Indication for adjuvant radiation therapy was associated with higher prostate volume (> 45 cm<sup>3</sup> and 25-45 cm<sup>3</sup>) and advanced tumor characteristics, namely higher prostate-specific antigen value (>20 ng/ml and 10-20 ng/ml), advanced clinical tumor stage (cT3/4 and cT2), lower number of sampled biopsy cores (≤ 12), higher proportion of positive cores (continuous), and higher Gleason Grade Group in biopsy (5, 4, and 3). This evidence concerns the gene KLK3 and neoplasm.