Prognostic Importance of Vitamins A, E and Retinol-binding Protein 4 in Renal Cell Carcinoma Patients.

Aim: To assess the prognostic importance of serum levels of retinol, retinol-binding protein 4 (RBP4) and vitamin E at the time of diagnosis in patients with renal cell carcinoma (RCC). Patients and Methods: In this prospective study, in a cohort of 102 renal cell carcinoma patients, relationships between serum levels of the aforementioned markers and recurrence-free survival (RFS), overall survival (OS), as well as cancer-specific survival (CSS), were evaluated. The vitamin A and vitamin E levels were determined by high-performance liquid chromatography (HPLC), while the RBP4 level by enzyme-linked immunosorbent assay (ELISA). Results: The median follow-up period was 39 months. Renal cell carcinoma recurred in 9 patients; 23 patients died with 12 of them from RCC. The preoperative vitamin E level was associated to RFS (p=0.02). We found a significant relationship between OS and the level of RBP4 (p=0.002), retinol (p=0.037) and vitamin E (p=0.007). The CSS period was significantly associated with the level of RBP4 (p=0.0001) and retinol (p=0.0003). Patients with an RBP4 level less than 21.0 mg/l at the time of diagnosis had a 13.5-times higher risk of death due to RCC progression; this risk was up to 7.7-times higher with vitamin A levels under 0.52 mg/l. Conclusion: Low levels of vitamin A, E and RBP4 at the time of RCC diagnosis are associated with a poorer prognosis after surgery.