Clinical-pathologic features and long-term outcomes of tubular carcinoma of the breast compared with invasive ductal carcinoma treated with breast conservation therapy.

Abstract

To evaluate our institutional experience of treating tubular carcinoma of the breast (TC) and invasive ductal carcinoma (IDC) with conservative surgery and radiation therapy, to compare clinical-pathologic features and long-term outcomes. A review of our institution's tumor registry from 1975 to 2007, followed by a central pathology review of available slides, yielded 71 cases of Stage I/II TC and 2,238 cases of Stage I/II IDC treated with breast conservation therapy. Clinical-pathologic features and outcomes were analyzed by subtype to detect significant differences. The median follow-up was 7 years. The TC cohort presented more frequently with pT1 disease (97% vs. 80%, p = 0.0007), pN0 disease (95% vs. 74%, p = 0.0004), hormone-receptor positivity (ER+, 89% vs. 62%, p = 0.0001; PR+, 81% vs. 52%, p = 0.0001), and HER-2 negativity (89% vs. 71%, p = 0.04). Clinical outcomes also favored the TC cohort, with lower rates of breast cancer-related death (1% vs. 10%; p = 0.0109) and distant metastasis (1% vs. 13%; p = 0.0028) and higher rates of 10-year overall (90% vs. 80%; p = 0.033), cause-specific (99% vs. 86%; p = 0.011), and disease-free (99% vs. 82%; p = 0.003) survival. There was a nonsignificant trend toward improved breast cancer relapse-free survival for the TC cohort (95% vs. 87%; p = 0.062) but no difference in nodal relapse-free survival or contralateral breast cancer relapse-free survival (all p values >0.05) between the cohorts. Our institutional experience suggests that TC, when compared with IDC, is associated with more favorable clinical-pathologic features and comparable, if not superior, outcomes after breast conservation therapy, suggesting the appropriateness of a conservative approach to this rare subtype.