20 Background: Medullary carcinoma (MC) represents a rare breast cancer subtype associated with a rather favorable prognosis compared with invasive ductal carcinoma (IDC). It is characterized by the high-grade structure and lymphocytic infiltration, hemorrhagic necrosis. The purpose of this study is to compare the clinicopathologic characteristics and outcome of MC to IDC. Methods: We retrospectively reviewed the medical records of patients with invasive breast cancer managed with operation at Samsung Medical Center in Korea from January 1995 to June 2010 except patients diagnosed with ductal carcinoma in situ, patients with distant metastasis at diagnosis or neoadjuvant chemotherapy. 52 cases were identified with MC; 5,716 patients with IDC. The clinicopathologic features, disease-free survival (DFS) and overall survival (OS) for patients with MC were compared with those of the IDC patients. Results: The medullary group presented at younger age (43.9 ± 8.8 vs 47.7 ± 9.9, p=0.006). Also the medullary group was significantly associated with higher histological grade (poor; 80.0 vs 38.3%, p=0.003) and nuclear grade (grade3; 82.8 vs 41.7%, p<0.001) as well as negative ER (84.8 vs 31.0%, p<0.001) and PR status (91.3 vs 38.8%, p<0.001) regarded as poor prognostic factors. But lymphatic invasion was rare (0.0 vs 29.8%, p<0.001) and N stage was low (N0; 86.5 vs 58.4%, p<0.001). The DFS and OS were not significantly different between the medullary and IDC groups. (5-yr DFS : 88.0 vs 89.2 %, p=0.917, 5-yr OS : 94.4 vs 93.4%, p=0.502) In multivariable analysis, factors associated with DFS and OS included nuclear grade, histological grade, tumor size, lymph node metastasis, ER/PR/C-erbB2 status, chemotherapy and hormone therapy. When adjusting for other factors, histological type itself did not show significant difference from IDC in DFS and OS. Conclusions: Despite MC present specific clinicopathologic features, prognosis is not different from IDC and determined by already known prognostic factors such as tumor size, lymph node metastasis. Therefore, the patients with MC also need aggressive treatment like IDC.
Thrombospondin-1 is highly expressed in desmoplastic components of invasive ductal carcinoma of the breast and associated with lymph node metastasis
