Breast cancer poses a huge medical burden to the U.S. health-care system, and chemotherapy is an important contributor to cancer costs. This article examines the differences between breast cancer patients who received chemotherapy and those who did not in costs and survival by age, treatment, and axillary node status.
We studied a cohort of 23,110 node-positive and 31,572 node-negative women aged 65 years and older diagnosed with incident American Joint Committee on Cancer stage I, II, or IIIA breast cancer between January 1, 1991, and December 31, 2002, using Surveillance Epidemiology and End Results–Medicare data. Total treatment costs and costs associated with the use of chemotherapy were estimated by using the phase-of-care approach. The phase-specific costs were combined to estimate total Medicare payments for cancer care from diagnosis to death. Cox proportional hazard ratio of mortality was used to determine the effectiveness of adjuvant chemotherapy after adjusting for selected patient and tumor characteristics. We used propensity scores to minimize the bias associated with the receipt of adjuvant chemotherapy.
Regression-adjusted difference in the average lifetime cost estimates for all node-positive patients receiving chemotherapy was approximately $2438 and was significantly higher (P 0.05) than for patients not receiving chemotherapy. Mortality was significantly lower in node-positive and node-negative women aged 65 to 74 years receiving chemotherapy.
Decision makers can use cost and effectiveness estimates from this study to assess the relative value of chemotherapy in different age groups.