GSTM1 and colorectal cancer: Based on the quantitative FIT using the cutoff concentration of 100 ng Hb/mL buffer, the previous study in Taiwan showed that the positive rate of FIT for the first and subsequent round were 4.0% and 3.8%, respectively [15], and overall positive predictive values for advanced adenoma and colorectal cancer were 13.2% and 6.8%, respectively [17].