Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults: A Cross-sectional Study.

BACKGROUND: Several methods are recommended equally strongly for colorectal cancer screening in average-risk persons. Risk stratification would enable tailoring of screening within this group, with less invasive tests (sigmoidoscopy or occult blood tests) for lower-risk persons and colonoscopy for higher-risk persons. OBJECTIVE: To create a risk index for advanced neoplasia (colorectal cancer and adenomas or serrated polyps ≥1.0 cm, villous histology, or high-grade dysplasia) anywhere in the colorectum, using the most common risk factors for colorectal neoplasia. DESIGN: Cross-sectional study. SETTING: Multiple endoscopy units, primarily in the Midwest. PATIENTS: Persons aged 50 to 80 years undergoing initial screening colonoscopy (December 2004 to September 2011). MEASUREMENTS: Derivation and validation of a risk index based on points from regression coefficients for age, sex, waist circumference, cigarette smoking, and family history of colorectal cancer. RESULTS: Among 2993 persons in the derivation set, prevalence of advanced neoplasia was 9.4%. Risks for advanced neoplasia in persons at very low, low, intermediate, and high risk were 1.92% (95% CI, 0.63% to 4.43%), 4.88% (CI, 3.79% to 6.18%), 9.93% (CI, 8.09% to 12.0%), and 24.9% (CI, 21.1% to 29.1%), respectively (P < 0.001). Sigmoidoscopy to the descending colon in the low-risk groups would have detected 51 of 70 (73% [CI, 61% to 83%]) advanced neoplasms. Among 1467 persons in the validation set, corresponding risks for advanced neoplasia were 1.65% (CI, 0.20% to 5.84%), 3.31% (CI, 2.08% to 4.97%), 10.9% (CI, 8.26% to 14.1%), and 22.3% (CI, 16.9% to 28.5%), respectively (P < 0.001). Sigmoidoscopy would have detected 21 of 24 (87.5% [CI, 68% to 97%]) advanced neoplasms. LIMITATIONS: Split-sample validation; results apply to first-time screening. CONCLUSION: This index stratifies risk for advanced neoplasia among average-risk persons by identifying lower-risk groups for which noncolonoscopy strategies may be effective and efficient and a higher-risk group for which colonoscopy may be preferred. PRIMARY FUNDING SOURCE: National Cancer Institute, Walther Cancer Institute, Indiana University Simon Cancer Center, and Indiana Clinical and Translational Sciences Institute.

A risk index for advanced neoplasia on the second surveillance colonoscopy in patients with previous adenomatous polyps.

BACKGROUND: Predicting the risk of advanced colorectal neoplasia on the second surveillance colonoscopy could help tailor surveillance. OBJECTIVE: To derive and validate a risk index for advanced neoplasia on the second surveillance colonoscopy. DESIGN: Retrospective cohort. SETTING: Single-specialty practice; Veterans Affairs Medical Center. PATIENTS: A total of 965 patients with baseline adenomatous polyps, 2 surveillance colonoscopies, and no reported family history of colorectal cancer; validation cohort of 372. INTERVENTIONS: Multivariable logistic regression including demographics and previous colonoscopy results; derivation and validation of a risk index. MAIN OUTCOME MEASUREMENTS: Advanced adenoma (≥1 cm in size, villous histology, or high-grade dysplasia) on the second surveillance colonoscopy. RESULTS: Mean age was 57.8 ± 9.8 years, 62% were men, and 36% had an advanced adenoma on the index colonoscopy. Associated with advanced adenoma on the second surveillance colonoscopy were age at index colonoscopy (scored 0 for younger than 55 years of age, 1 for 55-59 years of age, 2 for 60-64 years of age, and 3 for older than 65 years of age) and previous findings (non-neoplastic, nonadvanced, advanced [scored 0, 1, and 2, respectively]) on index colonoscopy and the first surveillance colonoscopy, with scores ranging from 1 to 7. Risks of advanced adenoma on the second surveillance colonoscopy with scores of 5 or less and more than 5 were 4.8% (95% confidence interval, 3.5%-6.4%) and 14.9% (95% confidence interval, 7.4%-25.7%), respectively, comprising 93% and 7%, respectively, of the cohort. Corresponding results in the validation cohort were 5.6% and 19.2%, respectively, comprising 86.1% and 13.9%, respectively, of the cohort. LIMITATIONS: Retrospective study with potential for selection bias. CONCLUSION: This index stratifies the risk of advanced adenoma on the second surveillance colonoscopy. If validated independently, it may be useful for tailoring surveillance.

Yield of the second surveillance colonoscopy based on the results of the index and first surveillance colonoscopies.

BACKGROUND AND STUDY AIMS: The risk of advanced colorectal neoplasia (ACN) after the first surveillance colonoscopy is not well quantified. The aim of the current study was to quantify the risk of ACN on the second surveillance colonoscopy based on previous colonoscopic findings. PATIENTS AND METHODS: This was a single-site study of patients with index adenomas who underwent two surveillance colonoscopies. ACN was defined as advanced adenoma (≥ 1 cm, villous histology, or high-grade dysplasia) or as "high-risk" findings (advanced adenoma or ≥ 3 non-advanced adenoma [NAA]). RESULTS: Among 509 patients with low-risk index findings, 61 (12.0 %; 95 % confidence interval [CI], 9.3 % - 15.1 %) had high-risk findings on the first surveillance colonoscopy, 11 of whom (18.0 %; 95 %CI 9.4 % - 30.0 %) had high-risk findings on second surveillance colonoscopy compared with 39 (8.7 %; 95 %CI 6.3 % - 11.7 %) of the remaining 448 patients who had normal or low-risk findings on the first surveillance colonoscopy (relative risk [RR] = 2.07; 95 %CI 1.12 - 3.83). Among 456 patients with high-risk index findings, 91 (20.0 %; 95 %CI 16.3 % - 23.9 %) had high-risk findings on the first surveillance colonoscopy, 20 of whom (22.0 %; 95 %CI 14.0 % - 31.9 %) had high-risk findings on second surveillance colonoscopy compared with 40 (11.0 %; 95 %CI 8.0 % - 146 %) of the remaining 365 patients who had normal or low-risk findings on first surveillance colonoscopy (RR = 2.01; 95 %CI 1.04 - 3.32). Results were similar when only advanced adenomas were considered. CONCLUSIONS: Patients with high-risk findings on index and first surveillance colonoscopies require close surveillance. Those with low-risk findings on index colonoscopy and normal/non-advanced findings on the first surveillance colonoscopy have low subsequent risk of ACN. These and previous data may be useful for generating recommendations for the timing of the second surveillance colonoscopy.

Five-year risk of colorectal neoplasia after negative screening colonoscopy.

BACKGROUND: The appropriate interval for endoscopic rescreening after a negative colonoscopic examination is uncertain. METHODS: We identified persons with no adenomas on baseline screening colonoscopy who returned at 5 years for follow-up colonoscopy. Findings were categorized according to the most advanced lesion present: no polyp, a hyperplastic polyp, a tubular adenoma less than 1 cm in diameter, an advanced adenoma (a tubular adenoma > or = 1 cm in diameter or a polyp with villous histologic features or high-grade dysplasia), or a cancer. RESULTS: Baseline screening colonoscopy had identified 2436 persons with no adenomas; 1256 of them (51.6%) were rescreened a mean (+/-SD) of 5.34+/-1.34 years later. The mean age of this group at baseline was 56.7 years; 56.7% of its members were men. No cancers were found on rescreening (95% confidence interval [CI] for the detection rate, 0 to 0.24%). One or more adenomas were found in 201 persons (16.0%). A total of 19 advanced adenomas, of which 10 (52.6%) were distal to the splenic flexure, were found in 16 persons (1.3%). The risk of an advanced adenoma did not differ significantly between persons with no polyps at baseline and those with hyperplastic polyps at baseline (1.1% [12 of 1057] and 2.0% [4 of 199], respectively; P=0.30). Men were more likely than women to have any adenoma (tubular less than 1 cm in diameter or advanced) (relative risk, 1.88; 95% CI, 1.42 to 2.51) and to have an advanced adenoma (relative risk, 3.31; 95% CI, 1.02 to 10.8). CONCLUSIONS: Among persons with no colorectal neoplasia on initial screening colonoscopy, the 5-year risk of colorectal cancer is extremely low. The risk of advanced adenoma is also low, although it is higher among men than among women. Our findings support a rescreening interval of 5 years or longer after a normal colonoscopic examination.

Variation in polyp detection rates at screening colonoscopy.

BACKGROUND: Variation in polyp detection among endoscopists has been used to justify the need for establishing quality standards for colonoscopy performance. OBJECTIVE: To measure variation in polyp detection rates (PDRs) among endoscopists who perform screening colonoscopy and to identify associated factors. DESIGN: Cross-sectional analysis of summary-level data. SETTING: Endoscopy practices in central Indiana. SUBJECTS: Twenty-five endoscopists and their patients. MAIN OUTCOME MEASUREMENTS: Mean procedure time (MPT); proportions of patients with any polyp, any adenoma, any polyp > or =1.0 cm, and multiple adenomas; and variation in PDRs and identification of outliers. Multiple linear regression analysis identified factors that accounted for the variation in PDRs. RESULTS: A total of 2664 screening colonoscopies (1108 women and 1556 men) were performed. The mean patient age was 59 years; the mean proportion of women was 42%; the MPT was 17.1 minutes. Adenoma detection rates ranged from 7% to 44% (P < .001) and from 0% to 13% for large polyps, which was not statistically significant (P = .07). For all polyp categories, only 1 to 3 high outlier endoscopists (ie, higher than mean PDRs) were identified. Models that included the number of procedures, mean age, percentage of women, and MPT accounted for 36% to 56% of the variation in PDRs. In all models, only MPT was significantly associated with PDRs. LIMITATIONS: Whether each endoscopist's cohort was at comparable risk for colorectal neoplasia was uncertain. In comparison with individual-level data, analysis of summary-level data is limited. CONCLUSIONS: PDRs vary widely among endoscopists, although only a few (high) outliers were identified. Variation in PDRs was associated only with MPT. Further research is needed to determine the clinical importance of and reasons for this variation.

Tailoring colorectal cancer screening by considering risk of advanced proximal neoplasia.

BACKGROUND: Quantifying the risk of advanced proximal colorectal neoplasia might allow tailoring of colorectal cancer screening, with colonoscopy for those at high risk and less invasive screening for very low-risk persons. METHODS: We analyzed findings from 10,124 consecutive adults aged≥50 years who underwent screening colonoscopy to the cecum. We quantified the risk of advanced neoplasia (tubular adenoma≥1 cm, a polyp with villous histology or high-grade dysplasia, or adenocarcinoma) both proximally (cecum to splenic flexure) and distally (descending colon to anus). The prevalence of advanced proximal neoplasia was quantified by age, gender, and distal findings. RESULTS: The mean (standard deviation) age was 57.5 (6.0) years; 44% were women; 7835 (77%) had no neoplasia, and 1856 (18%) had 1 or more nonadvanced adenomas. Overall, 433 subjects (4.3%) had advanced neoplasia (267 distally, 196 proximally, 30 both), 33 (0.33%) of which were adenocarcinoma (18 distal, 15 proximal). The risk of advanced proximal neoplasia increased with age decade (1.13%, 2.00%, and 5.26%, respectively; P=.001) and was higher in men (relative risk [RR], 1.91; confidence interval [CI], 1.32-2.77). In women aged less than 70 years, the risk was 1.1% overall (vs 2.2% in men; RR, 1.98; CI, 1.42-2.76) and 0.86% in those with no distal neoplasia (vs 1.54% in men; RR, 1.81; CI, 1.20-2.74). CONCLUSIONS: Risk of advanced proximal neoplasia is a function of age and gender. Women aged less than 60 to 70 years have a very low risk, particularly those with no distal adenoma. Sigmoidoscopy with or without occult blood testing may be sufficient and even preferable for screening these subgroups.

Risk factors for advanced sporadic colorectal neoplasia in persons younger than age 50.

BACKGROUND: Colorectal cancer (CRC) screening is recommended for average-risk adults beginning at age 50. However, 7% of CRC occurs in persons younger than age 50, a group for which risk factors are not well defined. We sought to determine whether a retrospective case-control study could identify risk factors for sporadic CRC and advanced adenomatous polyps (together known as sporadic colorectal neoplasia [CRN]). METHODS: Using the cancer registry, medical records, and endoscopy and pathology reports from six local hospitals, we identified potentially eligible persons with CRN (cases) or controls who had no neoplasia on colonoscopy between January 1, 2000 and December 31, 2002. Consenting subjects completed a survey encompassing medical and family history, physical measures, lifestyle habits, and diet. RESULTS: Surveys were completed by 20 (15%) of 130 potentially eligible cases and by 54 (13%) of 408 potentially eligible controls. The following factors differed between cases and controls: living with a spouse/significant other (55% vs. 80%; P=0.034); prior pelvic irradiation (20% vs. 2%; P=0.019); having a first-degree relative with CRC (25% vs. 7%; P=0.05); having had a prior sigmoidoscopy, colonoscopy, or barium enema (15% vs. 41%; P=0.038); and lightest weight since age 21 (155lbs vs. 135lbs; gender-adjusted P=0.049). CONCLUSIONS: The low recruitment rate of this retrospective case-control study precludes its use for a larger, more definitive study. Several potential risk factors for advanced sporadic CRN were identified. It remains to be determined whether these factors represent an artifact of selection bias or true risk factors that may be used to stratify risk and target screening in persons under age 50.