The Value Of Serum Cysteine Protease Inhibitor CST1 In Screening Early Colorectal Cancer

Objective Colorectal cancer is a common malignant tumor of digestive tract,which has become one of the five most common malignant tumors in China.Most cases of colorectal cancer patients are found in the middle and late stage,leading to a small surgical opportunity,poor prognosis.And most colorectal cancer is from colorectal polyp malignant transformation,but indicators be used for early colorectal cancer screening are still not ideal.Therefore,it is particularly important to find a new indicator that can screen for early colorectal cancer.It has been found that the serum cysteine protease inhibitor CST1 is highly expressed in human intestinal malignancies.In order to obtain an efficient screening index for early colorectal cancer,this study studied the expression characteristics of serum CST1 in colorectal polyps and cancers,and discussed its value in screening early colorectal cancer and colorectal polyps.Methods We prospectively collected all patients who underwent electronic colonoscopy from January 2018 to December 2018 in qianfoshan hospital of Shandong Province.Through our inclusion and exclusion criteria,we finally collected 206 patients.The study included59 patients in the normal control group,74 patients with low grade polyps of colorectal cancer,17 patients with high grade polyps and 56 patients with colorectal cancer.Patients were divided into two groups according to their pathological cancer: the low-differentiation group(n=14)and the medium to high differentiation group(n=42).General data of all patients including gender and age were collected,basic diseases including hypertension,hyperlipidemia,hyperglycemia,personal history of smoking and drinking,as well as laboratory examinations including carbohydrate antigen 199(CA199),carcinoembryonic antigen(CEA)and fecal occulting blood(g FOBT).The expression of serum CST1 in different groups was compared.The ROC curve was used to determine the critical values of CST1,CEA and CA199 in different groups through the most approximate exponent,and the sensitivity and specificity of each indicator for screening colorectal cancer were compared.Finally,the optimal screening strategy for colorectal cancer was evaluated by calculating the combination of the indicators.Results 1.Serum CST1 expression was increased in low grade colorectal polyps,high grade colorectal polyps and colorectal cancer.According to the mean change trend of CST1,CEA and CA199 in each group,it was found that CST1 increased more significantly in the colorectal low-grade polyp group and the high-grade polyp group than in other tumor indicators.2.Serum CST1 level is associated with colorectal cancer,and is strongly correlated with colorectal lesions,and is superior to other screening indicators such as CEA,CA199,and g FOBT.Therefore,CST1 is of great significance in the prediction of early colorectal cancer.3.Multiple indicators combined screening for colorectal cancer,in terms of sensitivity,CST1 is combined with CEA,CA199,g FOBT > CEA with CA199,g FOBT > CST1 with CA199,g FOBT = CST1 with CEA,CA199(90.41%,86.30%,84.93%,84.93%).In specificity,CST1 is combined with CA199,g FOBT > CST1 with CEA,CA199 > CEA with CA199,g FOBT > CST1 with CEA,CA199,g FOBT(59.40%,58.64%,49.62%,45.86%).Conclusion 1.The expression level of serum CST1 in low grade colorectal polyps,high grade polyps and colorectal cancer was significantly higher than that in the normal group.With the aggravation of the lesion,the expression level of serum CST1 was higher and higher.Therefore,CST1 has the value of screening early colorectal cancer and colorectal polyp.2.The value of serum CST1 in screening early colorectal cancer is better than CEA,CA199 and fecal occult blood.3.Serum CST1 combined with CEA,CA199 and g FOBT has higher screening value in early rectal cancer.