Genetic variants of the autophagy pathway as prognostic indicators for prostate cancer

Autophagy is a complex process of autodigestion in conditions of cellular stress, and it might play an important role in the pathophysiology during carcinogenesis. We hypothesize that genetic variants of the autophagy pathway may influence clinical outcomes in prostate cancer patients. We genotyped 40 tagging single-nucleotide polymorphisms (SNPs) from 7 core autophagy pathway genes in 458 localized prostate cancer patients. Multivariate Cox regression was performed to evaluate the independent association of each SNP with disease progression. Positive findings were then replicated in an independent cohort of 504 advanced prostate cancer patients. After adjusting for known clinicopathologic factors, the association between ATG16L1 rs78835907 and recurrence in localized disease [hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.54-0.90, P = 0.006] was replicated in more advanced disease (HR 0.78, 95% CI 0.64-0.95, P = 0.014). Additional integrated in silico analysis suggests that rs78835907 tends to affect ATG16L1 expression, which in turn is correlated with tumor aggressiveness and patient prognosis. In conclusion, genetic variants of the autophagy pathway contribute to the variable outcomes in prostate cancer, and discovery of these novel biomarkers might help stratify patients according to their risk of disease progression.