Time-Dependent Changes Provide Better Prognostic Insights than Static Measurements of BMI in Gastric Cancer Patients

In gastric cancer (GC) patients, malnutrition is associated with a worse prognosis. Decreases in body mass index (BMI) can reflect malnutrition. Here, we determined whether preoperative time-dependent changes (Δ/day) in BMI provide better prognostic insights than single point-in-time measurements of BMI. A single-center retrospective analysis of 140 GC patients was performed. BMI was measured at both the initial surgical visit and then again at the time of hospitalization for surgery. ΔBMI/day was determined. Associations with time to surgery, intraoperative blood loss, tumor stage, and survival were determined. ΔBMI/day was strongly associated with time to surgery (P = 0.001), magnitude of intraoperative blood loss, tumor stage, progression-free survival (PFS), and overall survival (OS) (all Ps <0.001). In multivariable Cox analyses adjusted for age, sex, Eastern Cooperative Oncology Group Performance Status, pathological stage, surgical approach, blood loss, time-to-surgery, and static BMI measurements, large ΔBMI/day was associated with worse PFS (hazard ratio 2.81, 95% confidence interval 1.07-7.42, P = 0.037) whereas static measurements of BMI at the time of the initial visit or surgery were not independently associated with PFS. ΔBMI/day was not independently associated with OS. In conclusion, preoperative changes in BMI/day provide better prognostic insights, particularly for PFS, compared to measurements of BMI at a single point in time.