Sessile Serrated Lesion Detection Rate and Colorectal Cancer Risk and Mortality

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.

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

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.

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.

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.

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.

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.