Breast cancer is most commonly found in women 65 years or older. The increasing number of women in this age group means an absolute increase in new breast cancer cases. Because studies looking at the efficacy of mammography as a screening test for breast cancer have for the most part included younger women, recommendations for screening mammography in women at or older than age 65 are unclear. The nature of breast cancer in this population and the morbidity associated with treatment influence the potential value of screening. Analyzing cost-effectiveness and considering expected benefits, harms, and costs reduced the value of screening women under age 65, but the analysis of older women has been less clear. The U.S. Preventive Services Task Force (USPSTF) systematically reviewed published cost-analyses that evaluate breast cancer screening in women.
Life-years gained and costs per person were determined for different age groups. Screening for breast cancer after age 65 was compared with cessation of screening at that age. Ten studies were available that included data about older women. The results of the studies were fairly consistent, demonstrating that biennial screening after age 65 resulted in incremental costs of about $34,000 to $88,000 per life-year saved compared with stopping screening at age 65. It also was found to be cost-effective to screen women after age 65 if they previously had not been screened on a regular basis. The studies that looked specifically at comorbid conditions found that screening reduces breast cancer mortality in all but the sickest women.
This USPSTF review suggests that it is cost-effective to screen women 65 years and older for breast cancer every two years. However, screening is more costly among sicker women, who are likely to have a life expectancy similar to that of an 85-year-old woman (about five years).
Further analysis of women’s preferences, clarification of the natural history of tumors in older women, the value of diagnosing ductal carcinomas, potential needless distress from false-positive examinations, and the development of new adjuvant therapies need to be considered before concluding that the benefits of screening outweigh the harms.