RESUMEN
<p><b>OBJECTIVE</b>Pure epithelial breast metaplastic carcinoma is a rare and highly malignant tumor. In this study, our purpose was to analyze the clinical features, treatment method and prognostic factors, so to explore the approach for early diagnosis and appropriate treatment of this cancer.</p><p><b>METHODS</b>Clinical data of 22 patients with histopathologically confirmed pure epithelial breast metaplastic carcinoma and treated at Tianjin Cancer Hospital from 1974 to 2008, were reviewed retrospectively. Survival rate was calculated by life tables. Kaplan-Meier unvariate analysis and Log-rank test were used to compare the survival rates. Multivariate factors for survival were analyzed by Cox proportional hazards regression model.</p><p><b>RESULTS</b>The median age of the 22 cases of pure epithelial breast metaplastic carcinoma was 52.5 years. Among them 20 cases went to see a doctor for painless mass, and two cases shown as skin inflammation. Clarifying a diagnosis was difficult before operation so that its diagnosis mainly depended on postoperative histopathologic examination. Twelve cases had axillary lymph node metastasis, 7 cases distant metastasis, and the lung was the most common metastatic organ. The 5-year survival rate was 55.6%, with a median follow-up of 46 months. It was found by Kaplan-Meier unvariate analysis that the age (P = 0.044), number of positive axillary lymph nodes (P = 0.011) and therapeutic schedule (P = 0,003) significantly influenced the outcome of the patients, but tumor size (P = 0.194) was not. Cox multivariate analysis results showed that number of positive axillary lymph nodes was independent prognostic factor for pure epithelial breast metaplastic carcinoma (P = 0.038).</p><p><b>CONCLUSIONS</b>Pure epithelial breast metaplastic carcinoma is seldom seen. It is easy to cause distant metastasis and has a poor prognosis. ER, PR and HER-2 expressions in most samples are negative. The more axillary lymph nodes have metastasis, the poorer is the prognosis. A reasonable and comprehensive treatment can improve the prognosis obviously.</p>