Metaplastic Carcinoma of the Breast

Abstract

Objective: Metaplastic carcinoma of the breast is a rare malignancy consisting of epithelial and mesenchymal elements. There is no consensus of treatment for primary or regional disease. This study examines the clinical outcomes of patients with metaplastic breast cancer. Methods: A retrospective review of 27 with metaplastic breast cancer between November 1989 and May 2001 identified from a medical center pathology database. Results: A total of 27 patients (1 man and 26 women) had a median age of 52 years (range 30–75). Twenty-five of 27 patients (93%) had palpable tumors. Pathologic sub-types included invasive carcinoma (IC) with pseudosarcomatous metaplasia (13), IC with prominent squamous metaplasia (8), squamous cell carcinoma of ductal origin (3), and spindle cell carcinoma (3). Median tumor size (3.5 cm, range 1.4–9 cm) and estrogen receptor presence (19%) was significantly different than non-metaplastic breast cancers encountered during the same period (n4252, 1.9 cm and 78%, respectively, p Twenty-three patients had primary metaplastic breast cancer (PMBC). Surgical interventions in the PMBC group included 10 segmental mastectomies (BCS) and 13 mastectomies (MTX). Primary tumor size (3.3 cm vs. 3.5 cm) and patient age (51 years vs. 51 years) were similar for the breast conservation (BCS) and mastectomy (MTX) groups. No recurrences or deaths occurred in the BCS patients with a median follow-up of 31 months (range 2–48 months). Two patients had local recurrences after MTX at 13 and 22 months with a median follow-up of 64 months (range 13–141 months). Four patients had recurrent disease. These patients diagnosed with metaplastic recurrence underwent salvage mastectomy (1), BCS (1), axillary resection (1), and chest wall resection (1). Four of 20 patients (20%) with PMBC had axillary metastases including one of 8 (13%) patients undergoing sentinel lymph node biopsy. Axillary metastases were observed in two patients with the pseudosarcomatous metaplasia subtype and two patients with the prominent squamous metaplasia variant. There were no axillary recurrences in the BCS group. Adjuvant chemotherapy was administered to 25 of 27 patients (93%). Conclusions: Metaplastic breast carcinomas were significantly more likely to be larger and hormone receptor negative than non-metaplastic breast carcinomas. Our study suggests that BCS with sentinel lymph node biopsy may be as effective as MTX in the loco-regional treatment of metaplastic breast cancer.