The costs of treating breast cancer in the US: a synthesis of published evidence.

Published estimates for the treatment costs of breast cancer vary widely in methodology, perspective, patient populations and time horizon. We systematically summarized and analysed the published literature on per-patient costs of breast cancer, and highlight the perspectives, populations studied, time horizons and future directions for cost studies in breast cancer. This review included 29 US cost-of-illness studies for breast cancer. The estimates of lifetime per-patient costs of breast cancer ranged from $US20 000 to $US100 000. Payer perspectives were popular, while disease stages I and II were emphasized. The costs of initial and terminal therapy were greater than continuing care on a per-unit time basis, but continuing care accounts for the largest share of lifetime cost due to the relatively long survival of breast cancer patients. Costs of different surgeries were relatively similar (breast-conserving surgery vs mastectomy) but, all else equal, significant costs ($US23 000-31 000) were observed for patients who received adjuvant chemotherapy compared with those who did not. Multiple studies confirmed that costs increased with increased stage of disease and costs decreased with increased age of diagnosis. The question remains whether or not lower costs for elderly patients are associated with lower quality of care. The patient, employer and societal perspectives were rarely presented. Experts in the field have recommended the societal perspective for US-based cost-effectiveness analyses. Most lifetime cost estimates were likely an underestimate for today's lifetime cost of treating breast cancer because of changes in practice patterns and improved survival. Further societal-based cost studies that differentiate costs by stage, age and treatment time (initial, continuing and terminal), and include the latest practice patterns would be valuable toward informing US-based cost-effectiveness studies for preventive as well as breast cancer treatment interventions.