Primary tumor location impacts breast cancer survival

Background: The prognostic significance of tumor location in breast cancer remains unclear. To better understand this relationship, we evaluated the Department of Defense tumor registry. Methods: Patients with infiltrating ductal adenocarcinoma or lobular carcinoma over a 10-year period were identified and analyzed. Results: Of the 13,984 tumors, 7,871 (58%) originated from the upper-outer quadrant or axillary tail, whereas the remainder were found at the nipple complex (9%), upper-inner quadrant (14%), lower-inner quadrant (9%), and lower-outer quadrant (10%). Univariate analysis of cancer-specific survival revealed a significant difference based on location of the primary breast cancer. Upper-outer quadrant lesions were associated with an independent contribution toward a survival benefit. Conclusions: Upper-outer quadrant breast cancers have a more favorable survival advantage when compared with tumors in other locations. Factors that negatively impacted survival included high-grade tumors, advanced stage, and race.