Rurality and screening colonoscopy participation in patients with Lynch syndrome.

Abstract

10620 Background: Lynch Syndrome (LS) is a hereditary condition that increases risk for colorectal and other primary cancers. LS arises from pathogenic variants (PVs) in MLH1 , MSH2 , MSH6 , and PMS2 . Gene-specific prevention and surveillance strategies exist, and screening colonoscopy reduces overall mortality. Several barriers to screening colonoscopy are known, however the impact of rurality is not well characterized. Methods: We enumerated a cohort of LS patients residing in Vermont or upstate New York who were seen by the Cancer Genetics Program at the University of Vermont, and for whom regular screening colonoscopies were recommended based on current PV- and age-based NCCN guidelines. We reviewed electronic medical records and abstracted patient characteristics and colonoscopy procedures performed between 2021-2024, capturing most recent practices while avoiding the impact of COVID-19 restrictions. We defined screening compliance as having >1 colonoscopy in the 3-year period, concordant with the minimum expected number of procedures over this time period for all PV groups. We assigned rurality status (metropolitan/micropolitan vs. small town/rural) based on residential ZIP code using Rural-Urban Commuting Area codes. We fit log-binomial and proportional odds regression models to estimate the impact of rurality and recency of a genetics focused clinic visits on colonoscopy adherence and on the number of colonoscopies received, adjusting for age, sex, and PVs. Results: We enrolled 201 LS patients for whom annual, bi- or triennial colonoscopies were recommended. Median age at baseline was 60 years (range: 28-98), 131 (65%) were female, and 58 (29%) resided in a small town/rural setting. Compared with metropolitan/micropolitan, small town/rural residence was associated with a lower probability of having ≥1 screening colonoscopy in the 3-year follow-up period (43% vs. 64%; RR=0.67, 95% CI: 0.49, 0.92). This association did not change substantially upon adjustment for age, sex, and pathogenic variants. Small town/rural residence was also associated with undergoing fewer colonoscopies in the 3-year period (cumulative OR=0.46, 95% CI: 0.25, 0.84). Furthermore, recency of Cancer Genetics Program clinic visit was associated with a higher probability of receiving at least one colonoscopy, independent of rurality ( e.g. , RR for last visit ≤3 years ago, compared with last visit >10 years ago = 1.8, 95% CI: 1.1, 2.8). Conclusions: In a cohort of patients with LS, residing in a rural area was associated with a reduced probability of compliance with screening colonoscopy. Resources should be invested in studies aimed at understanding and ameliorating the mechanisms underlying this association. Shorter time since last clinic visit in the genetics program was associated with a higher likelihood of having a screening colonoscopy, suggesting the importance of genetics longitudinal follow-up for hereditary cancer patients.