[Effect of the primary tumor location on the prognosis of breast invasive ductal carcinoma patients treated with radical mastectomy].

Objective: To analyze the clinicopathological features and prognosis of breast invasive ductal carcinoma patients receiving radical mastectomy according to the primary tumor location.
Methods: From January 2008 to December 2008, 993 patients with breast invasive ductal carcinoma received radical mastectomy in Tianjin Medical University Cancer Institute and Hospital. Patients were grouped according to the primary tumor location when breast cancer was diagnosed. The clinicopathological characteristics and follow-up information of them was collected and analyzed retrospectively.
Results: Of the 993 patients, primary tumor located in the upper-outer quadrant (UOQ) in 556 patients (56.0%), the lower-outer quadrant (LOQ) in 97 (9.8%), the central portion in 99 (10.0%), the upper-inner quadrant (UIQ) in 186 (18.7%), and the lower-inner quadrant (LIQ) in 55 (5.5%). Patients in the central portion tended to have larger tumors, and more patients in the upper-inner quadrant received endocrine therapy. The estimated 5-year disease-free survival (DFS) rates of patients with primary lesion in the UOQ, LOQ, central portion, UIQ and LIQ were 90.3%, 88.7%, 79.8%, 86.0% and 72.7%, respectively, with significant differences (P<0.001). The 5-year overall survival (OS) rates were 97.5%, 96.9%, 90.9%, 94.1% and 87.3%, respectively, with significant differences (P<0.001). Multivariate analysis showed that 5-year recurrence and metastasis risks were significantly increased in patients with primary lesion in the central portion, UIQ and LIQ compared to other groups (P<0.001), and 5-year mortality risks were increased in these three groups (P=0.002).
Conclusion: Primary lesion located in central portion and inner quadrant is an independent adverse prognostic factor for patients with breast invasive ductal carcinoma patients receiving radical mastectomy.