Short-term BMI trajectories as a prognostic predictor in patients with pancreatic cancer

Objective While numerous studies have examined the association between body mass index (BMI) and cancer prognosis, most have only captured BMI at a single time point. Whether BMI trajectories are linked to the prognosis of pancreatic cancer remains unclear. This study aimed to investigate the relationship between short-term BMI trajectories and clinical outcomes in patients with pancreatic cancer. Methods A retrospective study was performed on 200 pancreatic cancer patients who admitted to our hospital from January 1, 2017 to December 31, 2021. BMI 1 (BMI of patients diagnosed with pancreatic cancer 1 year before), BMI 2 (BMI of the patient at diagnosis of pancreatic cancer), BMI 3 (BMI of patients 6 months after diagnosis of pancreatic cancer), BMI 4 (BMI 1–BMI 2), BMI 5 (BMI 3–BMI 2) and BMI 6 (the longitudinal BMI trajectory) were recorded. Clinical-pathological characteristics, oncologic outcomes, progression free survival (PFS) and overall survival (OS) were collected. The prognostic significance was determined by Kaplan-Meier analysis, Cox proportional hazards and restricted cubic spline regression models. Results We found that changes in BMI may be a predictor of pancreatic cancer survival. The results of the multivariate analysis of factors influencing the pancreatic cancer OS showed that BMI 4 ≥1.3 (HR: 1.69, 95% CI: 1.19–2.41, P = 0.004), BMI 5 <−0.3 (HR: 3.05, 95% CI: 2.01–4.65, P < 0.001) and BMI 6 (patients from normal BMI to low BMI, HR: 2.51, 95% CI: 1.09–5.77, P = 0.031; patients from high BMI to normal BMI, HR: 2.01, 95% CI: 1.09–3.70, P = 0.025) indicated higher mortality rate. Conclusion This study confirms that short-term BMI trajectories before and after diagnosis, as well as early during treatment, are independent prognostic factors for both overall survival and progression-free survival in pancreatic cancer patients. Particular attention should be paid to patients who are normal-weight at diagnosis but transition to a low-BMI category shortly after treatment, as they face the highest mortality risk.