FABP7: A Potential Diagnostic and Prognostic Biomarker for Clear Cell Renal Cell Carcinoma.

Abstract

Background/aim: Renal cell carcinoma (RCC) is highly heterogeneous, with distinct patient management between clear cell RCC (ccRCC) and non-ccRCC groups. Previous bioinformatics and machine learning techniques identified fatty acid binding protein 7 (FABP7) as a potential ccRCC biomarker. However, FABP7 expression studies between ccRCC and non-ccRCC were incomplete. This study aimed to assess FABP7 as a biomarker for distinguishing between ccRCC and non-ccRCC tissue samples.

Patients and methods: FABP7 expression was evaluated via immunohistochemical staining in 58 RCC cases, including 43 ccRCC and 15 non-ccRCC cases. Staining results were interpreted using H-scores; scores above the cut-off were deemed positive. The correlation between FABP7 expression and clinicopathological RCC features was investigated.

Results: FABP7 positivity was 48.8% in ccRCC and only 13.3% in non-ccRCC cases, with weak positivity in non-ccRCC tissues. FABP7 expression significantly differed between ccRCC and non-ccRCC (p<0.05). This finding was confirmed in a TCGA dataset. However, FABP7 expression was not correlated with other RCC clinicopathological features in our dataset. TCGA results linked FABP7 expression to tumor stage and disease-free survival in patients with ccRCC.

Conclusion: This study preliminarily evaluated FABP7 as a differential diagnostic biomarker in RCC subtyping, showing higher expression in ccRCC than non-ccRCC. FABP7 may serve as a potential diagnostic and prognostic biomarker for ccRCC.