Hormone therapy commonly is used to treat metastatic, locally advanced, and localized prostate carcinoma. The objective of the current investigation was to determine, using the number-needed-to-treat (NNT) method, the effect of using hormone therapy to treat locally advanced disease, with consideration given to both the complications and the known advantages associated with hormone therapy.
A literature review was performed to determine 1) the absolute benefit, based on available clinical endpoints, associated with the addition of hormone therapy to external beam radiotherapy for locally advanced prostate carcinoma; 2) the incidence of side effects of short-term and long-term hormone therapy; and 3) the stepwise progression from biochemical failure to death. A model was constructed to estimate the complication/utility-adjusted survival detriment resulting from the side effects of short-term (≤ 6 months) and long-term (> 6 months) hormone therapy, and the absolute/unadjusted and complication-adjusted NNTs for the addition of short-term and long-term hormone therapy were computed. In all cases, the magnitudes and signs of the NNTs obtained were used to gauge the effect of hormone therapy.
The unadjusted NNTs were positive and in most cases had relatively small magnitudes (the greater the NNT, the smaller the benefit) for both short-term and long-term hormone therapy; these results were expected, and they suggested that there is a strong benefit associated with the use of hormones adjuvant to radiotherapy for locally advanced disease. Adjusted NNTs remained positive and had relatively small magnitudes even after the introduction into the analysis of complications of short-term and long-term hormone therapy. This finding, although weak with respect to the effect of short-term hormone therapy on cause-specific survival, remained robust over the range of values for utility impairment expected from short-term and long-term hormone therapy.
The benefits of short-term and long-term hormone therapy for locally advanced prostate carcinoma appear to be significant and to outweigh the associated side effects. Long-term therapy appears to be better than short-term therapy in terms of virtually all endpoints studied, even when the increased incidence of side effects is considered. The current investigation was successful in the use of the complication-adjusted NNT method for oncologic and radiotherapeutic scenarios in which the results of randomized trials could be summarized, adjusted for treatment toxicity, and individualized to a given patient. Cancer 2003. © 2003 American Cancer Society.