Body mass index-based inflammation index is a promising prognostic predictor in older adult cancer patients

Older patients with cancer often have a worse prognosis than the general cancer patient population due to decreased immune responses, chronic inflammation status, and malnutrition. The present study aimed to develop a novel body mass index (BMI)-based inflammation index and investigate its prognostic significance in older patients with cancer. This multicenter prospective study totally included 2376 cancer patients aged 65 years or older. Concordance index (C-index) and receiver operating characteristic (ROC) curves were applied to compare the prognostic value of various BMI-based inflammation indices. The overall survival (OS) was calculated and compared using the Kaplan–Meier method generated by the log-rank test. A Cox proportional hazard regression model was performed to identify independent predictors associated with OS. Subgroup analysis was used to explore the discriminative performance in different populations. The second outcomes included short-term survival, malnutrition and cachexia. We recorded 1112 death cases during a median follow-up of 17.43 months. Both the area under ROC curves and the C-index of the BMI to C-reactive protein/lymphocyte ratio (BCLR) were higher than other inflammation indices. There was a significant L-shaped association between BCLR and all-cause mortality in older patients with cancer (P < 0.001). A low BCLR was significantly associated with shortened OS and served as an independent risk factor for survival in older patients with cancer (hazard ratio = 1.51, 95% confidence interval = 1.32–1.73, P < 0.001). In the subgroup analysis, a low BCLR was an independent risk factor for prognosis inpatients with lung (HR = 1.40, 95%CI = 1.13–1.73, P = 0.002), upper gastrointestinal (HR = 1.32, 95%CI = 1.01–1.73, P = 0.041), hepatobiliary and pancreatic (HR = 1.78, 95%CI = 1.10–2.88, P = 0.020) and colorectal cancer (HR = 2.24, 95%CI = 1.57–3.18, P < 0.001). In addition, the prognostic value of low BCLR was also confirmed in underweight, normal as well as overweight and obesity populations. Multivariate logistic regression models showed that a low BCLR was an independent risk factor associated with short-term mortality, malnutrition and cancer cachexia in older patients with cancer. Two internal validation cohorts at a ratio of 7:3 confirmed the results of our study. The BCLR is a promising indicator to assess nutritional-inflammatory status in older patients with cancer and can be used to identify patients with worse prognoses.