Colonoscopy vs Sigmoidoscopy: A Comparative Effectiveness Study

A recent comparative effectiveness study published in the Journal of American Medical Association highlights the long-term benefits of colonoscopy versus sigmoidoscopy in reducing colorectal cancer (CRC) incidence and mortality. The study was conducted by pooling data from four randomized sigmoidoscopy screening trials in Norway, Italy, the US, and UK that offers valuable insights into the effectiveness of different screening methods.

The study analyzed data from over 350,000 participants who were aged 55 to 64 years and were randomly assigned to either sigmoidoscopy screening or usual care between 1993 and 2001. The researchers evaluated CRC incidence and mortality over a 15 to 17-year follow-up period to estimate the additional benefit of colonoscopy when compared to sigmoidoscopy.

The findings revealed that colonoscopy screening was associated with a significant reduction in CRC cases and deaths. When compared to the usual care, colonoscopy prevented an estimated 50 CRC cases per 100,000 person-years, translating to a 30% reduction in the incidence and 15 CRC deaths per 100,000 person-years that corresponds to a 32% reduction in mortality.

This study highlighted that the additional benefit of colonoscopy over sigmoidoscopy included 12 fewer CRC cases and 4 fewer CRC deaths per 100,000 person-years. While this represented a significant improvement, it was observed to be less substantial than the impact achieved by introducing sigmoidoscopy screening in areas without prior screening programs. This study emphasized the significance of these findings in informing CRC screening strategies and the importance of considering the long-term effectiveness of different screening modalities in CRC prevention.

Reference

Juul, F. E., Cross, A. J., Schoen, R. E., Senore, C., Pinsky, P. F., Miller, E. A., Segnan, N., Wooldrage, K., Wieszczy-Szczepanik, P., Armaroli, P., Garborg, K. K., Adami, H.-O., Hoff, G., Kalager, M., Bretthauer, M., Holme, Ø., & Løberg, M. (2024). Effectiveness of Colonoscopy Screening vs Sigmoidoscopy Screening in Colorectal Cancer. In JAMA Network Open (Vol. 7, Issue 2, p. e240007). American Medical Association (AMA). https://doi.org/10.1001/jamanetworkopen.2024.0007