Evaluation of Prostate Cancer Stage Groups Updated in the 8th Edition of the American Joint Committee on Cancer Tumor–Node–Metastasis Staging Manual

Introduction

The American Joint Committee on Cancer (AJCC) tumor, node, metastasis classification system (TNM) staging manual has been updated and provides more specified stage grouping for prostate cancer (PCa). We aimed to validate the updated AJCC stage groups for PCa using a radical prostatectomy (RP) cohort.

Patients and Methods

We analyzed the data of 3032 patients previously treated with RP for localized PCa. We stratified patients into stage groups according to the 8th edition of the AJCC manual and compared biochemical recurrence (BCR)-free survival using Kaplan-Meier analyses.

Results

There were 217 patients in stage group I, 33 in IIA, 1101 in IIB, 535 in IIC, 129 in IIIA, 781 in IIIB, and 236 in IIIC. There were no significant differences in BCR-free survival between stage groups IIC and IIIA (P = .875). Subsequently, the low–Gleason score (GS) IIIA subgroup (GS ≤ 3 + 4, P = .025) showed superior BCR-free survival than the IIC group, and the high-GS IIIA subgroups (GS ≥ 4 + 3, P = .004) showed a poorer BCR-free survival than the IIC group. Furthermore, there were no significant differences between groups I and IIA (P = 330) and between groups IIA and IIB (P = .942). Our new staging system provided a better ability to discriminate the prognosis of each group. However, our study has several limitations, such as retrospective design, relatively short follow-up period, and need for further validation.

Conclusion

The current AJCC prognostic groups show some contradictory results, particularly concerning prognosis of the IIC and IIIA groups. We suggest that GS be given more weight than serum prostate-specific antigen level in stage group stratification.