Clinical Implications of Tumor Size and Local Extent of Primary Prostatic Lesions in Prostate Cancer Patients with Metastases: Value of Endorectal Magnetic Resonance Imaging in Patients with Metastases

ObjectivesTo investigate the clinical significance of local assessment by endorectal magnetic resonance imaging (MRI) in prostate cancer patients with metastases.MethodsThe local extent and tumor size were determined by endorectal MRI in 95 prostate cancer patients with metastases, and their clinical implications were assessed.ResultsThe maximum diameter and tumor volume significantly correlated with the local extent of disease but not with extent of disease (EOD) on bone scan. In univariate analyses, EOD, serum prostate-specific antigen level, serum alkaline phosphatase level, and hemoglobin level were significantly associated with disease-specific survival, whereas tumor size and local extent of primary lesions were not. In a multivariate analysis EOD on bone scan was a significant prognostic factor.ConclusionsTumor size and local extent of the primary lesion estimated by endorectal MRI were not associated with disease-specific survival. Assessment of the primary lesion by endorectal MRI is of limited value in predicting the prognosis of prostate cancer patients with metastases.