July 23, 2003 |
Most women who have undergone hysterectomy for non-cancerous diseases can forgo annual Pap smear exams, according to new research by physicians. The study found that even in the best conditions, women add only three weeks to their lives by having regular screenings. The cost of these screenings per year of life saved can run up to $12 million for more aggressive screening plans. It’s the first study to look at the value of Pap smear screenings for women who have had a hysterectomy.
From University of Michigan Health System :
Most women can skip Pap smears after hysterectomy
U-M researchers find no benefit to screenings for women without risk factors
ANN ARBOR, Mich. ? Most women who have undergone hysterectomy for non-cancerous diseases can forgo annual Pap smear exams, according to new research by University of Michigan Health System physicians.
The study, published in the July issue of the Journal of Lower Genital Tract Disease, found that even in the best conditions, women add only three weeks to their lives by having regular screenings. The cost of these screenings per year of life saved can run up to $12 million for more aggressive screening plans. It’s the first study to look at the value of Pap smear screenings for women who have had a hysterectomy.
“Everyone thinks more prevention is better. What we found is that just because you have a test available doesn’t mean you should use it. Some tests are not really going to lead to any benefit,” says lead study author Michael Fetters, M.D., M.P.H., M.A., assistant professor of Family Medicine at the U-M Medical School.
More than a third of American women will undergo hysterectomy by age 60, making it the second most common major surgical procedure performed in the United States, behind the Caesarian section. Women most often require the procedure for benign conditions such as abnormal bleeding or uterine fibroids. A hysterectomy removes a woman’s uterus, which usually includes the cervix.
Pap smear screenings have proven effective at detecting cervical cancer and have become a standard part of a woman’s annual health check-up. Traditionally, physicians have continued to perform the test in women who have had hysterectomies, even though they no longer have a cervix, believing it may help detect vaginal cancer or other abnormalities.
“Why are doctors doing Pap smears on women who don’t have a cervix? It doesn’t make sense. But it became the standard of care,” Fetters says. “There’s really no significant value to doing it as a screening test.”
Study authors used medical modeling to analyze different approaches to screening women after total hysterectomy. They looked at multiple screening strategies:
One screening at age 50.
One screening at age 50, followed by another screening at age 60.
Screenings once a year for three years, starting at age 50, followed by one screening every three years.
Screenings once a year for three years, starting at age 40, followed by one screening every three years.
Screening every three years after three consecutive normal tests is the standard used most often for women with an intact cervix, and has become the default screening strategy for women with total hysterectomy. The average age at which hysterectomy occurs is 40.
Researchers conducted a sensitivity analysis to determine the likelihood of individual women developing vaginal cancer, the life expectancy and the cost of performing the screenings. In some cases, data was weighted in a way to favor more screenings. For example, it’s not known how accurate vaginal smears are for detecting vaginal cancer. Researchers assumed it was as accurate as the test is for cervical cancer.
At best, the difference between no screening and any screening strategy was three weeks. For a one-time screening at age 50, that amounts to $143,875 per year of life gained. For the screenings every three years beginning at age 40, it costs $12.8 million per year of life gained. Generally, the guideline for cost-effective care is up to $100,000 per quality-adjusted life year based on accepted costs of kidney transplants in people with end-stage renal disease.
Aggressive screening is less effective at detecting vaginal cancer in women with total hysterectomy because the cancer spreads more easily. Cervical cancer can be caught in the early stages, because the cancer must travel through the uterus before it can reach other organs. Vaginal cancer spreads quickly into adjacent organs because the vaginal wall is so thin and other organs so close. This means the cancer becomes advanced much more quickly.
Vaginal cancer is a highest threat to women ages 50 to 70, although primary vaginal cancer is extremely rare, especially if other risk factors are not involved. But the study authors still recommend regular Pap smears for women whose hysterectomy was linked to cervical cancer or who have a history of human papillomavirus (HPV) infection, which is commonly associated with vaginal and cervical cancer.
“In a woman who has been married for years and has only one sexual partner, it’s appropriate to forgo Pap smears after hysterectomy. But if the woman’s risk factors for lower genital tract cancer change, all bets are off and she’ll need to be screened regularly,” says study co-author Richard Lieberman, M.D., clinical assistant professor in Pathology and Obstetrics and Gynecology at U-M Medical School. “The main risk factors associated with the development of precancerous and cancerous changes of the lower genital tract (cervix, vagina or vulva) include human papillomarivus infection and other sexually transmitted diseases, multiple sexual partners and alteration of immune status.”
In the past, physicians have typically continued with the Pap smears in women with total hysterectomies as a way of ensuring they seek yearly health maintenance exams. The Pap smear is a key part of a woman’s annual check-up. In its early life in the 1950s, major public health campaigns stressed the importance of women seeking a regular Pap smear for the prevention and detection of cervical cancer. The test was a huge factor in reducing the rates of women dying from cervical cancer.
For women with total hysterectomies, even if the Pap smear is not necessary, that annual trip to the doctor still is.
“The Pap smear was always one extra way of assuring women would come back for their annual exam,” Lieberman says. “After hysterectomy, women should still come in for a breast exam, mammogram, cholesterol check and other health maintenance issues. We just need to refocus our emphasis on patient education: You’re not coming in for your annual Pap test but for your health maintenance exam.”