Cost-utility analysis of second-line hormonal therapy in advanced breast cancer: a comparison of two aromatase inhibitors to megestrol acetate

Randomized trials comparing the aromatase inhibitors, anastrozole and letro zole, to megestrol acetate (MA) in postmenopausal women with advanced breas t cancer demonstrated that both agents are better tolerated than MA with co mparable efficacy. In addition, one trial revealed that tumor response and time to treatment failure were significantly better with letrozole. Since o ncologists are faced with a choice between three agents with at least compa rable efficacy but different toxicity profiles and cost, a cost-utility ana lysis was conducted to quantify these differences and to determine if the n ew agents are more cost-effective than MA. In the absence of a randomized t hree-arm trial, a decision model was developed to simulate the most common therapeutic outcomes. The clinical data were obtained from an overview anal ysis of randomized trials. Total hospital resource consumption was collecte d from 87 patients with advanced disease that had failed second-line hormon al therapy. Utility estimates were obtained from interviewing a random samp le of 25 women from the general public and 25 female health care profession als using the Time 'Trade-Off technique. The model suggested a similar dura tion of quality-adjusted progression-free survival between drugs (letrozole 150 days, anastrozole 153 days and MA 146 days). Letrozole had an overall cost of Can$2949 per patient which was comparable to MA at Can$2966 per pat ient. In contrast, anastrozole was slightly more costly than MA at $Can3149 per patient, respectively. The analysis revealed that letrozole has compar able overall costs relative to MA while providing at least equivalent quali ty-adjusted progression-free survival. These outcomes were largely related to its higher tumor response rate, which translated to a lower proportion o f patients requiring chemotherapy. Anastrozole was slightly more costly tha n MA and did not demonstrate superiority in quality-adjusted progression-fr ee survival in this palliative setting. [(C) 2000 Lippincott Williams & Wil kins].