Expression, Significance, and Impact on Survival of Fatty Acid Binding Proteins 4 and 7 in Colorectal Cancer: A Tissue Microarray Study

Background.Colorectal cancer (CRC) remains a major cause of cancer-related morbidity and mortality worldwide.Recently, the pathogenesis of CRC among other cancer types has been linked to lipid metabolism.Fatty acid-binding proteins (FABPs) are a protein-family expressed in multiple tissues and play a crucial role in lipid metabolism.A few recent studies have examined FABPs role in CRC.Our aims are to explore the immunohistochemical expression of fatty acid binding proteins (FABP) 4 and 7 in colorectal cancer, and correlate their expression levels with clinical, histopathological features, and survival.Methods.A retrospective review of colorectal cancer biopsies over a 5-year period was conducted in our institute.Clinical and histological data were collected.Immunohistochemical staining for FABP 4 and 7 was performed using microarray and their expression was evaluated using the Histologic score (HS).The correlations between the expression of FABP 4 and 7 and clinicopathological parameters were determined by Fisher's exact test.The impact of the expression on the overall survival was determined using Kaplan-Meier survival analysis.Results.125 CRC tissue biopsy blocks were included.Median follow-up time was 35 months.High FABP4 expression was observed in 107 (85.60%).For FABP7, only 8.8% of cases (11/125) showed high expression.Co-expression of FABP4 and FABP7 occurred in 11 cases (8.8%).FABP7 expression correlated with age (p = 0.001).The median overall survival of patients with high expression of FABP4 was 43.00 ± 3.01 months, whereas patients showing low/negative expression reported a survival of 24.00 ± 6.24 months(p =0.041).No statistically significant association between FABP7 high expression and the overall survival was detected (Log-Rank test, p = 0.086).Conclusion.FABP4 expression in CRC is higher than that of FABP7.FABP7 expression levels negatively correlate with the age of CRC patients.FABP4 expression is associated with a better survival in CRC.No significant association between FABP4 and 7 with tumor grade, stage, or other clinicopathological criteria has been found in this study.