RESUMO
BACKGROUND: It has been estimated that more than $8 billion is spent annually on the management of breast cancer in the United States. The taxane chemotherapeutic agents are cornerstones in the treatment of breast cancer, yet no study has assessed whether the choice of a taxane affects the economic outcomes of metastatic breast cancer treatment. OBJECTIVE: To determine if differences exist in the medical cost of care in patients receiving taxane-based chemotherapy for metastatic breast cancer, and to compare the use of ancillary medications (for neutropenia, anemia, and nausea and vomiting) and their associated costs among taxanes. METHOD: We identified women with metastatic breast cancer based on diagnosis codes and the women's previous adjuvant chemotherapeutic regimens. Paid medical insurance claims were captured for the 24-month study period, from January 1, 2006, through December 31, 2007. The groups were determined according to the specific taxane administered. Total medical costs were captured from the date of first taxane administration to the end of data availability. Outpatient pharmacy costs were not available. A multivariate analysis was used to evaluate the total medical costs in each group. Median total medical costs per patient per month during the study period were adjusted using a multiple regression analysis. Utilization and cost of medications administered in the office or hospital for chemotherapy-induced adverse effects were captured and adjusted with Tobit models. RESULTS: Of the 2245 study participants, 1035 received docetaxel, 997 received generic paclitaxel, and 213 received nab-paclitaxel. On average, patients in the nab-paclitaxel group received more doses (9.6) than those in the generic paclitaxel (6.0) or docetaxel (4.8) groups. The multivariate analysis was robust, explaining 72% of the variability in total medical costs across the 3 taxane groups. Median per-patient per-month total medical costs for study participants were within approximately $800 of each other among the groups. Generic paclitaxel had the lowest total medical costs. The total costs for docetaxel and nab-paclitaxel were not significantly different. Nab-paclitaxel had the lowest utilization and lowest costs associated with colony-stimulating factors. The proportion of patients receiving erythropoiesis-stimulating agents was not significantly different among the 3 drugs, but the costs for these agents were significantly lower in patients receiving nab-paclitaxel than in those receiving docetaxel. Antiemetic use was highest in the docetaxel group, but the costs for antiemetics were not different among the 3 taxane groups. CONCLUSION: The differences in total medical costs among the 3 taxanes were modest. Total medical costs were lowest for patients receiving generic paclitaxel and comparable between the docetaxel and nab-paclitaxel groups. Patients taking nab-paclitaxel received more doses than patients taking the other taxanes. Nab-paclitaxel was associated with lower utilization and costs for colony-stimulating factors compared with generic paclitaxel and docetaxel.
