BACKGROUND We compared pathological prognostic stage (PPS) with anatomic stage (AS) groups according to the updated version of breast cancer staging of the American Joint Committee on Cancer (AJCC) 8th Edition. MATERIAL AND METHODS We evaluated 353 breast cancer patients initially treated with surgery. AS and PPS were performed by evaluating the pathological data of the patients according to the AJCC 8th Edition breast cancer updated version. Stages and survival rates between the 2 staging systems were evaluated and compared. Disease-free survival (DFS) and disease-specific survival (DSS) were calculated according to both staging systems using Kaplan-Meier test. After the PPS change was made in each AS group, 10-year DFS and 10-year DSS of the changed groups were compared using the chi-square test. RESULTS The median follow-up was 114 months and the median age was 48 years. In 192 (54.4%) patients the stage change. The most significant change was 1-level downstaging in 70 (22.4%) patients, and 2-levels downstaging in 78 (22.1%) patients. Five-year DFS, 10-year DFS, 5-year DSS rate, and 10-year DSS were 86.3%, 80.3%, 93.8%, and 84.1%, respectively. The PPS system was found to provide better prognostic information when the patients with AS IIB and IIIA groups were compared according to the PPS. CONCLUSIONS According to the updated version of the AJCC 8th Edition, half of our patients had stage change when they were evaluated according to AS and PPS system. PPS gives better information about prognosis than does AS.