Stathmin and phospho-stathmin protein signature is associated with survival outcomes of breast cancer patients

// Xia-Ying Kuang 1, 2, * , Li Chen 1, 2, * , Zhi-Jie Zhang 4 , Yi-Rong Liu 1, 2 , Yi-Zi Zheng 1, 2 , Hong Ling 2 , Feng Qiao 2 , Shan Li 2 , Xin Hu 2 , Zhi-Ming Shao 1, 2, 3 1 Key Laboratory of Breast Cancer in Shanghai, Department of Breast Surgery, Fudan University Shanghai Cancer Center, Shanghai, China 2 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China 3 Institutes of Biomedical Science, Fudan University, Shanghai, China 4 Department of Epidemiology and Biostatistics, School of Public Health, Fudan University, Shanghai, China * These authors have contributed equally to this work Correspondence to: Zhi-Ming Shao, e-mail: zhimingshao@yahoo.com Xin Hu, e-mail: xinhu@fudan.edu.cn Keywords: stathmin, phosphorylation, breast cancer, prognostic model, paclitaxel Received: March 11, 2015 Accepted: June 01, 2015 Published: June 13, 2015 ABSTRACT Currently, Stathmin1 (STMN1) and phospho-STMN1 levels in breast cancers and their clinical implications are unknown. We examined the expression of STMN1 and its serine phospho-site (Ser16, Ser25, Ser38, and Ser63) status by immunohistochemistry. Using Cox regression analysis, a STMN1 expression signature and phosphorylation profile plus clinicopathological characteristics (STMN1-E/P/C) was developed in the training set ( n = 204) and applied to the validation set ( n = 106). This tool enabled us to separate breast cancer patients into high- and low-risk groups with significantly different disease-free survival (DFS) rates ( P < 0.001). Importantly, this STMN1-E/P/C model had a greater prognostic value than the traditional TNM classifier, especially in luminal subtype breast cancer ( P = 0.002). Further analysis showed that patients in the low-risk group would benefit more from adjuvant paclitaxel-based chemotherapy ( P = 0.002). In conclusion, the STMN1-E/P/C signature is a reliable prognostic indicator for luminal subtype breast cancer and may predict the therapeutic response to paclitaxel-based treatments, potentially facilitating individualized management.