Pap smears and mammography screening should be targeted at healthy older women and avoided by older women in poor health, in whom risks of screening outweigh potential benefits, according to a study by UCSF researchers at the San Francisco Veterans Affairs Medical Center (SFVAMC).
The study, published in the May issue of Annals of Internal Medicine, examines how age and health status affect screening mammography and Pap smear rates among women over the age of 70.
“The good news is that the rates of screening mammography and Pap smears have really increased in healthy older women,” says lead researcher Louise C. Walter, MD, UCSF assistant professor of medicine in the geriatrics division at SFVAMC. “The problem is that there is still a population of very healthy older women who are not being screened who should be. And there’s a population of very sick elderly women who are getting screened when they shouldn’t be.”
Walter and her colleagues analyzed data from 4,792 women age 70 or older who took part in the 2001 California Health Interview Survey. The women rated their overall health and functioning using a standard scale.
Of the women surveyed, 78 percent reported a recent mammogram and 77 percent said they had recently had a Pap smear. Overall screening rates decreased with advancing age. However, women with the worst health indicators continued to get screened as much or more than those considered the healthiest.
For women with life expectancies of less than five years, the potential risks of screening tests may greatly outweigh the potential benefits, Walter says. Such risks include unnecessary tests due to false-positive results, identification and treatment of clinically insignificant disease and psychological distress.
“You have to balance the potential risk of developing a symptomatic cancer versus the risk of having side effects from the procedure,” says Walter.
While organizations such as the American Cancer Society recommend that screening be based on a patient’s health status, not solely on age, the study revealed that significant numbers of healthy older women are not being screened.
“Why are we seeing these particular patterns? It may be because people are using screening checklists based on age cut-offs,” says Walter. “I don’t think the ‘one shoe fits all’ approach works in geriatrics. Basing screening decisions on age alone, without considering health status, is not optimal.”
The VA/UCSF study also revealed that of the 1,994 women in the study who had undergone a hysterectomy for a non-malignant condition, such as bleeding or fibroid cysts, 39 percent reported having a Pap smear within a year of the survey. “The majority of these women don’t have a cervix anymore,” say Walter. “These women should have been informed that without a cervix they were not at risk for cervical cancer and so did not need the test.”
Walter says women need to be educated about the value of these tests. “We need to come up with better ways to help people understand what the benefits and risks of screenings are. We also need to look into how to better communicate with people on how to make an informed decision.”
The study was funded by a grant from the Veterans Administration Research Career Development Award from the Division of Health Services Research and Development. Co-authors of the study are Karla Lindquist, MS, a senior statistician in geriatrics at UCSF and the SFVAMC, and Kenneth Covinsky, MD, MPH, UCSF associate professor of medicine and a SFVAMC staff physician.