First-line treatment in senior adults with metastatic castration-resistant prostate cancer: A prospective international registry.

AIMS

To compare the efficacy and tolerability of taxane and nontaxane therapy in senior adults with chemonaïve metastatic castration-resistant prostate cancer (mCRPC), and examine the effect of patient health status on outcomes.

PATIENTS AND METHODS

Between 2009 and 2011, 333 patients aged≥70 years with mCRPC were enrolled in a prospective international registry. Patients were categorized as having received taxane-based or nontaxane therapy, and classified as fit, vulnerable, frail, or terminal, according to investigator judgement or International Society of Geriatric Oncology guidelines. Efficacy measures included overall survival (OS) and progression-free survival. Grade 3/4 toxicities were recorded. Predictors of OS were identified using multivariate Cox regression.

RESULTS

The proportions of fit/vulnerable/frail patients were 65%/14%/17% (International Society of Geriatric Oncology), and 39%/43%/17% (investigator). In single-factor analyses, taxane therapy improved OS (hazard ratio [95%CI] = 0.53 [0.30-0.93]; P = 0.027) and progression-free survival (hazard ratio [95% CI] = 0.55 [0.40-0.76]; P<0.001) vs. nontaxane therapy. Patients with frailty also benefited from taxane therapy (adapted regimen in 52%). In multivariate analysis, taxanes improved OS even with poor prognostic factors present (P = 0.017); age was unrelated to prognosis. Taxane therapy was well tolerated; most common grade 3/4 toxicities (taxane vs. nontaxane) were fatigue (17% vs. 4%), nausea/vomiting (14% vs. 5%) and neutropenia (10% vs. 1%).

CONCLUSIONS

The results of this nonrandomized, observational study suggest that first-line taxane therapy may benefit senior adults with mCRPC more than alternative therapies. Treatment decisions should not be based on chronological age.