NEJM: Adenoma detection rates may predict interval colorectal cancer

Twitter icon
Facebook icon
LinkedIn icon
e-mail icon
Google icon
The adenomatous lesion detection rate is an independent predictorof the risk of interval colorectal cancer after screening colonoscopy, according to the findings of a recent study published in the May edition of the New England Journal of Medicine.

Jaroslaw Regula, MD, of the Department of Gastroenterology at the Institute of Oncology in Warsaw, Poland, and colleagues said that despite rates of adenoma detection and cecal intubation being recommended foruse as quality indicators for screening colonoscopy, these measurementshave not been validated.

“The primaryaim of the study was to assess the association between qualityindicators for colonoscopy and the risk of interval cancer,” wrote Regula and colleagues.

Utilizing a multivariate Cox proportional-hazards regressionmodel in order to evaluate the influence of quality indicators for colonoscopyon the risk of interval cancer (colorectal adenocarcinoma that was diagnosedbetween the time of screening colonoscopy and the scheduledtime of surveillance colonoscopy), the researchers gathered data from 186endoscopists who were involved in a colonoscopy-based colorectal-cancerscreening program involving 45,026 patients. By way of the screening program's databaseand data on interval cancers from cancer registries, the authors acquired quality-indicating data for colonoscopy.

After an average follow-up period of 52.1 months, 42 interval colorectal cancers were identified. Of these cancers,35 (83.3 percent) occurred in subjects with no family history of colorectalcancer and 39 (92.9 percent) occurred in subjects in whom no adenomashad been identified at the screening examination. The authors wrote that the interval cancer could be attributed to anineffective polypectomy in one patient (2.4 percent), as the completeness of the polypectomy was undetermined.

“The endoscopist's rateof detection of adenomas was significantly associated with therisk of interval colorectal cancer… The risk was significantlyhigher among subjects who underwent colonoscopies that wereperformed by endoscopists with an adenoma detection rate ofless than 20 percent than among subjects examined by endoscopists witha detection rate of 20 percent or more, whereas the rateof cecal intubation was not significantly associated with thisrisk,” said Regula.

Citing age as another factor that was independently associatedwith the risk of interval colorectal cancer, as risk was found to be particularly high for subjects who were 60years of age or older, the authors noted that limitations to their study included the fact that there is no universally accepted definition ofinterval cancer, as well as potentially incomplete cancer registries.

“These results, obtained ina large cohort, underscore the crucial role of meticulous inspectionof the colorectal mucosa at the baseline examination and indicatethat such inspection is a very important factor in the efficacyof screening,” concluded the researchers.