Prognostic Significance of the Combined Albumin-To-Alkaline Phosphatase Ratio (AAPR) and Haemoglobin–Albumin–Lymphocyte–Platelet (HALP) Score in Patients with Metastatic Renal Cell Carcinoma Treated by Targeted Therapy: A New Prognostic Combined Risk

<b>Background/Objectives:</b> Renal cell carcinoma (RCC) accounts for 2-3% of all cancers, with approximately 25% of patients being detected at the metastatic stage. This study aimed to determine the prognostic significance of co-evaluating two risk parameters: one, the HALP score based on haemoglobin, albumin, lymphocyte, and platelet counts, and the other, albumin-to-alkaline phosphatase ratio (AAPR) in patients with metastatic RCC treated with targeted therapy. <b>Methods:</b> This retrospective cohort study included 147 patients with metastatic RCC. The HALP score and AAPR values were calculated from pre-treatment blood test results, and followingly, the cut-off value was determined by using ROC analysis. Patients were categorised into three groups with a low, moderate or high combined risk score based on this cut-off value. The effect of these risk groups on survival was evaluated. <b>Results:</b> The mean age of patients was 64.1 ± 11.9. The median follow-up time was 38.3 months, and the mortality rate was 53.7% in all groups. Kaplan-Meier survival analysis showed a statistically significant difference between the combined scores of the risk groups: the median survival time was 51.6 months in the low-risk group, 20.7 months in the medium-risk group, and 10.4 months in the high-risk group (<i>p</i> < 0.001), with 5-year survival rates being 38.8% in the low-risk group, 30% in the intermediate-risk group, and 19% in the high-risk group. When compared to the low-risk group, Cox regression analysis revealed that the mortality risk, i.e., HR (hazard ratio), was 2.42 times higher in the intermediate-risk group and 3.76 times higher in the high-risk group. A nephrectomy operation decreased the mortality risk (HR = 0.24) by 4.16 times. <b>Conclusions:</b> This new combined risk scoring, obtained from co-evaluating the HALP score and AAPR, was found to be an independent prognostic factor in metastatic RCC patients. This combined risk scoring is expected to help clinicians in treatment decisions.