The Medical Minute: Annual Pap tests -- simple and effective

January 26, 2005

By John Messmer
Penn State Family & Community Medicine
Penn State Milton S. Hershey Medical Center
Penn State College of Medicine

In 1943, physician George Papanicolaou published a study describing detection of cancer by the microscopic examination of cells from the vagina. It is interesting that the original study discussed detection of uterine cancer whereas the diagnostic test named for him, the Pap test, remains the premier screening examination for cancer of the cervix. Because January is cervical cancer awareness month, it's a good time to consider this important test.

More than 10,000 women are diagnosed with cervical cancer annually and almost 4,000 die, making it the sixth leading cause of cancer death in women, behind lung, breast, colon, uterine and ovarian cancer. The sad thing about this statistic is that the Pap test is an easy way to detect problems in an early stage before cancer actually develops. While many women do not get regular Pap tests due to lack of health insurance, many with coverage also avoid the exam.

Human Papilloma Virus (HPV), the family of viruses that cause warts, causes most, if not all, cervical cancer. Of the 100 or so members of the HPV family, only a handful causes cancer of the cervix, with the remainder causing warts elsewhere on the body. Viruses that cause common warts on the hands, face or feet do not cause cancer. Each strain infects a specific body part. Even though HPV causes genital warts, most women who contract HPV do not get cervical cancer.

All HPV viruses are contagious. The strains that cause cervical cancer are spread through sexual contact and can remain in the system for years before causing warts or cancer. A woman's risk of cervical cancer is higher the earlier she experiences intercourse for the first time, if she has multiple partners or if her partner has multiple partners. Birth control pills, which protect against ovarian and uterine cancer, do not protect against cervical cancer. In fact there is a statistical increase in cervical cancer in women using birth control pills, although this may not be related to the pill but to the number of sexual partners. Condoms protect against HIV, but not against HPV, because the condom may not cover all the virus-shedding warts. On the other hand, use of a diaphragm does seem to protect against HPV, either by the barrier itself or the spermicide used.

The risk of cervical cancer is higher in smokers, presumably because of the immune-suppressing effect of nicotine that is found in the vaginal mucus of smokers. Poor nutrition also increases the risk of cervical cancer, probably because it reduces immune-system function.

Women should begin scheduling Pap tests within three years of starting sexual intercourse, but no later than age 21. The test involves the physician taking a sample of the cells from the cervix from an internal exam. For decades, the test was done by touching the cervix with a wooden spatula device and a brush to lift a sample of cervical cells that would then be smeared across a microscope slide to be examined by a lab technician or pathologist using the technique developed by Papanicolaou. In recent years, doctors increasingly use a new technique in which the sample of cells is put into a special liquid. In the lab the cells are placed on the slide in a single layer, making them easier to examine and reducing the chance of missing an abnormal cell. It has the added feature of being able to test abnormal cells for infection with HPV.

An annual Pap has been the standard recommendation for years, but with the newer, liquid-based technology, it may be reasonable to extend this to every two years. Women who have had a hysterectomy no longer need to have a Pap sample, because the cervix is removed with the uterus. Menopause does not mean an end to Pap tests. A woman older than 70 who has had three normal Pap tests in a row and no abnormal Pap tests for the preceding 10 years can discontinue Pap exams as long as she does not have a weakened immune system or otherwise increase her risks for cervical cancer.

The Pap is just one part of the female gynecologic health exam, which includes breast exam and examination of all the reproductive organs. Women who do not need a Pap any longer should discuss what reproductive health exams their physician does recommend for them. Women without health insurance may look for local clinics that provide free or low-cost screening. Pennsylvania has a program to provide breast and cervical cancer screening for women under age 65 whose income is less than two and a half times the federal poverty level. Information is available at http://www.dpw.state.pa.us/family/breastcancerscreening/003671495.htm

Death from cervical cancer has dropped 70 percent in the last 40 years, largely because of Pap screening. Cervical cancer is preventable. Perhaps a female health exam is not something women look forward to, but it is effective, and it should be a priority for all women.

(Media Contacts)

Last Updated March 19, 2009