An oncology perspective on the benefits and cost of combined androgen blockade in advanced prostate cancer.

OBJECTIVES

To provide context in oncology for the significance of the benefits and cost of combined androgen blockade (CAB) in the treatment of advanced prostate cancer.

METHODS

Canadian drug costs for the survival benefit with CAB in advanced prostate cancer were compared with the costs of benefit with new treatments in advanced non-small-cell lung cancer (NSCLC), metastatic colorectal cancer, and metastatic breast cancer. Clinical toxicities were also compared.

RESULTS

The survival benefit with CAB in advanced prostate cancer appears to be approximately 3 months. The survival benefit with the addition of vinorelbine to cisplatin for the treatment of advanced NSCLC is approximately 2 months, and the survival benefit with the addition of irinotecan to fluorouracil (and leucovorin) for the treatment of metastatic colorectal cancer is approximately 2 to 3 months. The survival benefit with anastrozole or exemestane in advanced breast cancer, or with the addition of trastuzumab to standard chemotherapy in metastatic breast cancer that overexpresses human epidermal growth factor receptor 2 (HER2), is approximately 4 to 5 months. The calculated cost per month of survival benefit with bicalutamide in CAB for prostate cancer is 437 US dollars to 1107 US dollars. The cost per month of survival benefit with vinorelbine for NSCLC is 1241 US dollars and with irinotecan for colorectal cancer is 6812 to 11,214 US dollars. The calculated cost per month of survival benefit with anastrozole for breast cancer is 170 US dollars, for exemestane is 185 US dollars, and the cost per month with the addition of trastuzumab is 5230 US dollars. Vinorelbine and irinotecan are associated with severe grade 3 or 4 clinical toxicities, and an increased frequency of heart failure has been observed when trastuzumab is added to anthracyclines. Anastrozole, exemestane and nonsteroidal antiandrogens are associated with mild to moderate side effects.

CONCLUSIONS

The advantages offered by CAB (including the cost per month of survival benefit and minimal associated clinical toxicities) are comparable to the reported advantages of new treatments for other common cancers such as NSCLC, colorectal cancer, and breast cancer.