According to the American Cancer Society (ACS) breast cancer is the most common cancer among women, other than skin cancer , and the second leading cause of cancer death in women, after lung cancer . The ACS also estimates that approximately 12,200 new cases of invasive cervical cancer will be diagnosed in the US in 2003, and approximately 4,100 women will die from this disease.

Fortunately, early detection tests such as screening mammography for breast cancer, and the Pap test for cervical cancer, have reduced mortality from these diseases in women under age 70. But, do these same benefits apply equally to elderly women?

Recent research seems to say no. Although the use of mammography and Pap smears is lower among older women than it is among younger women, the number of elderly women receiving these tests is on the rise. However, the impact of these tests appears to be of limited benefit. This leaves some clinicians wondering whether such widespread, general screening in women 70 and older is a misdirected use of health care funds that might be better utilized in higher-risk, underserved populations.

To address this issue, a group of researchers set out to determine just how often older women were receiving screening mammograms and Pap tests and who, among these women, was most likely to receive these tests. The results of their study, published in the November/December 2003 issue of The Annals of Family Medicine found that the use of screening mammography and Pap smears in elderly women is increasing, despite a lack of evidence of its value in these patients.

About the study

The researchers examined data from 5,942 women between the ages of 50 and 61 who were enrolled in the Health and Retirement Study (HRS) and 4,543 women age 70 or older who were enrolled in the Asset and Health Dynamics Among the Oldest Old (AHEAD) study. The data was collected over six years (1994-2000). All of the women in the study were interviewed regarding their health behaviors, disease and disability history, and medical care usage, particularly whether they had received either a screening mammography or a Pap test over the most recent two-year period.

The findings

The researchers found that 70% to 80% of women between the ages of 50 and 64 had received mammograms within the past two years and that approximately 75% of these women had undergone a Pap smear during the same period. Among women between the ages of 85 to 90 years, the percentage of mammograms and Pap smears dropped to 40% and 25%, respectively. However, the overall rate of screening in all these age groups increased from 1995 to 2000.

The researchers also found that those women who were at the lowest risk for either breast or cervical cancer (married women with higher education levels, higher income, and non-smokers who participated in regular vigorous exercise) were the most likely to be screened, whereas those who were at the highest risk were the least likely to receive regular screening.

How does this affect you?

The researchers concluded that although the use of mammography and Pap tests for screening declines as women get older, its use, even in the oldest age groups, has been increasing. Their concern is that this increase may not be justified as there is currently no scientific evidence showing its benefit in older women.

While a great deal of research has demonstrated the importance of cancer screening in younger and middle-aged women, this is not the case in older women. One reason may be a greater risk of mortality from other illnesses and a diminishing importance in identifying asymptomatic cancers, particularly when these women may not live long enough to benefit from the treatment of their cancer. Indeed, based on the results of this study, researchers estimate that as many as 240 healthy 80-year-old women would need to undergo mammogram screening in order to prevent a single death from breast cancer.

The researchers estimate that in the year 2000 alone, 4.6 million women over the age of 70 had mammograms and 3.7 million had Pap smears. Using an estimated cost of $100 per mammogram and $14.60 per Pap smear (a conservative estimate), mammogram screening and cervical cancer screening in older women cost approximately $460 million and $47 million, respectively, not including follow-up costs for further evaluation and clinical management.

This is not to say that all breast and cervical cancer screening in elderly women is unnecessary. Otherwise healthy patients with no evidence of other serious illness may indeed benefit from continued, albeit less frequent, screening. However, clearly some patients are being subjected to unnecessary procedures. The findings of this study sound hauntingly familiar to an almost identical debate going on over PSA screening for prostate cancer in elderly men.

While withholding potentially beneficial services to people simply because they’re old is a dangerous precedent to set, it is important to remain mindful of the fact that these screening tests are not without risk. Positive results routinely lead to more testing and subsequent treatments that may not be well tolerated by frail elderly patients. Studies like this one remind us that sometimes the best thing we can do for older men and women is to simply leave them alone.