Relation of Colorectal Carcinogenesis and Obesity Through Insulin Like Growth Factor Axis and Gene Polymorphism in Egyptians, AYMAN YOSRY, MOHAMAD YOUSEF, MOHAMAD SALAH, MOHAMAD S. MARIE, HEBA OMAR, SHERIF HAMDY, OLFAT SHAKER and DALIA OMRAN
Abstract
Background and Aim: Insulin pathway plays a role in mediation of colorectal cancer (CRC). In this study, we investigated the association between CRC and obesity in Egyptians through assessment of single nucleotide polymor-phism (SNP) in insulin-like growth factor-1 (IGF-I) gene. We also studied serum levels of IGF-1in Egyptian CRC patients with different BMI.
Methods: This prospective study included 66 CRC patients and 30 healthy individuals, for whom body mass index (BMI) was estimated, patients and controls were categorized into overweight or obese as one group and average weight as another group. Serum levels of IGF-1 were assessed by ELISA and SNP in IGF-I gene at rs6214C/T, rs6220 T/C & rs35767 C/T were studied by PCR- RFLP.
Results: Serum level of IGF-1 was significantly lower in CRC average weight and overweight cases. IGF-1 can predict CRC at a cutoff 154 ng/ml with 87.5% sensitivity and 72.6 specificity. IGF-1 rs6214 CT and TT (T Allele) genotypes were associated with a significantly increased risk of CRC.
Univariate logistic regression showed that CRC signifi-cantly decreases by 0.14 for each one unit increase in IGF1.
Conclusion: BMI could be considered as effect modifier for CRC risk. IGF-1 SNP rs6214 (TT and CT) was significantly associated with colorectal cancer risk regardless of the BMI.