Prognostic significance of Ki67 in Chinese women diagnosed with ER+/HER2− breast cancers by the 2015 St. Gallen consensus classification

Prognostic significance of Ki67 in Chinese women diagnosed with ER+/HER2− breast cancers by the 2015 St. Gallen consensus classification

BMC Cancer, January 2017

28061893

Yue Hu, Ran Gu, Jinghua Zhao, Yaping Yang, Fengtao Liu, Liang Jin, Kai Chen, Haixia Jia, Hongli Wang, Qiang Liu, Fengxi Su, Weijuan Jia

This study evaluated the distribution pattern of the Ki67-labeling index (LI) among patients at a Chinese breast cancer center, and analyzed its prognostic significance in the 2015 St Gallen consensus breast cancer classification, estrogen receptor-positive and human epidermal growth factor receptor 2-negative(ER(+)/HER2(-))subtype. We classified 939 women with ER(+)/HER2(-) breast cancer into three groups by Ki67-LI levels, and followed their clinicopathologic characteristics and prognoses. In the 939 eligible subjects, 342 had Ki67-LI ≤10% (Ki67(Low)), 281 had Ki67-LI between 10 and 30% (Ki67(Medium)), and 316 had Ki67-LI ≥30% (Ki67(High)). Although the Ki67(High) group had less favorable clinicopathologic factors, the Ki67(Medium) group's factors varied considerably. Kaplan-Meier estimates showed that disease-free survival(DFS) for the Ki67(Medium) group was significantly shorter than the Ki67(Low) group but longer than the Ki67(High) group. Ki67-LI had independent prognostic significance in multivariate analysis. Other diagnostic factors, including tumor size >2 cm, positive lymph nodes, and grade III disease, were significantly associated with poorer disease-free survival only in the Ki67(Medium) group. For patients with ER(+)/HER2(-) breast cancer, we confirmed three distinct risk patterns by Ki67-LI levels according to the 2015 St Gallen consensus. For patients with clearly low or high Ki67-LI, straightforward clinical decisions could be offered, but for patients with intermediate Ki67-LI, other factors might provide valuable information.