Chemotherapy-related adverse events among breast cancer patients: A retrospective analysis of the SEER-Medicare database

Abstract

10634 Background: Systemic chemotherapy is a common treatment option for female breast cancer (BC) patients. Chemotherapeutic agents often cause myelosuppression events (MEs), which may be costly and severe. Methods: Women ≥ 65 years of age diagnosed with stage I - III breast cancer from 1/1/92–12/31/99 within The Surveillance, Epidemiology and End Results (SEER)-Medicare database were analyzed. Using our extensive previous work with this BC cohort, a retrospective cohort study was conducted to assess the incidence and costs of MEs in chemotherapy-treated BC patients. Chemotherapies were captured using HCPCS codes; hospitalizations related to ME events (identified with ICD-9 diagnosis codes for anemia, thrombocytopenia, or leukopenia) were detected anytime after index date (date of first BC diagnosis). Total inpatient charges after index date were calculated. Results: 31,748 female BC patients were identified, 17.6% of whom received chemotherapy during follow-up. The mean age for these patients was 75.6 years (SD = 6.6, Range: 66–107). ME-related hospitalizations were significantly more likely in chemotherapy than non-chemotherapy patients, with 12.1% and 1.8%, respectively [OR = 2.3 (2.0–2.5)]; anemia in 8.6% and 5.1%, respectively [OR = 1.8 (1.6–1.0)], thrombocytopenia in 2.0% and 0.7%, respectively [OR = 2.9 (2.3–3.7)], and leukopenia in 4.4% and 0.5%, respectively [OR = 9.7 (7.8–12.1)]. Chemotherapy patients had significantly higher inpatient charges than patients without chemotherapy. Among chemotherapy patients, significantly higher inpatient charges were found in those with MEs than without ($15,297 vs. $4,211, p < 0.0001). Conclusion: Chemotherapy-related MEs were common among Medicare BC patients and led to substantial hospital charge increases. No significant financial relationships to disclose.