The Annual Pap Isn’t Annual Any More
By: David A Fein, MD
No woman likes it but the annual Pap Smear has long been an unpleasant necessity. What many women don’t realize is that in recent years the guidelines for cervical cancer screening have changed. An annual Pap Smear is no longer recommended by the leading authorities.
According to the National Cancer Institute, there were more than 12,000 new cases of cervical cancer in 2013, resulting in about 4,000 deaths. More than 90% of cervical cancers are caused by prior infection with Human Papilloma Virus (HPV). This infection is sexually transmitted but very often produces little or no symptoms in women. There are numerous strains of HPV and most of them do not cause cancer.
A vaccine is now available which can protect against infection with some of the strains that pose the highest risk. But to be most effective, the vaccine must be given before infection occurs. A consensus is gradually emerging that men should also be vaccinated before they become sexually active. A higher percentage of men carry HPV and infection in men has been linked to penile and throat cancers. Vaccinating men for HPV will also help to lessen the risk of HPV infection in women.
The standard Pap Smear is used to screen for cervical cancer. By microscopically examining cells scraped from the lining of the cervix it is possible to detect cancer cells and pre-cancerous cells that indicate a high risk of future cervical cancers.
Most cervical cancers are slow growing. So, an annual Pap Smear may not offer a better outcome than less frequent testing. While there may be some delay in diagnosis with less frequent Pap Smears, it is unlikely that the cancer will have progressed enough to change the treatment or prognosis.
A separate test can be done at the same time the Pap Smear is done to detect the presence of HPV. Women who have no evidence of prior infection with HPV, or have only the low-risk strains of HPV present, are at much less likely to develop cervical cancer. In that case, the interval between Pap Smears can be extended.
The end result is that many women can forego annual Pap Smears and switch to a screening interval of every 3 to 5 years.
The US Preventive Services Task Force (USPSTF) and the American College of Obstetricians and Gynecologists currently recommends that women ages 21 to 65 have a Pap Smear every 3 years. The USPSTF guidelines go further and say that women ages 30 to 65 who do not have evidence of a high risk strain of HPV can go 5 years between a Pap Smear combined with HPV testing.
Women who have had a total hysterectomy, including removal of the cervix, and have never had an abnormal Pap Smear or gynecological cancer can discontinue Pap Smears entirely.
Women over the age of 65 who have never had an abnormal Pap Smear can also stop having Pap Smears done.
While an HPV test and Pap Smear are excellent screening tools for early detection of cervical cancer, they are not effective for other gynecologic cancers such as uterine and ovarian cancer. These cancers may be detectable as part of a routine pelvic examination by your doctor.
Pelvic ultrasound may also be able to detect uterine or ovarian cancers that have not yet started to cause symptoms. However, the evidence to date for screening for these cancers is much less compelling than screening for cervical cancer. Unfortunately, research efforts at early detection of these cancers has so far generally found that there was no significant improvement in long-term survival for these cancers but there was an increase in the number of surgeries for benign cysts and other non-cancerous conditions.