Evaluation of quantitative and qualitative fecal occult blood reagent in colorectal cancer screening

Objective To investigate the application effects of quantitative and qualitative fecal occult blood (FOB) reagent in colorectal cancer screening.Methods With the platform of colorectal cancer screening for early diagnosis and treatment,the original screening methods and process were not changed,individuals underwent colorectal cancer screening,aged from 40 to 74 years old,from four villages of Haining City in Zhejiang Province were selected as study objects.Initial screening included medical history questionnaire and FOB test.The first stool samples were examined both with quantitative and qualitative FOB test,one week later the second samples were detected with qualitative FOB test.History positive or once of any type of reagent positive was considered as initial screening positive.The individuals with initial screening positive received fine screening (colon endoscope examination).The effects evaluation included the positive rate of FOB,intestinal lesion detection rate,sensitivity,specificity and Youden index.The health economic analysis was calculated.Chi-square test was performed for comparisons between the two groups.Results A total of 8 427 history survey were completed,the positive rate of history was 8.48％(715/8 427) ; 6 644 underwent quantitative detection of FOB and the positive rate was 4.44 ％ (295/6 644) ; qulitative test was conducted in 12 633 samples were conducted and the positive rate was 2.56 ％ (324/12 633),the difference was statistically significant (x2 =49.27,P＜ 0.01).A total of 854 individuals with initial screening positive underwent electronic colonoscopy examination,the total intestinal lesion detection rate was 22.72％ (194/854),of which the intestinal lesion detection rate of quantitative group was 34.55％ (66/191),and that of qualitative group was 17.73％ (36/203),the difference was statistically significant (x2 =14.53,P＜0.01).The detection rate of both quantitative and qualitative test positive was 43.75 ％ (14/32).The colorectal cancer detection rates of quantitative and qualitative FOB test were 3.66％ (7/191) and 0.99％ (2/203),advanced adenoma detection rates were 8.38 ％ (16/191) and 5.91％,there were no significant differences (x2 =2.08 and 0.96,both P＞0.05).The sensitivity of quantitative and qualitative FOB test in advanced adenoma and cancer detection rate was 45.10％ and 27.45％,respectively.The average cost of quantitative and qualitative FOB test in intestinal lesions detection was 5 874.50 and 1 432.14 yuan.Conclusion The effects of quantitative FOB test in colorectal cancer screening was better than that of qualitative reagent,however on the cost of screening,the former was 4.10 times of the latter. Key words: Colorectal neoplasms;  Mass screening;  Feces;  Occult blood;  Indicators and reagents; Cost-benefit analysis