Treatment patterns and costs following metastatic breast cancer diagnosis in U.S. women: A SEER-Medicare analysis.

Abstract

150 Background: To use SEER-Medicare data to evaluate treatment (tx) patterns and health care costs in U.S. women with metastatic breast cancer (MBC). Methods: Key inclusion criteria included women diagnosed (dx) with breast cancer in 2001-2005 with 1) enrollment in Medicare 12 mo prior to dx through follow-up (2008) or death; 2) initial dx of “distant” disease or 2 indications of secondary malignancy >2 mo after initial dx; and 3) indication of tx with injectable hormonal, chemotherapy (chemo) or targeted/biologic therapies. Lines of tx were designated as: 1st-line if 1st agent (or agents, if on same day) after dx of MBC; new agents administered > 42 d after the previous agent are a new line, as well as an agent administered > 60 d after last dose of the same agent. Oral medication data were not available. Kaplan-Meier techniques estimated lifetime total health costs by partitioning data into 30-d intervals starting with MBC dx date and then summing the product of mean cost in each interval by the probability of survival to the start of the interval. Bootstrapping methods were used to generate 95% confidence intervals (CI). Results: The table lists the top 5 injectable tx for first, second, and third line, with associated mean lifetime costs. Conclusions: In this population, the injectable fulvestrant was the most commonly used first-line tx, with vinorelbine most frequently used in second- and third-line settings for MBC. Mean lifetime cost of MBC was $110,000. [Table: see text]