Correlation of Preoperative Ki67 and Serum CA15.3 Levels with Outcome in Early Breast Cancers a Multi Institutional Study.

BACKGROUND: To investigate the association between preoperative pathological Ki67 labeling index and serum tumor marker cancer antigen 153 (CA 153) with clinicpathological parameters and treatment outcomes in early breast cancer.

MATERIALS AND METHODS: A retrospective study at 4 cancer centers in Saudi Arabia and Egypt was performed. Data were collected for female patients diagnosed with unilateral early breast cancer between March 2010 and October 2013. Cases treated with neoadjuvant chemotherapy (NACT) followed by surgery and radiotherapy were included. NACT included 68 cycles of anthracycline and taxane based regimens. Trastuzumab and hormonal treatments were added according to HER2 and hormone receptor status. Baseline serum CA15.3 and pathological Ki67 levels were evaluated and correlated with disease free survival (DFS) and overall survival (OS).

RESULTS: A total of 280 pts was included. The median age was 49 years (3866 y) and median overall survival was 35 (2038) months (mo). Estrogen receptors (ER), progesterone receptors (PR) and HER 2 receptors were positive in 233 (83.2%), 198 (70%) and 65 cases (23.2%), respectively. High preoperative Ki67 and CA15.3 were noted in 177 (63.2%) and 131 (46.8%). A total of 45 (16%) patients had distal or local recurrence and 24 (8.6%) died of their disease. Most of the relapsed cases had high preoperative Ki67 (n=41, 91%) and CA15.3 (n=28, 62%) values. All of the patients who died had a high Ki67 but CA15.3 was high in 9 (37%) only. Mean DFS/OS in patients with high preoperative Ki67 was 32 months /32 months as compared to 37 months/35 months in those with normal Ki67 (p<0.001). Correlation of preoperative CA15.3 and survival was statistically not significant.

CONCLUSIONS: Preoperative Ki67 can be a predictive and prognostic marker. Higher levels are associated with poor DFS and OS in patients with early BC.