Prognostic significance of the presence of intraductal carcinoma of the prostate and bone metastasis in needle biopsy for prostate carcinoma patients with Grade Group 5.

Intraductal carcinoma of the prostate (IDC-P) and bone metastasis have been both identified to associate with unfavorable clinical outcome of the prostate carcinoma (PCa). Our objective is to examine whether IDC-P or bone metastasis at diagnostic biopsies was associated with each other and whether they were linked with overall survival (OS) and cancer specific survival (CSS) of Grade Group 5 patients. We retrospectively selected the prostate biopsy specimens of 120 PCa patients with Grade Group 5 from Qilu Hospital of Shandong University between 2012 and 2016. There were 12 patients with IDC-P only, 52 patients with bone metastasis only and 10 patients with both IDC-P and bone metastasis. Overall, there was a significant correlation between the presences of the IDC-P and bone metastasis (P = 0.003). Kaplan-Meier survival analysis demonstrated that the presence of IDC-P and bone metastasis in diagnostic needle biopsy both conferred unfavorable CSS of Grade Group 5 patients. In addition, the presence of bone metastasis was a poor predictor of OS. Univariate and multivariate analysis revealed that bone metastasis was an independent prognostic factor for OS of Grade Group 5 patients, but IDC-P failed to be significant for either OS or CSS. Collectively, our study suggested that bone metastasis is an important prognostic factor and superior than the presence of the IDC-P for PCa patients with Grade Group 5.