Evaluation of Plasmatic Kisspetin-10 as a Biomarker for Malignancy and Subtype Differentiation in Small Renal Tumours

OBJECTIVE: To evaluate Kisspeptin-10 (Kiss-10) in patients with small renal tumours (SRTs) and controls. MATERIAL AND METHODS: Kiss-10 was measured in preoperative plasma samples in a cohort of 143 patients with unilateral renal tumours smaller than or equal to 4 cm and 40 age-matched controls by a competitive ELISA test kit. The cohort of patients included 56 patients with clear cell renal cell carcinoma (ccRCC), 43 with papillary RCC (pRCC), 12 with chromophobe RCC (chRCC) and 32 with oncocytomas. RESULTS: Kiss-10 was detected in all patients and controls. SRT patients revealed significantly higher Kiss-10 levels than controls (mean value 10.04 vs. 6.37 pmol/l, p < 0.001). In SRT patients, Kiss-10 was detected at significantly different concentrations between the subgroups (p = 0.021). The highest concentration was observed in those with oncocytomas (11.50 pmol/) followed by chRCC, pRCC and ccRCC patients (9.89, 10.01 and 9.25 pmol/l, respectively). Receiver operating characteristic curve analyses revealed an area under the curve (AUC) of 0.82 for the comparison of all tumours vs. controls (p < 0.001) and an AUC of 0.671 for all malignant tumours vs. oncoytomas (p = 0.003). CONCLUSION: This study shows that Kiss-10 levels are significantly altered by malignancy and tumour subtypes even in patients with SRTs. Kiss-10 therefore deserves further attention as a plasmatic biomarker for renal tumours.