Analysis of costs associated with administration of intravenous single-drug therapies in metastatic breast cancer in a U.S. population

Abstract

Background: An estimated $8.1 billion (in 2004 dollars) is spent annually on total health care costs for the treatment of breast cancer in the United States. Breast cancer has traditionally been treated with intravenous (IV) cancer therapies that entail not only the drug acquisition cost, but additional costs of personnel time, supplies, and equipment used in the preparation and administration of the IV drug. A systematic study of the costs of IV administration in the metastatic breast cancer (MBC) population has not been performed.

Objective: To assess the cost components, overall and by payer type and patient age group, for administering a single-agent IV breast cancer drug to women with MBC in the United States.

Methods: Women diagnosed with MBC (ICD-9-CM codes 174.XX and 196.XX-198.XX) reported any time between January 1, 2003, and May 31, 2006, and receiving single-agent IV breast cancer therapy (including intramuscular fulvestrant) during a visit were identified (using HCPCS and CPT codes) from an administrative claims database supporting 46 general/oncology clinics in the United States. Study drugs were either FDA-approved for breast cancer or recommended for use as preferred single agents per National Comprehensive Cancer Network (NCCN) clinical practice guidelines for breast cancer. Costs were estimated using the contracted allowed payment, which is the amount that the provider is eligible to receive from all parties, including payers and patients. Costs were measured using 2 approaches-average cost per IV-administration visit and average cost per patient per month (PPPM).

Results: Over the 41-month study period (through May 31, 2006), 46,273 patients had a breast cancer diagnosis, of which 8,533 (18.4%) were metastatic; 828 (9.7%) of these patients received 1 of 11 single-agent IV breast cancer drugs over 7,406 visits. Mean (SD) total payments across all drugs and cost components were $2,477 ($1,842) per visit and $4,966 ($3,841) PPPM, of which IV administration costs were 10.2% of per-visit and 11.4% of PPPM costs, and other drugs and services provided during IV administration were 30.8% of per-visit and 32.2% of PPPM costs. In both the per-visit and PPPM analyses, approximately 80% of costs for other drugs and services (approximately 25% of total treatment costs) were attributed to (a) antihypercalcemic agents (e.g., zoledronic acid: 6%-8% of total treatment cost), (b) colony-stimulating factors (CSFs) (e.g., pegfilgrastim, epoetin: 6%-7%), or (c) other anticancer agents being used off-label or for other conditions (e.g., bevacizumab, irinotecan, carboplatin, vincristine: 11%-12%). The remaining 20% of costs for other drugs and services (about 6% of total costs) were attributable primarily to antiemetic agents (e.g., palonosetron, granisetron) and miscellaneous or unclassified products. Non-protein-bound paclitaxel was the most commonly used IV therapy at a mean cost of $2,804 per visit, with IV administration accounting for $353 (12.6%) and other services accounting for $1,237 (44.1%) of total costs per visit. The second most commonly used IV therapy was trastuzumab at a mean cost of $2,526 per visit, with IV administration accounting for $214 (8.5%) and other services accounting for $336 (13.3%) of total costs per visit.

Conclusions: For patients being administered a single FDA-approved or NCCN-recommended IV drug for treatment of MBC, IV administration costs accounted for approximately 10%-11% of total cost, and the study drugs accounted for 56%-59%. Other drugs and services accounted for 31%-32%, most of which was attributable to antihypercalcemic agents, CSFs, anticancer drugs being used off-label for breast cancer or for other conditions, and antiemetic agents. Although costs of IV administration are 10%-11% of total IV chemotherapy costs for MBC and would clearly be avoided with the use of oral agents, the extent to which other costs would be avoided or incurred with use of oral agents is unknown and requires further research.