Biomarkers in blood and saliva to screen fragile patients with solid tumors : a systematic review of the literature

Abstract

Objective Frailty is a multidimensional syndrome. It necessitates individualized therapies, particularly in oncological surgery, due to the increased risk of perioperative complications in frail patients. Recent literature suggests that biomarkers in saliva and blood may serve as valuable tools in clinical practice. To identify effective methods for screening frail patients with solid tumors using appropriate biomarkers, we conducted a systematic review of the literature. Methods A comprehensive literature search was conducted in Pubmed, Cochrane Library and Web of Science from the inception until 5th February 2024. Our inclusion criteria mandated a clear definition of frailty and a significant association with specific biomarkers in saliva or blood in patients with solid tumors. Results From 2604 screened abstracts 17 publications were included in the analysis. The results regarding biomarkers that were significantly associated with frailty, varied across the studies. Regarding frailty instruments, the G-8 geriatric screening tool and the Fried scale were the most frequently used tools. Both, elevated levels of CRP and IL-6 correlated with frailty in some research, while other studies identified links with the neutrophil-lymphocyte ratio, amino acids, or immune cells. Notably, no salivary biomarkers for frailty were found in patients with solid tumors. Conclusion There are currently no established blood or salivary biomarkers for frailty. However, an elevated inflammatory status and related markers are often significantly correlated with frailty in solid tumor patients. These findings highlight the potential to develop suitable biomarkers for frail oncology patients, emphasizing the need for further research in this area.