Aim: To study an importance of new 2016 WHO histologic grading system for prostate cancer in evaluating the risk of progressing after conformal external beam radiation therapy, brachytherapy 125I and androgen deprivation therapy.
Materials and methods. A total of 53 patients with prostate acinar adenocarcinoma were undergone to conformal external beam radiation therapy, brachytherapy 125I and androgen deprivation therapy. Age of patients was 54-80 years (68.11±4.7 years). T3 and T2 prostate cancer was diagnosed in 42 (79.3%) and 11 (20,7%) patients, respectively. Baseline PSA level ranged from 5.5 ng/ml to 311 ng/ml (39.7±7.9 ng/ml). According to the new grading system (the WHO classification, 2016), all patients were divided into five risk groups.
Results. Median follow-up was 64.9 months. The biochemical progression was seen in two patients, while three patients had metastatic disease. All patients with progressing prostate cancer were from IV and V prognostic groups. The 5-year progression-free survival rates for patients of IV–V and I–III groups were 44, 4% and 100%, respectively.
Conclusions. According to the results of combination treatment (conformal external beam radiotherapy, brachytherapy 125I and hormonal therapy), progression-free survival rate in patients of IV (Gleason 4+4=8) and V (Gleason 4+5=9 or 5+5=10) groups, according to new WHO grading system were significantly lower, in comparison with patients of I (Gleason 3+3=6), II (Gleason 3+4=7) and III groups (Gleason 4+3=7). Our study showed that new WHO classification allows to predict the progression of prostate cancer not only after prostatectomy, but also after conformal external beam radiation therapy, combined with brachytherapy 125I and androgen deprivation therapy.

Keywords: prognostic groups, Gleason score, prostate acinar adenocarcinoma, radiation therapy, prostate cancer