Primary tumor location impacts breast cancer survival

The prognostic significance of tumor location in breast cancer remains unclear. To better understand this relationship, we evaluated the Department of Defense tumor registry.

Patients with infiltrating ductal adenocarcinoma or lobular carcinoma over a 10-year period were identified and analyzed.

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.

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.