e11617 Background: Neoadjuvant chemotherapy (NAC) for patients with invasive ductal carcinoma (IDC) of the breast is performed as a standard therapy in many hospitals for improving outcomes of IDC patients. The purpose of this study is to identify important prognostic clinicopathological factors for 115 IDC patients who operated in our hospital (1997 to 2002) followed by NAC. Methods: The multivariate analyses with an assessment of pathological effect of NAC, grading system for lymph vessel tumor emboli (LVTE), and histological factors of tumors in lymph nodes in addition to well-known prognostic clinicopathological factors were performed in IDC patients with nodal metastasis and in those of pTNM stage III as well as IDC patients as a whole. Results: Multivariate analyses demonstrated that grading system for LVTE was a significant prognostic factor for IDC patients in the both group. Severe tumor stroma in nodal metastatic tumors significantly increased the HRs of tumor recurrence of IDC patients in the both group. Number of mitotic figures in nodal metastatic tumors significantly increased the HRs of tumor death in IDC patients with nodal metastasis. Tumor necrosis in primary-invasive-tumors was a significant factor for tumor recurrence of patients in the both. Conclusions: The study clearly demonstrated that grading system for LVTE, and characteristics of nodal metastatic tumors as well as the presence of tumor necrosis in primary-invasive tumors are very important prognostic factors for IDC patients who received NAC. Since we already reported a prognostic significance of the factors in IDC patients who did not receive NAC in previous studies, we concluded that the factors are also very important for IDC patients who received NAC to accurately assess their outcome. No significant financial relationships to disclose.
