Tailoring Surveillance Colonoscopy in Patients With Advanced Adenomas

Abstract

Background & aims: Patients with advanced colorectal adenomas (AAs) are directed to undergo intensive surveillance. However, the benefit derived from surveillance may be outweighed by the risk of death from non-colorectal cancer (CRC) causes, leading to uncertainty on how best to individualize follow-up. The aim of this study was to derive a risk prediction model and risk index that estimate and stratify the risk for non-CRC cancer mortality (NCM) subsequent to diagnosis and removal of AA.

Methods: We conducted a retrospective cohort study of veterans ≥40 years old who had colonoscopy for diagnostic or screening indications at 13 Veterans Affairs Medical Centers between 2002 and 2009 and had 1 or more AAs. The primary outcome was NCM using a fixed follow-up time period of 5 years. Logistic regression using the lasso technique was used to identify factors independently associated with NCM, and an index based on points from regression coefficients was constructed to estimate risk of 5-year NCM.

Results: We identified 2943 veterans with AA (mean age [standard deviation] 63 [8.6] years, 98% male, 74% white), with an overall 5-year mortality of 16.7%, which was nearly all due to NCM (16.6%). Age, comorbidity burden, specific comorbid conditions, and hospitalization within the preceding year were independently associated with NCM. The risk prediction model had a goodness of fit (calibration) P value of .41 and c-statistic (discrimination) of 0.74 (95% confidence interval, 0.71-0.76). On the basis of comparable 5-year risks of NCM, the scores comprised 3 risk categories: low (score of 0-1), intermediate (score of 2-4), and high (score of ≥5), in which NCM occurred in 6.5%, 14.1%, and 33.2%, respectively.

Conclusions: We derived a risk prediction model that identifies veterans with advanced adenomas who are at high risk of NCM within 5 years, and who are thus unlikely to benefit from further surveillance.

Keywords: Colonoscopy; Colorectal Neoplasia; Surveillance.