The New England Journal of Medicine researchers examined the effectiveness of colonoscopy for colorectal cancer screening. Below, the American Cancer Society responds to that NEJM study:

Dr. Karen Knudsen, Chief Executive Officer at the American Cancer Society: “Preventive cancer screenings are the best and most trusted way to save lives. That’s why the American Cancer Society recommends colorectal cancer screening, including colonoscopy, for adults beginning at age 45. There’s no reason to change that direction. Recommended cancer screenings should be a routine part of good health.”

Dr. William Dahut, Chief Scientific Officer at the American Cancer Society: “It’s hard to know the value of a screening test when the majority of people in the study didn’t get it done. However, study patients who did undergo a colonoscopy had a 31 percent decrease in the risk of colorectal cancer as compared to those who were not screened. This result points to the value of continued screening.”

A few points are worth emphasizing:

  • Almost 60% of the people randomized to an invitation for a colonoscopy failed to have a colonoscopy. This was a one-time colonoscopy without clear data on follow-up. Colorectal cancer generally develops over a long period, and in people with polyps, follow-up is needed to treat additional polyps.

  • In this study, patients were screened from 2009 to 2014 (so many less than 10 years ago). The time from polyps to cancer to mortality is almost always greater than this-so a much longer follow-up is needed. In other diseases, such as prostate cancer, screening data looks much better over time.

  • Screening in this study started at age 55, while U.S. guidelines are at 45 years of age. This can’t even be considered for people under 55 years old (or over 65). Intervention in younger patients could potentially have a greater impact on meaningful outcomes. For more information on colorectal cancer screening tests click here. For the American Cancer Society’s cancer screening guidelines by age click here.

This article was originally published October 10, 2022, by the American Cancer Society. It is republished with permission.