Evaluation of the major changes in eighth edition of the American Joint Committee on Cancer pathological staging for prostate cancer treated with prostatectomy

This study aimed to evaluate the major changes of the eighth edition of the American Joint Committee on Cancer (AJCC) pathologic staging for prostate cancer treated with radical prostatectomy. A total of 138,176 patients diagnosed with prostate adenocarcinoma undergoing radical prostatectomy were selected from the Surveillance, Epidemiology and End Results (SEER) database during 2004-2014 period. Excluded were cases with incomplete or unavailable staging, PSA and Gleason score information. Two subgroups were established: group a, T2 stage with PSA >= 20ng/ml; group b, T2 stage with Gleason score grade group 5 and PSA<20ng/ml. The median follow-up time was 58 months. The median age at diagnosis for the overall group was 61 years, and the median PSA was 5.7ng/ml. Cancer-specific survival (CSS) at tenth years was 99.3% for T2a/T2b, 99.2% for T2c, respectively. The survival differences between T2a/T2b and T2c did not have statistical significance (P = .323). It was necessary for the current eighth edition to define a single pathologic T2 category, eliminating the subcategories, for all organ-confined disease. CSS at the tenth years was 98.4% for group a, 92.6% for group b, respectively. The prognosis of group a was worse than AJCC II (P = .002). The prognosis of group b was not only worse than AJCC II (P < .001), but also worse than AJCC IIIB. There was necessity to separate the disease with PSA >= 20ng/ml or Gleason score grade group 5 from other organ-confined disease. The present study supported the scientificity of the eighth edition of AJCC pathologic staging for prostate cancer.