Biennial Surveillance Is the Right Interval in Lynch
Douglas K. Rex, MD, FASGE reviewing Peterese EFP, et al. Clin Gastroenterol Hepatol 2019 Oct 17.
Universal screening of colorectal cancers (CRCs) for Lynch syndrome by microsatellite instability testing or immunohistochemistry (IHC) for mismatch repair gene products is commonly recommended. Around the world, recommended intervals for Lynch colonoscopy surveillance range from 1 to 3 years.
To estimate the cost-effectiveness of these practices, a patient flow diagram was used to determine costs and yield of IHC testing, followed by genetic testing of appropriate patients with positive tumor tests and then genetic testing of their first-degree relatives (FDRs), when Lynch mutations are found. The MISCAN-colon model was used to test the cost-effectiveness of every 1- versus 2- versus 3-year colonoscopy.
Testing 1000 CRC cases occurring at age <70 years led to the identification of 20 Lynch patients at a cost of $278,558. Genetic testing of 119 family members resulted in 29 Lynch carriers at a cost of $31,716. Without screening, MISCAN predicted 359 CRC cases and 165 CRC deaths in 1000 Lynch-positive FDRs of CRC patients age <70 years.
Lynch syndrome testing was highly cost-effective, depending on the colonoscopy interval. There were 741 life-years gained per 1000 Lynch syndrome-positive FDRs with biennial surveillance, with an incremental cost-effectiveness ratio (ICER) of $8,785 per life-year gained, compared to usual care. Triennial surveillance was less effective and actually more expensive than biennial surveillance because of the high cost of cancer care, and annual surveillance added little to effectiveness at a high cost, with an unfavorable ICER of $218,647 per life-year gained, compared to biennial colonoscopy.
COMMENT
This is useful information, particularly in the U.S., where we often hear that Lynch patients should have annual colonoscopies. While a subset of Lynch patients have multiple polyps and advanced lesions and need annual watching, at least until their colonoscopies turn negative, others have repeated negative colonoscopies, and these data support biennial colonoscopy as the best approach.
Note to readers: At the time we reviewed this paper, its publisher noted that it was not in final form and that subsequent changes might be made.
Douglas K. Rex, MD, FASGE
CITATION(S)
Peterese EFP, Naber SK, Daly C, et al. Cost-effectiveness of active identification and subsequent colonoscopy surveillance of Lynch syndrome cases. Clin Gastroenterol Hepatol 2019 Oct 17. (Epub ahead of print) (https://doi.org/10.1016/j.cgh.2019.10.021)
