Understanding why and how often a woman should have a PAP
by Caroline Garrett
For most women, as long as we can remember, we have been advised to get an annual PAP smear.
However, do most of us know the answer to common questions such as, what actually is a PAP smear, what does is test for and how often should it be done?
A papanicolaou test, often abbreviated PAP, is a screening test for precancerous and cancerous cells in the cervix. Most types, approximately 99.7%, of cervical cancers are caused by a virus known as human papilloma virus (HPV) and are not thought to be hereditary. Human papilloma virus is transmitted through sexual contact, thus most of the sexually active population will come in contact with HPV at some point in their life. Most encounters with HPV are cleared by the body without any symptoms.
For some, HPV may cause mild changes in cervical cells, known as “low-grade”, while the body is working on clearing the virus. If the body is unable to clear the virus, this can lead to continued changes in cervical cells that may eventually become cancerous. These high-risk changes, also known as “high-grade” take about 3-7 years to become cancer. When cervical cancer screenings are done at the proper intervals, low-grade changes can be identified early and high-grade changes can be treated promptly. Current recommendations are to start PAP screenings at age 21. Prior to age 21, most infections with HPV are cleared from the body without symptoms and no intervention is necessary. For women aged 21-29, screening is recommended with PAP test alone every 3 years. If any abnormalities are identified on testing, further HPV testing is often included and your provider will explain the results and when further testing or intervention is needed. Women aged 30-65 should have their PAP test with co-testing of HPV every 5 years. They may also have PAP testing alone every 3 years, but co-testing is the preferred recommendation.
Following age 65, PAP testing is not recommended as long as there is no personal history of moderate to severe abnormal cervical cells or cervical cancer. Plus, the woman has had three negative PAP tests in a row or two negative co-testing results in a row within the last 10 years with the most recent being within the last 5 years.
If a woman has had a hysterectomy, she may or may not need continued screening. If the hysterectomy was done for non-cancerous reasons and the cervix is absent then no further PAP testing would be recommended. However, if the woman has a history of abnormal cervical cells or cervical cancer and/or the cervix has not been removed then PAP screening would need to continue. Currently, the recommendation for those who are high risk post-hysterectomy will continue screening for 20 years post-surgery.
The above routine screening guidelines are recommendations only and do not apply to those who are at higher risk for cervical cancer. These include, women infected with human immunodeficiency virus (HIV), are immune compromised, who were exposed to diethylstilbestrol (DES) in utero, or have a history of cervical cancer; screening may be required more often.
