The prognostic importance of metastatic site in men with metastatic castration-resistant prostate cancer.

The presence of visceral metastases is adversely prognostic in men with metastatic castration-resistant prostate cancer (mCRPC), but the prognostic impact of the site of visceral metastasis is unclear. Men with mCRPC in the TAX 327 phase 3 trial receiving docetaxel or mitoxantrone every 3 wk or weekly docetaxel, each with prednisone, were analyzed retrospectively to study the impact of the site of visceral metastasis on overall survival (OS). Patients were assessed for OS by site of metastases: liver with or without other sites, lung with or without bone or lymph nodes, bone plus lymph nodes, bone only, and lymph nodes only. Cox proportional hazards regression, adjusted for treatment and stratification factors, was performed. Men with liver metastases with or without other metastases had shorter median OS (10.0 mo; 95% confidence interval [CI], 5.4-11.5) than men with lung metastases with or without bone or nodal metastases (median OS: 14.4 mo; 95% CI, 11.5-22.4). Men with lymph node-only disease had the best median OS (26.7 mo; 95% CI, 22.3-34.2), followed by men with bone-only metastases (median OS: 19.0 mo; 95% CI, 18.2-20.7) and bone-plus-node disease (median OS: 15.7 mo; 95% CI, 14.4-17.2). Thus, pattern of spread including site of visceral metastasis confers a differential prognostic impact. These data require validation and may inform trial design and therapy.