Colonoscopy Shows Strong Effect in Reducing CRC Incidence and Mortality

A prospective cohort study confirmed the value of screening colonoscopy in reducing the incidence and mortality from colorectal cancer (CRC), but also suggested that more effective and less invasive means of preventing and detecting CRC in the proximal colon are needed.

The researchers noted that while multiple randomized controlled trials have demonstrated that  flexible sigmoidoscopy is associated with significant reductions in the incidence and mortality of CRC in the distal colon and rectum, such evidence for the association of colonoscopy with impacts on detection of CRC in the proximal colon has been lacking. In this study, the investigators sought to determine if there is such an association between colonoscopy and CRC incidence and mortality in not only the distal colon and rectum, but also in the proximal colon.

The researchers collected baseline data during the period 2000-2002 for 9207 participants aged 50 to 75 years with no history of CRC. These data were updated at intervals of 2, 5, 8, and 17 years. Through linkage to a cancer registry in the state of Saarland, Germany, the authors obtained information on CRC incidence and mortality through 2018, which they assessed by Cox proportional hazard models.

During the 17.2-year median follow-up period, 268 participants were diagnosed with CRC and 98 died. The researchers concluded that screening colonoscopy was associated with a strong reduction in the incidence of CRC (adjusted hazard ratio [aHR] 0.44, 95% confidence interval [CI] 0.33–0.57) and mortality (aHR 0.34, 95% CI 0.21–0.53), although the reduction was more pronounced for distal than for proximal cancer.

“Our results underline the large potential of screening colonoscopy to prevent cancer in the distal colon and rectum and to reduce mortality from these cancers and even total cancer mortality,” the authors wrote. At the same time, however, they also underline the need of further efforts toward more effective prevention of cancer in the proximal colon.”

--Rebecca Mashaw

Reference:

Guo Feng, Chen C, Holleczek B, Schöttker B, Hoffmeister M, Brenner H. Strong reduction of colorectal cancer incidence and mortality after screening colonoscopy: Prospective cohort study from Germany. Am J Gastroenterol. 2021;116(5): 967-975

doi: 10.14309/ajg.0000000000001146