I am 64 years old. My doctor tells me that after next year, I will not need to have Pap smears. Can you explain?
Your Menopause Question: I am 64 years old. My doctor tells me that after next year, I will not need to have Pap smears. Can you explain?
Our Response: There is a great deal of confusion about what health benefit the Pap smear provides. Cancer risks for breast and colon cancer continue to rise as we get older, so why would age determine when the Pap smear is no longer needed? Currently, the standard recommendation of the American Society for Colposcopy and Cervical Pathology (ASCCP) is that if a woman has not had abnormal Pap smears in the past number of years*, and she is human papillomavirus (HPV) negative and at least 65 years of age, she may not need any more Pap smears during her lifetime. In general, patients who have undergone a complete hysterectomy do not require a Pap smear at all, unless they request it. So why should this aspect of a woman’s gynecologic examination be confusing?
The answer lies in its historical context and focuses on its anatomic significance.
First, a discussion on the anatomic significance. The Pap smear is taken from a small area on the face of the cervix where the columnar cells of the endometrium (lining of the uterus) meet the squamous cells originating from the outside of the cervix. This juncture of two cell lines is called the squamocolumnar junction. Under most circumstances, this localized sampling offers no information on the other components of the uterus itself, the ovaries, or the fallopian tubes; although rarely, abnormal cells from higher in the reproductive tract are picked up on a Pap smear.
Historically, the Pap smear has been the gold standard for over 100 years, dating back to 1916 when George Nicholas Papanicolaou first reported on the cervical cytology of guinea pigs. By 1928, he had developed a screening test to collect and analyze abnormal cells scraped from the human cervix (DeMay, 2005). Debate persisted over many years between those who favored tissue biopsies of the cervix and those who promoted merely sampling the cells from the surface of the cervix. However, science marches on. In 1925, Hans Hinselmann invented the colposcope to detect early invasive cervical disease. In 1928, Walter Schiller proposed Lugol’s (iodine) solution to detect abnormal areas on the cervix. The speed with which this progress in cervical cancer detection has been made is amazing, given that cancer has been present in humans throughout history.
However, it was the discovery of human papilloma virus (HPV) infection that transformed the science of cervical cancer. In 1983, after many years and investigative efforts, two strains of HPV, 16 and 18, were linked to cervical cancer. Seven more strains of HPV became known as the “high-risk group,” although with a lower affiliation to cervical cancer (Durst, 1983). Today, there is an ongoing debate as to whether HPV or cervical cell sampling should be the method of choice for ruling out cervical cancer risk. At present, cervical cell sampling is the standard, and HPV is the backup.
Is there any risk of cervical cancer if HPV is negative? The answer is possibly, since adenocarcinoma of the cervix may not be identified by HPV. In one study of 131 patients with cervical adenocarcinoma taken from the Swedish Cancer Registry, HPV was present in 89% of women under 40 years of age, but in only 43% of women over the age of 60 (Anderson, 2001).
*This is known as adequate prior screening, which can be defined as three consecutive negative cytology results or two consecutive negative co-testing results within ten years before stopping screening, with the most recent test occurring within five years.
More confusing, while it is written that persistent HPV may take as long as ten to 20 years to develop into cancer, a longitudinal study from Brazil followed 2,404 women who were tested every four to six months for eight years (Schlecht, 2003). Of that group, initially, 173 had atypical cells of undetermined significance (ASCUS), 118 had mild dysplasia, and 24 had marked dysplasia. Patients with abnormal Pap smears but with no HPV progressed more slowly than those who were positive for HPV over that eight-year period, yet half of the women who began with only mild dysplasia regressed to normal or ASCUS.
To conclude, if someone is persistently negative for HPV and cervical cell sampling, the risk of cervical cancer after age 65 is extremely low. Can this be a categorical statement? Not really. Exposure with new partners, even in independent/dependent nursing homes, carries some unknown risk.
Medical issues can never be compared to a light switch, as either on or off. Cervical cancer detection offers a good example of how thoughtful analysis will always be an essential part of medical science.
James Woods |