Urinary NGAL and KIM-1: potential association with histopathologic features in patients with renal cell carcinoma.

Purpose: NGAL and KIM-1 are suggested to play a key role in the carcinogenesis and progression of renal cell carcinoma. Attention is currently focused on the potential use of the urinary level of NGAL and KIM-1(uNGAL and uKIM-1, respectively) in making an early diagnosis, establishing a prognosis and determination of the histologic characteristics.

Methods: Forty-six patients underwent surgical treatment for renal lesions (n = 37) and for non-functioning kidney (n = 9). uNGAL and uKIM-1 levels were evaluated for clear cell, papillary and chromophobe subtypes of renal cancer patient and also for the control patients. The concentrations were determined by ELISA.

Results: uNGAL and uKIM-1 in the control group were not significantly different from those of the patients with kidney cancer. There was no association between tumor size or histologic grade and the uNGAL and uKIM-1 levels. All patients with papillary type RCC had KIM-1 level below 2 ng/mgUcr and uNGAL concentration above 50 ng/mgUcr. Using the same threshold values enables prediction of 100% of patients with chromophobe subtype; 91.6% of the patients with clear cell histology have uNGAL concentration below 50 ng/mgUcr and KIM-1 concentration below 5 ng/mgUce.

Conclusion: Combined analysis of uNGAL and uKIM-1 allowed high prediction rate of the histologic subtype of the radiographic-detected masses among cases with kidney cancer. These biomarkers may enable to select the proper therapeutic agents in cases with metastatic disease without the need of pretreatment biopsy.