Evaluation of clinical staging of the American Joint Committee on Cancer (eighth edition) for prostate cancer.

OBJECTIVES: This study aimed to evaluate the eighth edition of the American Joint Committee on Cancer (AJCC) for clinical staging of prostate cancer based upon Surveillance, Epidemiology and, End Results (SEER) database.

MATERIALS AND METHODS: Patients diagnosed as prostate adenocarcinoma during 2004-2009 without any surgical treatment to the primary site were selected from the SEER registry. Excluded were cases with incomplete or unavailable staging, PSA and Gleason score information.

RESULTS: A total of 144,443 cases were identified. The median follow-up time was 84 months. The median age at diagnosis was 69 years, and median PSA was 7 ng/ml. CSS at 10th years was 96.2% for cT2a and 86.2% for cT2b/2c, respectively. The survival differences between clinical stage cT2a and cT2b/2c still had statistical significance (P < 0.001). For patients with grade group 1, there was no statistically significant difference for CCS between the cT2a and cT1 (P = 0.310), and between the subgroup of cT1/cT2a with 10 ng/ml ≤ PSA < 20 ng/ml and the subgroup of cT2b/2c with PSA < 20 ng/ml (P = 0.126), respectively. The CSS of IIIA (T1/2 with PSA ≥ 20 ng/ml) was less than IIC (P < 0.001), which has worst prognosis within stage I/II. The prognosis of T1/2 stage with Gleason score grade group 5 and PSA < 20 ng/ml was not only worse than AJCC IIC (P < 0.001) but also worse than AJCC IIIB (P < 0.001).

CONCLUSION: It is necessary to maintain a three-tier system to subdivide T2 disease clinically. For patients with grade group 1, cT2a and cT1 could merge into one group. Organ-confined disease with PSA ≥ 20 ng/ml or grade group 5 should be separated from stage II.