Expression and Genetic Variation in Neuroendocrine Signaling Pathways in Lethal and Nonlethal Prostate Cancer among Men Diagnosed with Localized Disease.

Background: Recent data suggest that neuroendocrine signaling pathways may play a role in the progression of prostate cancer, particularly for early-stage disease. We aimed to explore whether expression of selected genes in the adrenergic, serotoninergic, glucocorticoid, and dopaminergic pathways differs in prostate tumor tissue from men with lethal disease compared with men with nonlethal disease.
Methods: On the basis of the Swedish Watchful Waiting Cohort, we included 511 men diagnosed with incidental prostate cancer through transurethral resection of the prostate during 1977-1998 with follow-up up to 30 years. For those with tumor tissue (N = 262), we measured mRNA expression of 223 selected genes included in neuroendocrine pathways. Using DNA from normal prostate tissue (N = 396), we genotyped 36 SNPs from 14 receptor genes. Lethal prostate cancer was the primary outcome in analyses with pathway gene expression and genetic variants.
Results: Differential expression of genes in the serotoninergic pathway was associated with risk of lethal prostate cancer (P = 0.007); similar but weaker associations were noted for the adrenergic (P = 0.014) and glucocorticoid (P = 0.020) pathways. Variants of the HTR2A (rs2296972; P = 0.002) and NR3CI (rs33388; P = 0.035) genes (within the serotoninergic and glucocorticoid pathways) were associated with lethal cancer in overdominant models. These genetic variants were correlated with expression of several genes in corresponding pathways (P < 0.05).Conclusions: Our findings lend support to hypothesis that the neuroendocrine pathways, particularly serotoninergic pathway, are associated with lethal outcome in the natural course of localized prostate cancer.Impact: This study provides evidence of the role of neuroendocrine pathways in prostate cancer progression that may have clinical utility. Cancer Epidemiol Biomarkers Prev; 26(12); 1781-7. ©2017 AACR. ©2017 American Association for Cancer Research.