[336] Prognostic Factors of Primary Invasive Mammary Neuroendocrine Carcinoma: Clinicopathologic Analysis of 74 Cases

B Wei, Z Tian, F Tang, W Wei, MZ Gilcrease, L Huo, CT Albarracin, E Resetkova, LP Middleton, A Sahin, J Chen, SC Abraham, Y Wu. West China Hospital, Sichuan University, Chengdu, Sichuan, China; Ninth People's Hospital, Shanghai Jiao Tong University, Shanghai, China; Huashan Hospital, Fudan University, Shanghai, China; The University of Texas M.D. Anderson Cancer Center, Houston, TX

Background: Primary Neuroendocrine carcinoma (NEC) of the breast is an uncommon neoplasm. It was identified more than four decades ago, but its diagnostic criteria was not well defined till 2003, when WHO histologic classification of the breast tumors define this tumor having >50% of the tumor cells expressing neuroendocrine markers. The biological behaviour and prognostic factors of this type of tumor is not fully studied.
Design: Seventy-four mammary NEC cases from the Surgical Pathology file at The University of Texas M.D. Anderson Cancer Center were retrieved and reviewed, and the diagnoses were confirmed based on the positive immunohistochemical reaction to neuroendocrine marker synaptophysin and/or chromogranin in >50% of the invasive tumor cells. Clinicopathologic features and outcome data of these cases were obtained.
Results: Univariate analyses showed that large tumor size, high nuclear grade, presence of lymphovascular invasion in the primary tumor, and regional lymph node metastasis were adverse prognostic factors for distant recurrence-free survival; and that large tumor size, high nuclear grade, high Ki-67 proliferation index and regional lymph node metastasis were adverse prognostic factors for overall survival. Multivariate analysis revealed that presence of lymphovascular invasion and regional lymph node metastasis were independent adverse prognostic factors for distant recurrence-free survival; and that Ki-67 proliferation index was an independent prognostic factor for overall survival. Interestingly, this study also found that histologic grading system based on the assessment of tubule/gland formation, nuclear pleomorphism and mitotic counts, is not prognostically significant in predicting distant recurrence-free survival and overall survival by both univariate and multivariate analyses.
Conclusions: This study suggest that NEC is a distinct clinicopathologic entity. Ki-67 proliferation index is a valuable prognostic marker in this type of tumor and should be routinely evaluated.
Category: Breast

Tuesday, March 23, 2010 8:30 AM

Platform Session: Section C, Tuesday Morning

 

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