Assessment of albumin and overall survival in advanced non-small cell lung cancer patients with anlotinib treatment using generalized additive model: A retrospective cohort study

Albumin is believed to be associated with the prediction of various cancers. This retrospective cohort study aimed to explore the non-linear relationship between albumin level and overall survival (OS) in advanced non-small cell lung cancer (NSCLC) patients with anlotinib therapy, utilizing the Generalized additive model (GAM) approach. Specifically, we investigated the potential non-linear associations that might not be captured by conventional linear analyses. A retrospective cohort of 211 patients undergoing anlotinib treatment for advanced NSCLC was included in this study. A wide range of albumin levels was considered, and the GAM method was applied to account for potential confounding clinical variables and unveil the non-linear relationship between albumin and OS. A non-linear relationship with inflection points of 40 g/L and 48 g/L was detected between albumin level and OS after adjusting for potential confounders. The hazard ratio (HR) of the left, middle and right of the inflection points were 0.95 (95 % confidence interval [CI], 0.87 to 1.04, p = 0.2819, n = 71), 0.75 (95 % CI, 0.64 to 0.89, p = 0.0007, n = 133) and 2.79 (95 % CI, 1.39 to 5.61, p = 0.0039, n = 7), respectively. The findings indicate a negative correlation between albumin level and OS when albumin level was between 40 g/L and 48 g/L. For every unit increase in albumin, there was a 25 % reduction in the risk of death. Subgroup analysis revealed that the negative relationship was enhanced with blood urea nitrogen (BUN) level increase and diminished with D-dimer increase. The relationship between albumin level and OS was non-linear. Albumin level is an independent prognostic factor for OS. In addition, BUN level and D-dimer level could modify the effect of albumin level on the risk of death in advanced NSCLC patients treated with anlotinib.