Tubular carcinoma of the breast: Clinico-pathologic features and survival outcome compared with Ductal Carcinoma In Situ

Purpose: Tubular carcinoma (TC) of the breast is an uncommonhistological subtype of invasive breast cancer with an excellentprognosis compared with standard invasive ductal carcinoma. Recent studies suggested a possible precursor role for low gradeductal carcinoma in situ (DCIS) in the development of TC. Thegoal of this analysis was to understand the clinicopathologic featuresand outcomes of TC by comparing TC with DCIS. Methods:A retrospective review identified 70 patients with TC and1,106 patients with DCIS between 1995 and 2011. Student t-testand Fisher exact test were used to compare the clinicopathologiccharacteristics of TC patients with those of DCIS patients. TheKaplan-Meier method and Cox regression analysis were used todetermine disease-free survival (DFS) rates. Results: Comparedto DCIS, TC exhibited favorable clinicopathologic characteristicssuch as a lower nuclear grade (92.3%), higher expression of hormonalreceptors (estrogen receptor-positive, 92.9%; progesteronereceptor-positive, 87.0%), and less frequent overexpressionof human epidermal growth receptor 2 (12.9%). DFS did not differsignificantly between the TC and DCIS groups (5-year DFS,100% vs. 96.7%; 10-year DFS, 92.3% vs. 93.3%; p=0.324),and cancer-specific deaths were not noted in either group. However,axillary lymph node involvement was observed in six (8.6%)of the 70 patients with TC. Three of these patients had small tumors(≤1 cm). Conclusion: In our study cohort, TC was associatedwith an excellent prognosis and a low rate of lymph nodemetastasis. However, lymph nodes metastases were found evenin patients with small tumors (≤1 cm). Axillary staging must beconsidered for all patients with TC of the breast. KCI Citation Count: 17