A proposal for a new classification of T4 breast cancer as stage IIIC: a report from the Korean Breast Cancer Society

Abstract

The objective of this study is to investigate staging system of the stage IIIB and stage IIIC Breast cancer and determine the criteria for an update of the classification system. Since AJCC 6th edition, it is pointed out that stage IIIB showed a worse outcome compared with stage IIIC. Using information from two databases, including the nationwide Korean Breast Cancer Registry (KBCR), three cohorts composed of patients from the Asan Medical Center from 1989 to 2002 (cohort I), from 2003 to 2008 (cohort II), and KBCR from 2003 to 2005 (cohort III) were assembled. New classifications were suggested that rearranged stage IIIB as T1-3N3 disease and stage IIIC as T4 any N disease. From the joint analysis of 9640, invasive breast cancer patients from cohorts I and II showed the stage IIIB group showed a significantly worse DFS (HR 10.4, 95% CI 6.9-15.7) compared with the stage IIIC group (HR 7.2, 95% CI 5.9-8.7). T4d breast cancer showed worse DFS than T4 abc breast cancer but not significant (p = 0.505). The survival of patients with T1N3 and T2N3 tumors was higher than the other groups, and patients with T4N3 tumors showed the worst survival outcomes in terms of DFS, CSS. Using new suggested classification, in cohort III, the stage IIIB HR for CSS was changed from 15.4 (95% CI 10.6-22.1) in the AJCC 6th edition to 12.6 (95% CI 10.1-15.6) in the proposed new staging system. The stage IIIC HR for CSS was changed from 13.3 (95% CI 10.7-16.4) in the AJCC 6th edition to 18.9 (95% CI 14.0-25.6) in the proposed new staging using stage I as a reference. Reclassification of T4 any N disease as stage IIIC and T1-3N3 disease as stage IIIB is appropriate.

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

“…In the present study, we found that the prognostic difference between stage IIIB and stage IIIC was not differentiated properly according to the anatomic TNM staging. The staging limitation was also described by other studies . Further prognostic evaluation indicated that the survival outcome of T1N3/T2N3 in the stage IIIC was significantly better than T3N3 and T4N3 in the same stage, but not different from that of T4N0 in the stage IIIB.…”

“…The staging limitation was also described by other studies. [24][25][26] Further prognostic evaluation indicated that the survival outcome of T1N3/ T2N3 in the stage IIIC was significantly better than T3N3 and T4N3 in the same stage, but not different from that of T4N0 in the stage IIIB. T4N2 group in the stage IIIB showed a similar prognosis compared with T4N3 in the stage IIIC, but had a worse prognosis than other subgroups in the same stage.…”

“…Similarly, Zhu et al reported that the prognosis of T1N3 was significantly better than other groups in the stage IIIC, but was similar to that of T4N1 and T4N2 group in the stage IIIB . Kim and his colleagues proposed a revised TNM staging, in which T1N3/T2N3/T3N3 were incorporated into the stage IIIB, and T4Nany were incorporated into the stage IIIC . The authors believed that T4 was a more important factor influencing the prognosis of BC patients than N3, because there were no survival differences among T4 stage patients when they were stratified according to the nodal status .…”

“…Kim and his colleagues proposed a revised TNM staging, in which T1N3/T2N3/T3N3 were incorporated into the stage IIIB, and T4Nany were incorporated into the stage IIIC . The authors believed that T4 was a more important factor influencing the prognosis of BC patients than N3, because there were no survival differences among T4 stage patients when they were stratified according to the nodal status . More T4 stage patients underwent neo‐adjuvant treatment before curative operation, which may result in the decreased number of positive lymph nodes or N‐stage migration.…”

A retrospective prognostic evaluation analysis using the 8th edition of the American Joint Committee on Cancer staging system for breast cancer

“…Kim et al reported that the survival rate of the IIIB group was lower than that of the IIIC group. A joint analysis of 9640 patients with invasive breast cancer showed that those with stage IIIB disease demonstrated a significantly worse DFS [hazard ratio, HR 10.4; 95% confidence interval (CI) 6.9–15.7] that those with stage IIIC disease (HR 7.2; 95% CI 5.9–8.7) [ 16 ]. Woodward et al yielded similar results, showing a 15-year OS of 18% in stage IIIB disease patients and 28% in stage IIIC disease patients [ 17 ].…”