Concurrent AURKA and MYCN Gene Amplifications Are Harbingers of Lethal TreatmentRelated Neuroendocrine Prostate Cancer

Abstract

Neuroendocrine prostate cancer (NEPC), also referred to as anaplastic prostate cancer, is a lethal tumor that most commonly arises in late stages of prostate adenocarcinoma (PCA) with predilection to metastasize to visceral organs. In the current study, we explore for evidence that Aurora kinase A (AURKA) and N-myc (MYCN) gene abnormalities are harbingers of treatment-related NEPC (t-NEPC). We studied primary prostate tissue from 15 hormone naïve PCAs, 51 castration-resistant prostate cancers, and 15 metastatic tumors from 72 patients at different stages of disease progression to t-NEPC, some with multiple specimens. Histologic evaluation, immunohistochemistry, and fluorescence in situ hybridization were performed and correlated with clinical variables. AURKA amplification was identified in overall 65% of PCAs (hormone naïve and treated) from patients that developed t-NEPC and in 86% of metastases. Concurrent amplification of MYCN was present in 70% of primary PCAs, 69% of treated PCAs, and 83% of metastases. In contrast, in an unselected PCA cohort, AURKA and MYCN amplifications were identified in only 5% of 169 cases. When metastatic t-NEPC was compared to primary PCA from the same patients, there was 100% concordance of ERG rearrangement, 100% concordance of AURKA amplification, and 60% concordance of MYCN amplification. In tumors with mixed features, there was also 100% concordance of ERG rearrangement and 94% concordance of AURKA and MYCN co-amplification between areas of NEPC and adenocarcinoma. AURKA and MYCN amplifications may be prognostic and predictive biomarkers, as they are harbingers of tumors at risk of progressing to t-NEPC after hormonal therapy.