Mammography before diagnosis among women age 80 years and older with breast cancer.

PURPOSE: Screening mammography guidelines for patients age 80 years and older are variable. We determined the effect of mammography use on stage at breast cancer diagnosis and survival among women of this age range. PATIENTS AND METHODS: We used the linked Surveillance, Epidemiology, and End Results-Medicare database to evaluate 12,358 women >or= 80 years of age diagnosed with breast cancer between 1996 and 2002. Patients were grouped according to number of mammograms during the 60 months before diagnosis: nonusers (0 mammograms), irregular users (one to two mammograms), and regular users (three or more mammograms). Effects of mammography on disease stage (I to IIa v IIb to IV) and survival were determined by logistic regression and Cox proportional hazards analyses.
RESULTS: Percentages of women with nonuse, irregular use, and regular use of mammography during the 5 years preceding diagnosis were 49%, 29%, and 22%, respectively. On multivariate analysis, patients were 0.37 times less likely to present with late-stage cancer for each mammogram obtained (odds ratio, 0.63; 95% CI, 0.63 to 0.67). Breast cancer-specific 5-year survival among nonusers was 82%, that among irregular users was 88%, and that among regular users was 94%. However, survival from causes other than breast cancer was also associated with mammography use, suggesting a bias for healthier patients to undergo mammography.
CONCLUSION: Regular mammography among women >or= 80 years of age was associated with earlier disease stage, although improved survival remains difficult to demonstrate. Health care providers should consider discussing the potential benefits of screening mammography with their older patients, particularly for those without significant comorbidity.