Improvement in Breast Cancer Outcomes Over Time: Are Older Women Missing Out?

Abstract

Purpose Women aged ≥ 75 years account for 40,000 breast cancers/yr and are the most rapidly growing demographic. Recent data demonstrated that breast cancer death rates in the US population are declining, but it is not known whether death rates have declined similarly for older and younger women. We examined the following two outcomes: the rate of breast cancer death in the general population and the risk of breast cancer death in newly diagnosed patients, and we compared change over time in these outcomes for older versus younger women. Methods By using data from National Vital Statistics Reports that spanned from 1990 to 2007, the yearly change in the age-specific rate of breast cancer death was characterized with linear regression. With the use of the Surveillance, Epidemiology, and End Results nine-registry cohort that spanned from 1980 to 1997, the yearly change in age-specific risk of breast cancer death was characterized by using competing-risks regression adjusted for race and stage. Results Relative to 1990, the rate of breast cancer death in the general population decreased by 2.5%/yr for women age 20 to 49 years, 2.1%/yr for women age 50 to 64 years, 2.0%/yr for women age 65 to 74 years, and 1.1%/yr for women age ≥ 75 years. From 1980 to 1997, the adjusted risk of breast cancer death in newly diagnosed patients decreased by 3.6%/yr for women age less than 75 years versus 1.3%/yr for women age ≥ 75 years (P < .001). Over this time interval, the 10-year absolute risk of breast cancer death decreased by 15.3% for women age 50 to 64 years (from 31.9% to 16.6%) but by only 7.5% (from 24.8% to 17.4%) for women age ≥ 75 years. Conclusion Breast cancer outcomes have preferentially improved in women age less than 75 years. Focused research is needed to improve outcomes in older women.