Screening patients for colorectal cancer between ages 55 and 64 could reduce colon cancer mortality by 43 per cent, a study in the Lancet has found. The randomised controlled trial, which followed up 170,432 UK patients for 11 years, found a one-off flexible sigmoidoscopy screen cut mortality by 43 per cent compared with the control group. The incidence of colorectal cancer was also slashed by a third thanks to early intervention, while the incidence of cancer in the rectum or sigmoid colon was reduced by 50 per cent. According to The Lancet study, the number of patients that needed to be screened to prevent one case of colorectal cancer was 191, with 489 patients needed to be screened to prevent one death.