Cost-Effectiveness of Trastuzumab as Adjuvant Therapy for Early Breast Cancer: A Systematic Review

Abstract

Objective: To identify published, original, cost-effectiveness analyses presenting cost/quality-adjusted life year (QALY) ratios for trastuzumab used as an adjuvant treatment for HER2-positive early breast cancer and to evaluate the quality of reporting the favorable cost-effectiveness ratios. Data Sources: The terms trastuzumab adjuvant therapy, cost-effectiveness, quality-adjusted, QALY, and early breast cancer were searched in MEDLINE, PubMed, Embase, and CancerLit, as well as in Cochrane economic evaluation and reference lists from 1998 to June 2008. Only English-language publications were eligible. Study Selection and Data Extraction: All published studies examining cost-effectiveness outcomes on the basis of modeling or clinical trials were included. Cost-effectiveness analysis that measured health effects in units other than QALY, life year gained, neoadjuvant data, reviews, and comments were excluded. Each study was assessed independently by 2 trained reviewers. Data Synthesis: Thirteen of the 239 articles identified met the inclusion criteria, with 23 cost-effectiveness ratios pertaining to treatment of early breast cancer. These ratios ranged from $5020/QALY to $134,610/QALY. Most studies reported favorable cost-effectiveness values (ie, below $50,000/QALY). About 84.6% were conducted using a Markov model based on data from clinical trials and 15.3% were analyzed by other economic or cost models; 84.6% reported sensitivity analysis, 11 studies (84.6%) clearly described a justification of selecting study design, and only 15.3% noted study limitations. All studies mentioned their perspective; 92.3% did not show the funding source. Methods of reporting costs, effectiveness, and time-horizons for disease states varied significantly. Nine (69.2%) studies used a discount rate of 3%, 3 studies used a discount rate of 5%, and 1 study used 3.5%. The mean quality of the studies was 4.43. Conclusions: Most studies presenting the frequently proposed threshold of QALY suggest that trastuzumab may be cost-effective for treatment of early breast cancer in a 1-year treatment regimen.