The cost of treatment-related adverse events in metastatic breast cancer therapy: Taxanes versus capecitabine.

Abstract

e17527 Background: Over 73,000 women annually experience new or recurrent metastatic breast cancer (mBC) in the U.S. Chemotherapy can prolong survival with mBC but adverse events (AEs) from chemotherapy are common, costly to manage and may lead to changes in clinical outcomes. We evaluated the difference in cost of treatment for taxane- (TAX) and capecitabine-based (CAP) treatments for mBC patients in the U.S. focusing on the incremental impact of AEs on the cost of care. Methods: A cohort of mBC patients diagnosed from 2008-2011 was identified from the Truven Marketscan® Database. Patients were grouped into chemotherapy categories of either TAX (paclitaxel or docetaxel) or CAP using claims data. Common chemo-related AEs were identified by ICD-9 codes. Healthcare costs were tabulated from a payer perspective, adjusted to 2011 U.S. dollars. To control for selection bias, propensity scores for treatment selection were calculated using age, diagnosis, health plan type, and renal or hepatic insufficiency as predictors. Generalized linear models estimated the cost of treatment by medication type and the presence/absence of AEs. Results: From 52 million subjects, we identified 13,474 mBC patients that met inclusion criteria. We identified 11,902 patients treated with TAX and 1,572 treated with CAP. At least one AE was experienced by 69% (S.D. = 0.46) of TAX users and 56% (S.D. = 0.50) of CAP users. The most common AEs were infection (39%), neutropenia (27%), and anemia (20%) for TAX users. CAP users most commonly experienced infection (36%), anemia (11%), and dyspnea (11%). Average incremental monthly costs were $3,082 and $6,793 for TAX and CAP patients with an AE compared to those who did not experience an AE, respectively. Costs increased by $1,358 for patients with 1-2 AEs (p=0.0002), $2,433 for 3-4 AEs (p<0.0001), and $5,294 for 5+ AEs (p<0.0001). Conclusions: Among community-treated patients, AEs are common in women with mBC receiving TAX and CAP based chemotherapy regimens. Persons experiencing these AEs have substantially higher healthcare costs which increase with the number of AE’s reported. Better management of AEs may represent an opportunity to significantly reduce costs and improve outcomes for women with mBC.