P1-08-07: Survival in US Women Following an Indication of Metastatic Breast Cancer Diagnosis and Chemotherapy Initiation: A SEER-Medicare Analysis.

Abstract

Abstract Objective: Use SEER-Medicare data to identify US women with metastatic breast cancer (MBC) treated (tx) with chemotherapy (CTX) and evaluate survival. Methods: Key inclusion criteria were women diagnosed (dx) with breast cancer (BC) in 2001–2005 with 1) Medicare enrollment 12 mo prior to dx through follow-up (2008) or death; 2) an indication of tx with CTX at any time after initial BC diagnosis (any stage). Dx of MBC between 2001–2006. MBC dx date was defined as the initial BC dx date if the patient had “distant” disease at entry into SEER or the date of first appearance of secondary malignancy in claims data (ICD9 codes 197.0−198.1, 198.3−198.7, 198.82−198.89) during follow up, at least 2 mo after initial dx. CTX date was defined as the date of first receipt of a CTX agent commonly used to treat BC after the MBC date. Data on oral medications (e.g., most hormone therapies, capecitabine) were not available. Kaplan-Meier survival analyses were performed to describe survival after MBC dx (patients were censored at end of follow-up). Survival was assessed both from the date of MBC and receipt of first intravenous (IV) chemo. Subgroup analyses were performed based on age, type of MBC dx and estrogen receptor (ER) status. Results: Patient demographics and survival are shown in the table. Conclusions: Despite recent advances in treatment options, median survival following a dx of MBC is less than two years, and is approximately 16 months after start of IV CTX. Survival is shorter for patients who develop MBC after an initial breast cancer dx compared to those with MBC at diagnosis, and for those with ERnegative tumors. In order to improve clinical outcomes, it is critical to pursue a better understanding of tumor biology and appropriate use of new agents. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-07.