G8, CARG, Frailty, and Nutritional Markers in Predicting Chemotoxicity

Background: Aging is associated with decreased physiological reserves, making elderly cancer patients more vulnerable to chemotherapy toxicity (CT). Traditional performance scales like ECOG may be insufficient for treatment decisions. Tools such as G8, Clinical Frailty Scale (CFS), and the Cancer and Aging Research Group (CARG) score are practical screening instruments recommended by ASCO and SIOG, yet their combined predictive accuracy for CT and granulocyte colony-stimulating factor (G-CSF) usage remains underexplored. Objectives: This prospective study aims to evaluate the predictive performance of the G8, CARG, and Frailty scales-alone and in combination with nutritional biomarkers (albumin, prealbumin, hemoglobin, CRP)-in forecasting chemotherapy-related toxicity and G-CSF need. It also investigates the correlation between these geriatric assessment tools and Mini Nutritional Assessment (MNA) scores. Methods: The study will be conducted at Çanakkale University Medical Faculty Oncology Outpatient Clinic. Patients aged 65 and above with a planned chemotherapy regimen will be recruited. Before the first chemotherapy cycle, patients will undergo G8, CARG, Frailty, and MNA assessments. Nutritional biomarkers will be extracted from pre-treatment routine lab tests. Chemotherapy toxicity and G-CSF requirement will be monitored across treatment cycles. ROC, correlation, and regression analyses will be conducted to evaluate predictive validity.