[145] Post Treatment High Ki67 Expression Level (>10%) Is Significantly Associated with Distant Metastasis in Triple-Negative Breast Carcinomas Treated with Neoadjuvant Chemotherapy Followed by Surgery.

Lei Duan, Jingsheng Yan, Venetia Sarode, Roshni Rao, A Marilyn Leitch, David Euhus, Dengfeng Cao, Xian-Jin Xie, Yan Peng. University of Texas Southwestern Medical Center, Dallas; Washington University School of Medicine, St. Louis, MO

Background: Triple-negative (TN) breast carcinoma characterized by negativity for estrogen receptor, progesterone receptor, and Her2, is a group of aggressive tumors. TN tumors usually have high Ki67 expression that is associated with poor prognosis. Neoadjuvant chemotherapy followed by surgery has become the standard of care for locally advanced breast cancer. Previous studies have demonstrated that chemotherapy can alter Ki67 expression level. The aims of this study were to investigate the association between post treatment Ki67 expression and disease progression in patients with TN breast carcinoma in the setting of post neoadjuvant chemotherapy.
Design: Clinical characteristics and tumor profiles were analyzed in 33 TN tumors that were high-grade invasive carcinomas. All of the patients developed distant metastasis after the treatment of neoadjuvant chemotherapy followed by surgery. Ki67 immunostain was performed on the resected tumors. The tumors were divided into 2 groups based on the Ki67 expression (high Ki67 >10% vs. low Ki67 ≤10%). The associations between Ki67 expression and distant metastasis were compared between the 2 groups.
Results: The Ki67 expression level (>10%) was significantly associated with distant metastasis in the TN tumors (p<0.05; Fisher's exact test.

To determine if the Ki67 expression was an independent predictor for distant metastasis in the patients, univariate and multivariate analyses were performed. Although the multivariate analysis did not show statistical significance, the uivariate analysis revealed that the high Ki67 expression was borderline significantly associated with distant metastasis (p=0.056).
Conclusions: Our results indicate that post treatment high Ki67 expression (>10%) is significantly associated with distant metastasis in TN tumors, suggesting that Ki67 may have potential predictive value for disease progression in TN breast cancer patients after the treatment of neoadjuvant chemotherapy followed by surgery. A larger case series to study post treatment Ki67 is needed to better delineate its role as potential prognostic marker.
Category: Breast

Monday, February 28, 2011 1:00 PM

Poster Session II # 67, Monday Afternoon


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