[231] Metaplastic Sarcomatoid Carcinoma of the Breast: Poor Overall Survival Is Independent of the Amount of Sarcomatoid Component

TR Lester, KM Nayeemuddin, WG Davis, KK Hunt, MZ Gilcrease. The University of Texas M.D. Anderson Cancer Center, Houston, TX

Background: Metaplastic carcinomas of the breast with a pure or predominant sarcomatoid morphology are known to have a poor clinical outcome, but it is unclear whether metaplastic carcinomas with smaller sarcomatoid components are equally aggressive.
Design: We examined the clinicopathologic features of forty-eight cases of metaplastic sarcomatoid carcinoma with the sarcomatoid component comprising from 5% to 100% of the tumor. Those with pure sarcomatoid morphology were included if they had immunohistochemical expression of cytokeratin and/or associated ductal carcinoma in situ and if the patients did not receive neoadjuvant chemotherapy. Patients with low-grade fibromatosis-like metaplastic tumors and other metaplastic tumors with a low-grade spindle cell component were excluded.
Results: Axillary lymph node dissection or limited axillary node excision was performed in 31 patients. Lymph node involvement occurred in 10 patients. Seven of these had a carcinomatous component comprising 75% to 90% of the primary tumor. Two patients with a carcinomatous component comprising 15% and <5% of the primary tumor had only micrometastases, and one patient without an overt carcinomatous component had only isolated tumor cells in a lymph node. Clinical follow-up was available for 38 patients and ranged from 2 to 201 mos (median 25 mos). Ten patients (26%) had locoregional recurrence, sixteen patients (42%) developed distant metastases, and eight (21%) had both. Locoregional recurrence-free survival, distant metastasis-free survival and overall survival were not dependent on the amount of sarcomatoid component in the primary tumor. Five-year overall survival for patients with 95% and <95% sarcomatoid component in the primary tumor was 46% 11% and 44% 14%, respectively (P=0.50). Five-year overall survival for patients with >10% and 10% sarcomatoid component in the primary tumor was 45% 9% and 40% 22%, respectively (P=0.50).
Conclusions: Metaplastic carcinomas of the breast with an intermediate to high-grade sarcomatoid component are aggressive tumors. Lymph node metastases tend to occur in patients without a predominant sarcomatoid component, but the amount of sarcomatoid component is not significantly associated with disease recurrence or overall survival.
Category: Breast

Monday, March 9, 2009 9:30 AM

Poster Session I Stowell-Orbison/Autopsy Award # 37, Monday Morning