3.30岁以上妇女，如果没有CIN 2 或者 CIN 3，不是艾滋病病毒感染者，不处于免疫抑制状态（例如免疫病或者器官移植后患者，需要长期服用免疫抑制剂），没有子宫内的DES暴露史（通常指，本人的母亲在妊娠期曾经接受过不适当的雌激素治疗病史），而且连续三次筛查结果都正常，可以将筛查的间隔改为每三年一次。
Laurie Barclay, MD
November 20, 2009 — First cervical cancer screening should be at age 21 years, and rescreening can be less frequent than previously recommended, according to newly revised evidence-based guidelines issued by the American College of Obstetricians and Gynecologists (ACOG). The ACOG\"s Committee on Practice Bulletins—Gynecology was posted online November 20 and will appear in the December print issue of Obstetrics & Gynecology.
Less Frequent Screening
The revised recommendations now call for cervical screening once every 2 years vs annually for most women younger than 30 years and once every 3 years for most women 30 years and older.
"The tradition of doing a Pap [Papanicolau] test every year has not been supported by recent scientific evidence," lead author Alan G. Waxman, MD, from the University of New Mexico in Albuquerque, said in a news release. "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."
Either the standard Pap test or liquid-based cytology is suitable for all cervical cancer screening. Instead of annual screening, the ACOG now recommends that women aged 21 to 30 years who not at high risk be screened every 2 years and that women 30 years and older may be screened once every 3 years if they have had 3 consecutive negative cervical cytology test results.
Risk factors that may indicate the need for more frequent screening include HIV infection; immunosuppression; diethylstilbestrol (DES) exposure in utero; and treatment of cervical intraepithelial neoplasia (CIN) 2, CIN 3, or cervical cancer.
ACOG\"s earlier recommendation was to begin cervical cancer screening 3 years after first sexual intercourse or by age 21 years, whichever occurred first. To avoid economic, emotional, and future childbearing implications of unnecessary treatment of adolescents, ACOG has now moved the baseline cervical cancer screening to age 21 years.
The rationale is that invasive cervical cancer is very rare in women younger than 21 years, although the rate of human papillomavirus (HPV) infection is high among sexually active adolescents, because the immune system in most adolescent women clears the HPV infection within 1 to 2 years. In addition, adolescents have a higher incidence of HPV-related precancerous dysplasia because the cervix is immature, but most of these lesions resolve spontaneously without treatment.
Women treated with excisional procedures for dysplasia have recently been shown to have a significant increase in premature births.
"Adolescents have most of their childbearing years ahead of them, so it\"s important to avoid unnecessary procedures that negatively affect the cervix," Dr. Waxman said. "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."
Regardless of age, women who have had a total hysterectomy for benign conditions and who have no history of high-grade CIN should discontinue cervical cancer screening.
The upper age limit for discontinuing cervical screening remains the same in the revised ACOG\"s guidelines, which recommend stopping cervical cancer screening at age 65 or 70 years for women who have at least 3 consecutive negative cytology results and no abnormal test results in the previous 10 years.
Women vaccinated against HPV should follow the same screening guidelines as unvaccinated women, according to the revised guidelines.
Specific ACOG recommendations in the updated guidelines, based on good and consistent scientific evidence (level A), are as follows:
Cervical cancer screening should begin at age 21 years and should be avoided at younger ages, when it may result in unnecessary and harmful workup and treatment in women who are at very low risk for cancer.
For women aged 21 to 29 years, cervical cytology screening is recommended every 2 years.
The interval between cervical cytology examinations may be extended to every 3 years for women at least aged 30 years who have had 3 consecutive negative cervical cytology screening test results and who have no history of CIN 2 or CIN 3, HIV infection, immunocompromised state, or DES exposure in utero.
Acceptable screening techniques are liquid-based and conventional cervical cytology methods.
Routine cytology testing should be discontinued in women who have had a total hysterectomy for benign conditions and who have no history of high-grade CIN.
For women older than 30 years, an appropriate screening test is cytology combined with HPV DNA testing. When both these test results are negative in a low-risk woman 30 years or older, rescreening should be performed no sooner than 3 years later.
Specific ACOG recommendations in the updated guidelines, based on limited and inconsistent scientific evidence (level B), are as follows:
Sexually active women younger than 21 years should be counselled and tested for sexually transmitted infections and should be counselled regarding safe sex and contraception. Cervical cytology testing is not necessary, and speculum examination need not be performed in asymptomatic women.
Cervical cancer screening can be discontinued between the ages of 65 and 70 years in women who have 3 or more consecutive negative cytology test results and no abnormal test results in the past 10 years because cervical cancer develops slowly, and risk factors decrease with age.
Women previously treated for CIN 2, CIN 3, or cancer remain at risk for persistent or recurrent disease for at least 20 years after treatment and after initial posttreatment surveillance. This group should therefore continue to be screened annually for at least 20 years.
Even after the period of posttreatment surveillance, screening should continue for women status post hysterectomy with removal of the cervix who have a history of CIN 2 or CIN 3, or in whom a negative history cannot be documented. In this patient group, there are no good data to support or refute discontinuing screening.
Revised ACOG recommendations, based primarily on consensus and expert opinion (level C), are as follows:
Physicians should inform their patients that annual gynecologic examinations may still be appropriate regardless of the frequency of cervical cytology screening, even if cervical screening is not performed at each visit.
Women who were vaccinated against HPV-16 and HPV-18 should follow the same screening guidelines as nonvaccinated women.
A proposed performance measure recommended by ACOG is the percentage of women aged 21 to 29 years who have received a Pap test within the past 2 years.
Obstet Gynecol. Published online November 20, 2009.