OBJECTIVETo evaluate the sensitivity and specificity of optimized sequential screening program of colorectal cancer, and provide evidence for the further optimization of colorectal cancer screening program.

METHODSUsing cluster sampling method, 4 administrative villages were selected from Jiashan county as a census district in 2011 to 2013. Volunteers of 40 to 74 years old in the census were recruited, and tested by both optimized sequential screening (including questionnaire survey and fecal occult blood test) and colonoscopy for colorectal cancer. Sensitivity and specificity of different screening methods were calculated, respectively.

RESULTSA total of 2 607 volunteers took both simultaneously screening and colonoscopy at the same time. 20 colorectal cancer cases, 85 advanced adenoma cases, 271 non-advanced adenomas cases, and 141 non-adenomatous polyps cases were detected. Sensitivity of optimized sequential screening for colorectal cancer, advanced adenomas, and non-advanced adenomas were 70.0% (14/20) , 57.6% (49/85) and 36.5% (99/271) , specificity was 68.7% (1 776/2 587) , 69.2% (1 746/2 522) and 68.9% (1 610/2 336) , respectively. Sensitivity of the fecal occult blood test of colorectal cancer, advanced adenomas and non-advanced adenomas were 70.0% (14/20) , 47.1% (40/85) and 26.6% (72/271), specificity was 79.4% (2 053/2 587), 79.9% (2 014/2 522) and 79.6% (1 860/2 336). The sensitivity of fecal occult blood test and those of optimized sequential screening for colorectal cancer, advanced adenomas was not significant (χ(2) = 0.00, 1.91, all P values > 0.05). Sensitivity of questionnaire survey of colorectal cancer, advanced adenomas and non-advanced adenomas were 10.0% (2/20), 14.1% (12/85), 12.9% (35/271), specificity was 87.6% (2 266/2 587), 87.7% (2 211/2 522), 87.6% (2 046/2 336). There were no significant difference between non-advanced adenomas. The sensitivity of advanced adenomas and non-advanced adenomas showed no significant decline when the following six term were removed from screening programs: chronic diarrhea, chronic constipation, mucus or bloody history, history of chronic appendicitis or appendectomy surgery, chronic cholecystitis or gallbladder surgery, adverse events in the history of life, while the sensitivity of colorectal cancer remained nearly the same 70.0% (14/20), 52.9% (45/85), 31.4% (85/271) (χ(2) = 0.38, 1.61, all P values > 0.05).

CONCLUSIONCurrent optimized sequential screening programs for colorectal cancer in China have a high sensitivity and specificity. However, further optimization is viable and necessary.