Validation of the Prognostic Significance of the Prognostic Stage Group According to the Eighth Edition of American Cancer Joint Committee on Cancer Staging System in Triple-Negative Breast Cancer: An Analysis From Surveillance, Epidemiology, and End Results 18 Database.

Background: The eighth edition of the American Cancer Joint Committee on Cancer (AJCC) staging system for breast cancer put forward the prognostic stage groups for the first time based on the traditional anatomic tumor-node-metastasis staging system. Our study intends to validate the predictive significance of the eighth edition staging system in triple-negative breast cancer (TNBC) patients.

Materials And Methods: We collected and accessed 26,589 eligible cases of TNBC from the Surveillance, Epidemiology, and End Results database (2010-2015) and reclassified the patient cohort according to the eighth edition of the AJCC staging system into anatomic and prognostic stages.

Results: The results showed that more than half of the patients upstaged in the prognostic stage when compared with the anatomic stage. By comparing with the anatomic stage, the prognostic stage had a higher likelihood ratio and linear trend χ values. The prognostic stage group also had higher Akaike information criterion and Bayesian information criterion values than the anatomic stage group.

Conclusions: The prognostic staging system in TNBC patients performs more optimistic prognostic stratification and predictability than the anatomic staging system. Moreover, the latest AJCC staging system has a milestone importance to the history of breast cancer staging system.