Cervical Cancer Screening – How Often Do I Need A Pap Smear?

Cervical cancer has decreased more than 50% in the past 30 years because of widespread screening with cervical cytology, “The Pap”. Our knowledge about the natural history of cervical cancer and cervical dysplasia (it’s precursor) have improved dramatically. The technique for doing the Pap smear has also changed and improved. Ninety percent of Pap smears are now done with liquid based cytology which can also check for Human Papilloma Virus (HPV). Because of these changes, cervical cancer screening guidelines also changed in December, 2009.

Cervical cancer screening should now start at age 21. Young adolescents commonly acquire HPV after initiation of intercourse. Cervical dysplasia develops in susceptible individuals due to infection with high risk types of HPV. Most adolescents will clear the infection in 1-2 years without developing dysplasia or cancer. Even if dysplasia occurs, most will regress spontaneously over several years. In addition, the risk of cancer before age 21 is very small, less than 0.1%. Treatment for cervical dysplasia can increase the risk of problems in pregnancy. Because the treatment can cause future problems and the dysplasia is likely to spontaneously resolve, the age for first Pap was increased to age 21 from earlier ages.

Cervical cancer screening is recommended every 2 years in women aged 21-29 years . Women 30 and older with 3 consecutive negative Pap tests may be screened every 3 years. In women 30-64 years of age screened in a large study in the US, 0.019% developed severe dysplasia in 3 years and no cancers developed. There are some exceptions: Women who are immunosuppressed, who have HIV, who were exposed to DES in utero, or who were treated for dysplasia or cancer in the past should be screened annually. Women with HIV should be screened twice in the first year and then annually.

Most cervical cancer is seen in women who have not been screened or were screened very infrequently. Cervical cancer peaks in the mid 40’s and then decreases. The American Cancer Society recommends stopping Pap smears in low risk women at age 70. The U.S. Preventative Services Task Force uses age 65. However women with multiple partners, previous abnormalities or high risk factors should continue to be screened.

Women who have had a hysterectomy with removal of the cervix for benign reasons, may usually discontinue Pap smear screening. Women with a history of high grade dysplasia or cancer can develop recurrent disease at the vaginal cuff and should continue screening.

Combined testing using the Pap smear and HPV DNA test can be used for screening in women over 30. Negative results on both tests confers a very low risk of developing moderate or severe dysplasia. In a European study, the risk of developing severe dysplasia over 3 years was 0.51% with Pap alone and 0.12% with Pap and HPV tests which were negative. HPV testing may not be covered by insurance or may be subject to your deductible. If you have questions, ask your physician to review your Pap history and discuss your options for cervical cancer screening.