Expression of androgen receptor, somatostatin receptor subtypes, aurora kinase A, and interleukin-6 in prostate cancer before androgen ablation.

e16508 Background: Neuroendocrine differentiation (NED) in prostate cancer (PC) can be detected by immunohistochemistry as single cells in conventional adenocarcinoma. NEPC is a poor-recognized late presentation of hormone refractory subtype of PC AR-negative. NEPC correlates with poor prognosis, tumor progression during androgen-deprivation therapy and frequent visceral metastases. Aurora kinase A (AURKA) and Interleukin-6 (IL-6) cooperate to induce NED. The aim of this study was to correlate the expression of somatostatin receptor (SSTR) 1- 2- 3- 4- 5 subtypes, AURKA and IL-6 in primary PC with NED pattern before androgen ablation and OS. Methods: PC tissues were reviewed from 60 pts who had undergone biopsy or radical prostatectomy for previously untreated advanced or metastatic PC from 2010 to 2016. 10 samples expressed histologically chromogranin A (CgA), a marker of NED expression. Median age was 67 years (47-80), Gleason score ≥ 7, median PSA was 60 ng/ml (1.3-1000), ECOG 0/1 and bone-visceral sites measurable in 90% of cases. For comparison purposes, 8 pathology specimens from pts with primary PC negative for CgA expression were used. Results: SSTR1-2-4-5 were detected only in the nucleus of PC cells in 10/10 samples. AR was expressed in all 10 samples CgA positive. SSTR3 and AURKA were not expressed in all 10 samples. IL-6 was detected in 9/10 samples. All 10 pts developed early onset of CRPC, more aggressive clinical course with rapid occurrence of visceral metastases and OS was < 12 mos. Conclusions: In metastatic prostate cancer, pretreatment NED pattern can be a predictor for progression and survival after hormonal and during standard chemotherapy. Most likely NEPC become AR negative during disease progression and in response to androgen deprivation therapy. We supposed, according to other data, that the novel potent AR-targeted drugs should be not used in this subset of patients. SSTRs and somatostatin analogs are not potential targets for prostate cancer.