Objective: Several research have suggested that high body mass index (BMI) and diabetes were related to poor breast cancer prognosis. The purpose of this study was to investigate the relationships between BMI/diabetes and the prognosis of bilateral breast cancer (BBC).
Methods: A total of 26 992 patients with primary breast cancer underwent operations at the Tianjin Medical University Cancer Institute and Hospital between January 1971 and November 2011. Among them, 512 consecutive patients with BBC and 1024 patients with unilateral breast cancer (UBC) were retrospectively reviewed. Overall survival (OS) and progression-free survival (PFS) rates after tumor removal were estimated with Kaplan-Meier method followed by log-rank test for evaluating their differences that stratified by BMI (<25, 25~30, ≥30) or diabetes (suffer/not suffer). Multivariate Cox proportional hazards regression model was used to uncover the relationship between common clinical pathological features and prognosis of breast cancers.
Results: Compared with UBC, patients with BBC tended to be with higher BMI (P = 0.000) and larger percentage of diabetes ( P = 0.035). The Kaplan-Meier survival analysis indicated that higher BMI complicated by diabetes and negative estrogen receptor significantly decreased the survival rate of BBC patient ( P < 0.05). In addition, diabetes was closely associated with OS or PFS in metachronous BBC ( P = 0.006). The result of multivariate Cox proportional hazards regression model showed that BMI and diabetes were two independent prognostic factors for OS.
Conclusion: Obesity and diabetes have a significant impact on the survival of the patients with BBC.
Keywords: bilateral breast cancer; body mass index; diabetes; overall survival; progression-free survival.
© 2019 Wiley Periodicals, Inc.