The assessment of 8th edition AJCC prognostic staging system and a simplified staging system for breast cancer: The analytic results from the SEER database

The prognostic value of the prognostic staging system that incorporated estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor-2 (Her-2), and histological grade has been validated in breast cancer (BC) patients, but the staging system seems to be somewhat complex. Recently, an updated bioscore system based on these tumor biological factors was proposed. The purpose of this study was to compare the prognostic stratification between prognostic staging system of American Joint Commission on Cancer (AJCC) and a simplified staging system based on the bioscore system and anatomic TNM staging for BC patients. A total of 44 593 patients with invasive ductal carcinoma who underwent radical resection between 2010 and 2011 were reviewed using the SEER database. The patients were reclassified into different groups according to the anatomic staging system, prognostic staging system, risk bioscore system, and simplified staging system, respectively. The prognostic differences between different groups were compared and clinicopathologic features were analyzed. The anatomic TNM staging failed to clearly distinguish the prognostic difference between stage IIIB and stage IIIC. Therefore, we proposed an adjusted anatomic staging, in which T1N3 and T2N3 were downstaged from stage IIIC to stage IIIB, and T4N2 was upstaged from stage IIIB to stage IIIC. Histological grade III, ER(−), PR(−), and Her-2(−) were identified as independent prognostic factors in the multivariate analysis, and these factors were separately marked as 1 point. There were significant survival differences among different risk points except for the comparison between 0 and 1 point. The higher the risk points, the poorer the prognosis of BC patients. In addition, the curve distance between stage IIA and stage IIB was not significantly broaden according to the prognostic staging system. However, the prognostic stratification for BC patients could be significantly improved by the simplified staging system incorporated the bioscore system and adjusted anatomic staging. Several drawbacks may still exist in the prognostic staging system of AJCC. A simplified staging system that incorporated risk score system and the anatomic staging could provide more accurate prognostic information for BC patients.