Abstract
OBJECTIVE: The aim of this study was to determine the association between weight change patterns and survival outcomes of women with endometrial cancer. METHODS: This retrospective study examined surgically-staged endometrial cancer cases with available weight information between 1999 and 2013 (n = 665). Proportional body mass index (delta-BMI) change at 6 months, 1 and 2 years after hysterectomy was compared with baseline BMI and correlated to patient demographics, tumor characteristics, treatment type, and disease-free survival (DFS) and overall survival (OS). RESULTS: Mean BMI was 35.6, and 69 % of cases were obese. At 6 months, 1 and 2 years after surgery, 39.1, 51.6, and 57.0 % of the study population, respectively, gained weight compared with pre-treatment baseline. In univariate analysis, 6-month delta-BMI change was significantly associated with DFS and OS, demonstrating bidirectional effects (both p < 0.001): 5-year rates, ≥15.0 % delta-BMI loss (33.5 and 59.1 %), 7.5-14.9 % loss (67.3 and 70.0 %), <7.5 % loss (87.8 and 95.7 %), <7.5 % gain (87.2 and 90.3 %), 7.5-14.9 % gain (64.6 and 67.6 %), and ≥15.0 % gain (32.5 and 66.7 %). In multivariable analysis controlling for age, ethnicity, baseline BMI, histology, grade, stage, chemotherapy, and radiotherapy, 6-month delta-BMI change remained an independent prognostic factor for DFS and OS (all p < 0.05): adjusted hazard ratios, ≥15 % delta-BMI loss (3.35 and 5.39), 7.5-14.9 % loss (2.35 and 4.19), 7.5-14.9 % gain (2.58 and 3.33), and ≥15.0 % gain (2.50 and 3.45) compared with <7.5 % loss. Similar findings were observed at a 1-year time point (p < 0.05). Baseline BMI was not associated with survival outcome (p > 0.05). CONCLUSION: Our results demonstrated that endometrial cancer patients continued to gain weight after hysterectomy, and post-treatment weight change had bidirectional effects on survival outcome.