Does hormone treatment added to radiotherapy improve outcome in locally advanced prostate cancer?: meta-analysis of randomized trials.

BACKGROUND

To quantify the magnitude of benefit of the addition of hormone treatment (HT) to exclusive radiotherapy for locally advanced prostate cancer, a literature-based meta-analysis was conducted.

METHODS

Event-based relative risks (RR) with 95% confidence intervals (CIs) were derived through a random-effect model. Differences in primary (biochemical failure and clinical progression-free survival) and secondary outcomes (cancer-specific survival, overall survival [OS], recurrence patterns, and toxicity) were explored. Absolute differences and numbers of patients needed to treat (NNT) were calculated. A heterogeneity test, a metaregression analysis with clinical predictors of outcome, and a correlation analysis for surrogate endpoints were also performed.

RESULTS

Seven trials (4387 patients) were gathered. Hormone suppression significantly decreased both biochemical failure (RR, 0.76; 95% CI, 0.70-0.82; P<.0001) and clinical progression-free survival (RR, 0.81; 95% CI 0.71-0.93; P=.002), with absolute differences of 10% and 7.7%, respectively, which translates into 10 and 13 NNT. cancer-specific survival (RR, 0.76; 95% CI, 0.69-0.83; P<.0001) and OS (RR, 0.86; 95% CI, 0.80-0.93; P<.0001) were also significantly improved by the addition of HT, without significant heterogeneity, with absolute differences of 5.5% and 4.9%, respectively, which translates into 18 and 20 NNT. Local and distant relapse were significantly decreased by HT, by 36% and 28%, respectively, and no significant differences in toxicity were found. Primary and secondary efficacy outcomes were significantly correlated.

CONCLUSIONS

Hormone suppression plus radiotherapy significantly decreases recurrence and mortality of patients with localized prostate cancer, without affecting toxicity.