Sessile Serrated Lesion Detection Rate and Colorectal Cancer Risk and Mortality.

[IMPORTANCE] Although the adenoma detection rate is a key colonoscopy quality metric, benchmarks for serrated polyp removal, specifically the sessile serrated lesion detection rate (SSLDR), are currently lacking.

[OBJECTIVE] To evaluate the physician SSLDR and the risk of postcolonoscopy colorectal cancer (PCCRC) and related mortality.

[DESIGN, SETTING, AND PARTICIPANTS] This retrospective cohort study was conducted between January 1, 2000, and December 31, 2021, within a large integrated health care system in Northern California and included colonoscopies performed for patients aged 18 years or older, without a diagnosis of colorectal cancer within 6 months of colonoscopy, history of colorectal cancer, or history of inflammatory bowel disease by 50 gastroenterologists. Statistical analysis was performed from January 1, 2000, to December 31, 2021.

[EXPOSURE] The primary exposure was the SSLDR, defined as the proportion of screening colonoscopies with at least 1 histologically confirmed sessile serrated adenoma or traditional serrated adenoma, categorized into quartiles.

[MAIN OUTCOMES AND MEASURES] The primary outcome was PCCRC diagnosed more than 6 months after negative colonoscopy results. Secondary outcomes included proximal or distal PCCRC, advanced stage colorectal cancer, all-cause mortality, and colorectal cancer-related mortality. Outcomes were ascertained through linked state and institutional cancer registries and vital records.

[RESULTS] Among 328 416 colonoscopies performed for 226 695 unique patients (mean [SD] age, 58.6 [10.7] years; 51.7% women), 562 PCCRC cases were identified over 2 038 816 person-years of follow-up. The absolute PCCRC incidence rate decreased with higher SSLDR quartiles, from 3.9 cases per 10 000 person-years in the lowest quartile to 2.4 cases per 10 000 person-years in the highest quartile. Compared with patients in the lowest SSLDR quartile, those in the highest SSLDR quartile had a significantly lower risk of PCCRC (multivariate hazard ratio, 0.69; 95% CI, 0.50-0.94; P = .01 for trend), primarily associated with lower risk of proximal PCCRC. A higher SSLDR was associated with lower all-cause mortality (second quartile, 57.7 deaths per 10 000 person-years; third quartile, 58.0 deaths per 10 000 person-years) and colorectal cancer-related mortality (second quartile, 0.2 deaths per 10 000 person-years; third quartile, 0.2 deaths per 10 000 person-years) in the second and third SSLDR quartiles, but the association was not significant in the highest quartile compared with the lowest quartile.

[CONCLUSIONS AND RELEVANCE] In this large community-based cohort study, a higher physician SSLDR was associated with a significantly lower risk of PCCRC in a dose-dependent manner. These findings support using the SSLDR as a crucial quality metric for colonoscopy.