Gastrointestinal Cancers (GICs) European Journal of General MedicineOriginal Article Eur J Gen Med 2014; 11(2): 94-98 DOI : 10.15197/sabad.1.11. 46 Eur J Gen Med 2014;11(2): 94-98 Increased sister chromatid exchange in gastrointestinal cancers 95 MATERIALS AND METHODSThis study was conducted at Düzce University Medical Faculty, Department of Medical Genetics, Düzce, Turkey. The study groups consisted of 15 GIC patients (2 esophagus, 6 stomach, 6 colon and 1 rectum), 13 relatives and 15 healthy subjects. Approved ethical certificate was obtained from local ethics committee, and written informed consents of the studied cases were obtained. Age, gender, smoking and alcohol consumption status and tumor markers (alpha-fetoprotein, AFP, carcinoembryonic antigen-CEA, carcinogenic antigen (CA) 125, CA19-9, CA15-3) were recorded. Two milliliters of venous blood was drawn using Na-heparinized syringes from each case. Replication Index was calculated by following formula.RPI: R1 + (R2x2) + (R3x3) / R1 + R2 + R3Mitotic index (MTI) was calculated by following formula. MTI: metaphase/metaphase+lymphocyte count Statistical analysisThe frequency of SCE per metaphase in groups was compared by Kruskal Wallis. Mann-Whitney U test was also used. Relationships between parameters were evaluated with the Spearman's correlation analysis. Qualitative data were compared using Chi-square test. Results with 95% confidence interval and p<0.05 were considered significant.