they have no history of high-grade CIN.
ACOG's recommendations on the upper age limit for discontinuing cervical screening remain the same. It is reasonable to stop cervical cancer screening at age 65 or 70 among women who have three or more negative cytology results in a row and no abnormal test results in the past 10 years. ACOG also recommends that women who have been vaccinated against HPV should follow the same screening guidelines as unvaccinated women.
Practice Bulletin #109, "Cervical Cytology Screening," is published in the December 2009 issue of Obstetrics & Gynecology.