Abstract
BACKGROUND: Immunotherapy functions by leveraging immunoregulation drugs to bolster the immune system's capacity to identify and eliminate cancerous cells. In contrast to radiotherapy and chemotherapy, immunotherapy exhibits diminished side effects, heightened efficacy, and prolonged survival rates. Nevertheless, meticulous exploration into the determinants governing the advantageous effects of immunotherapy among patients who have previously undergone multiple prior therapies has yet to be conducted. Albumin (ALB) as a nutritional indicator has not been thoroughly studied for its prognostic effect on efficacy or survival. This study aims to identify factors that influence treatment outcomes among patients undergoing third-line or later immunological therapies. METHODS: A cohort of 250 lung cancer patients undergoing toripalimab or tislelizumab immunotherapy was the focal point of data collection. The determination of the median value facilitated the establishment of a cut-off point, enabling the categorization of continuous variables. After data collection, a series of statistical analyses of various clinical factors at baseline were performed, including nonparametric tests, logistic regression, and Cox proportional risk modeling. The last follow-up was in May 2022. The primary study endpoint was overall survival (OS). RESULTS: A total of 250 patients were enrolled in the study, of which 129 patients received first- or second-line immunotherapy and 121 patients received third-line or subsequent immunotherapy. According to Cox multifactor regression analysis, in patients receiving either first- or second-line therapy, the ALB level exhibited negligible prognostic relevance (P>0.05). However, in patients subjected to immunotherapy beyond the second line, the ALB level manifested significant prognostic importance (P=0.039). Notably, patients demonstrating elevated ALB levels achieved a higher disease control rate (DCR) (70.0% vs. 52.5%, P=0.05) and displayed a tendency towards a heightened objective response rate (ORR) (20.0% vs. 16.4%, P=0.61) in comparison to those with lower ALB levels. CONCLUSIONS: Among patients undergoing immunotherapy in the third line or subsequent treatment phases, elevated ALB levels in baseline correlated with DCR and OS. Thus, the pre-immunotherapy ALB level emerges as an autonomous predictor of OS in patients subjected to third- or later line immunotherapy interventions.