Where is It? Breast Cancer Location and Associations with Metastasis and Survival
Leonard-Murali S, Burmeister C, Susick L, Baker P, and Nathanson S. Where is It? Breast Cancer Location and Associations with Metastasis and Survival. Journal of the American College of Surgeons 2020; 231(4):e88-e89.
Journal of the American College of Surgeons
Introduction: Associations of primary breast cancer (BC) location on development of regional lymph node metastases (RLNM), distant metastases (DM), and mortality remain unclear. We aimed to characterize any associations, hypothesizing that upper-outer quadrant tumors would be associated with RLNM, DM, and reduced survival.
Methods: Hormone-receptor positive, HER2-neu negative BC patients who underwent surgery (including RLN sampling) at a tertiary-care hospital system from 1995-2017 were prospectively reviewed. BC location was described as lower-inner quadrant (LIQ), lower-outer quadrant (LOQ), upper-inner quadrant (UIQ), upper-outer quadrant (UOQ), or central (C). Demographic and clinicopathologic variables were compared between location groups. Kaplan-Meier curves were constructed to analyze mortality by location. Multivariable logistic regression models were constructed to identify associations with RLNM or DM. Significance was established at p<0.05.
Results: 1822 patients met inclusion criteria. Location was most often UOQ, and least often C (C=65, 3.6%; LIQ=217, 11.9%; LOQ=244, 13.4%; UIQ=397, 21.8%; UOQ=899, 49.3%). There was no difference in RLNM between groups (C=15, 23.1%; LIQ=51, 23.5%; LOQ=61, 25.0%; UIQ=65, 16.4%; UOQ=204, 22.7%; p=0.057), and no difference in DM between groups (C=3, 4.6%; LIQ=21, 9.8%; LOQ=14, 5.8%; UIQ=24, 6.1%; UOQ=58, 6.5%; p=0.351). Kaplan-Meier curves showed no difference in survival between groups. By multivariable analysis, UIQ was associated with RLNM (reference group: UOQ; odds ratio=0.67, 95% confidence interval=0.47-0.94; p=0.021), with no other associations between location and RLNM or DM found.
Conclusion: There were no consistent differences in RLNM, DM, or survival between BC locations. Location does not appear to be a prognostic factor in hormone-receptor positive, HER2-neu negative BC.