Lead Time and Immortal Time Biases Impact the Calculation of Post-colonoscopy Colorectal Cancer Survival.

The World Endoscopy Organization (WEO) standardized the reporting of post-colonoscopy colorectal cancers (PCCRCs), which account for 7% to 10% of colorectal cancers (CRCs).1 PCCRCs are diagnosed 6 to 36 months after a false negative colonoscopy. Detected CRCs (dCRCs) are diagnosed ≤6 months after an index true positive colonoscopy.2 PCCRC prognosis is unclear, with outcomes reported as comparable,3 superior,4 or inferior5,6 to those of dCRC. Because WEO terminology defines cases relative to the index colonoscopy, conventional survival analyses of PCCRC are susceptible to lead time and immortal time biases. We evaluated the influence of these biases on mortality in a population-based retrospective cohort of 10,938 dCRCs (93.8%) and 717 PCCRCs (6.2%). This study was set within Kaiser Permanente Northern California (KPNC), a large integrated health system, whose members are similar in demographic and socioeconomic characteristics to the Northern California region.7.

Randomized Trial of Patient Outreach Approaches to De-implement Outdated Colonoscopy Surveillance Intervals.

BACKGROUND AND AIMS: Guidelines now recommend patients with low-risk adenomas receive colonoscopy surveillance in 7-10 years and those with the previously recommended 5-year interval be re-evaluated. We tested 3 outreach approaches for transitioning patients to the 10-year interval recommendation. METHODS: This was a 3-arm pragmatic randomized trial comparing telephone, secure messaging, and mailed letter outreach. The setting was Kaiser Permanente Northern California, a large integrated healthcare system. Participants were patients 54-70 years of age with 1-2 small (<10 mm) tubular adenomas at baseline colonoscopy, due for 5-year surveillance in 2022, without high-risk conditions, and with access to all 3 outreach modalities. Patients were randomly assigned to the outreach arm (telephone [n = 200], secure message [n = 203], and mailed letter [n = 201]) stratified by age, sex, and race/ethnicity. Outreach in each arm was performed by trained medical assistants (unblinded) communicating in English with 1 reminder attempt at 2-4 weeks. Participants could change their assigned interval to 10 years or continue their planned 5-year interval. RESULTS: Sixty-day response rates were higher for telephone (64.5%) and secure messaging outreach (51.7%) vs mailed letter (31.3%). Also, more patients adopted the 10-year surveillance interval in the telephone (37.0%) and secure messaging arms (32.0%) compared with mailed letter (18.9%) and rate differences were significant for telephone (18.1%; 97.5% confidence interval: 8.3%-27.9%) and secure message outreach (13.1%; 97.5% confidence interval: 3.5%-22.7%) vs mailed letter outreach. CONCLUSIONS: Telephone and secure messaging were more effective than mailed letter outreach for de-implementing outdated colonoscopy surveillance recommendations among individuals with a history of low-risk adenomas in an integrated healthcare setting. (ClinicalTrials.gov, Number: NCT05389397).

Predicting Risk of Colorectal Cancer After Adenoma Removal in a Large Community-Based Setting.

INTRODUCTION: Colonoscopy surveillance guidelines categorize individuals as high or low risk for future colorectal cancer (CRC) based primarily on their prior polyp characteristics, but this approach is imprecise, and consideration of other risk factors may improve postpolypectomy risk stratification. METHODS: Among patients who underwent a baseline colonoscopy with removal of a conventional adenoma in 2004-2016, we compared the performance for postpolypectomy CRC risk prediction (through 2020) of a comprehensive model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and prior polyp findings (i.e., adenoma with advanced histology, polyp size ≥10 mm, and sessile serrated adenoma or traditional serrated adenoma) with a polyp model featuring only polyp findings. Models were developed using Cox regression. Performance was assessed using area under the receiver operating characteristic curve (AUC) and calibration by the Hosmer-Lemeshow goodness-of-fit test. RESULTS: Among 95,001 patients randomly divided 70:30 into model development (n = 66,500) and internal validation cohorts (n = 28,501), 495 CRC were subsequently diagnosed; 354 in the development cohort and 141 in the validation cohort. Models demonstrated adequate calibration, and the comprehensive model demonstrated superior predictive performance to the polyp model in the development cohort (AUC 0.71, 95% confidence interval [CI] 0.68-0.74 vs AUC 0.61, 95% CI 0.58-0.64, respectively) and validation cohort (AUC 0.70, 95% CI 0.65-0.75 vs AUC 0.62, 95% CI 0.57-0.67, respectively). DISCUSSION: A comprehensive CRC risk prediction model featuring patient age, diabetes diagnosis, and baseline colonoscopy indication and polyp findings was more accurate at predicting postpolypectomy CRC diagnosis than a model based on polyp findings alone.

Patterns of Care Following a Positive Fecal Blood Test for Colorectal Cancer: A Mixed Methods Study.

BACKGROUND/OBJECTIVE: Multilevel barriers to colonoscopy after a positive fecal blood test for colorectal cancer (CRC) are well-documented. A less-explored barrier to appropriate follow-up is repeat fecal testing after a positive test. We investigated this phenomenon using mixed methods. DESIGN: This sequential mixed methods study included quantitative data from a large cohort of patients 50-89 years from four healthcare systems with a positive fecal test 2010-2018 and qualitative data from interviews with physicians and patients. MAIN MEASURES: Logistic regression was used to evaluate whether repeat testing was associated with failure to complete subsequent colonoscopy and to identify factors associated with repeat testing. Interviews were coded and analyzed to explore reasons for repeat testing. KEY RESULTS: A total of 316,443 patients had a positive fecal test. Within 1 year, 76.3% received a colonoscopy without repeat fecal testing, 3% repeated testing and then received a colonoscopy, 4.4% repeated testing without colonoscopy, and 16.3% did nothing. Among repeat testers (7.4% of total cohort, N = 23,312), 59% did not receive a colonoscopy within 1 year. In adjusted models, those with an initial positive test followed by a negative second test were significantly less likely to receive colonoscopy than those with two successive positive tests (OR 0.37, 95% CI 0.35-0.40). Older age (65-75 vs. 50-64 years: OR 1.37, 95% CI 1.33-1.41) and higher comorbidity score (≥ 4 vs. 0: OR 1.75, 95% CI 1.67-1.83) were significantly associated with repeat testing compared to those who received colonoscopy without repeat tests. Qualitative interview data revealed reasons underlying repeat testing, including colonoscopy avoidance, bargaining, and disbelief of positive results. CONCLUSIONS: Among patients in this cohort, 7.4% repeated fecal testing after an initial positive test. Of those, over half did not go on to receive a colonoscopy within 1 year. Efforts to improve CRC screening must address repeat fecal testing after a positive test as a barrier to completing colonoscopy.

Biopsy of Non-tumor Sites After Biopsy of a Colorectal Cancer is not Associated With Metachronous Cancers: A Case-control Study.

BACKGROUND & AIMS: Recent research has demonstrated biologic plausibility for iatrogenic tumor seeding via colonoscopy as a cause of metachronous colorectal cancers (CRC). This study evaluated the association between biopsy of non-tumor sites after CRC biopsy and risk of metachronous CRC in a large community-based health care organization. METHODS: This was a retrospective case-control study of adults with an initial CRC diagnosed by colonoscopy between January 2006 and June 2018 who underwent curative resection. Cases developed a second primary (metachronous) CRC diagnosed 6 months to 4 years after the initial CRC, and were matched by age, sex, diagnosis of inflammatory bowel disease, race, and ethnicity with up to 5 controls without a second CRC diagnosis. The exposure was biopsy in the colonic segment of the metachronous CRC (or corresponding segment in controls) after tumor biopsy, ascertained with blinding to case status. Associations were evaluated using conditional logistic regression and adjusted for potential cofounders. RESULTS: Among 14,119 patients diagnosed with an initial CRC during colonoscopy, 107 received a second CRC diagnosis. After exclusions for recurrent or synchronous CRC, 45 cases and 212 controls were included. There was no significant association between biopsy of non-tumor sites after initial CRC biopsy and risk of metachronous CRC in the segment of the additional biopsy site (adjusted odds ratio, 2.29; 95% confidence interval, 0.77-6.81). CONCLUSIONS: Metachronous cancers are not significantly associated with biopsy of non-tumor sites after biopsy of the primary cancer. Although the sample size does not allow definite exclusion of any association, these findings do not support iatrogenic tumor seeding as a common risk factor for metachronous CRC.

Impact of the COVID-19 Pandemic on Fecal Immunochemical Testing, Colonoscopy Services, and Colorectal Neoplasia Detection in a Large United States Community-based Population.

BACKGROUND & AIMS: The COVID-19 pandemic has affected clinical services globally, including colorectal cancer (CRC) screening and diagnostic testing. We investigated the pandemic's impact on fecal immunochemical test (FIT) screening, colonoscopy utilization, and colorectal neoplasia detection across 21 medical centers in a large integrated health care organization. METHODS: We performed a retrospective cohort study in Kaiser Permanente Northern California patients ages 18 to 89 years in 2019 and 2020 and measured changes in the numbers of mailed, completed, and positive FITs; colonoscopies; and cases of colorectal neoplasia detected by colonoscopy in 2020 vs 2019. RESULTS: FIT kit mailings ceased in mid-March through April 2020 but then rebounded and there was an 8.7% increase in kits mailed compared with 2019. With the later mailing of FIT kits, there were 9.0% fewer FITs completed and 10.1% fewer positive tests in 2020 vs 2019. Colonoscopy volumes declined 79.4% in April 2020 compared with April 2019 but recovered to near pre-pandemic volumes in September through December, resulting in a 26.9% decline in total colonoscopies performed in 2020. The number of patients diagnosed by colonoscopy with CRC and advanced adenoma declined by 8.7% and 26.9%, respectively, in 2020 vs 2019. CONCLUSIONS: The pandemic led to fewer FIT screenings and colonoscopies in 2020 vs 2019; however, after the lifting of shelter-in-place orders, FIT screenings exceeded, and colonoscopy volumes nearly reached numbers from those same months in 2019. Overall, there was an 8.7% reduction in CRC cases diagnosed by colonoscopy in 2020. These data may help inform the development of strategies for CRC screening and diagnostic testing during future national emergencies.

Impact of a scalable training program on the quality of colonoscopy performance and risk of postcolonoscopy colorectal cancer.

BACKGROUND AND AIMS: Endoscopist adenoma detection rates (ADRs) vary widely and are associated with patients' risk of postcolonoscopy colorectal cancers (PCCRCs). However, few scalable physician-directed interventions demonstrably both improve ADR and reduce PCCRC risk. METHODS: Among patients undergoing colonoscopy, we evaluated the influence of a scalable online training on individual-level ADRs and PCCRC risk. The intervention was a 30-minute, interactive, online training, developed using behavior change theory, to address factors that potentially impede detection of adenomas. Analyses included interrupted time series analyses for pretraining versus posttraining individual-physician ADR changes (adjusted for temporal trends) and Cox regression for associations between ADR changes and patients' PCCRC risk. RESULTS: Across 21 endoscopy centers and all 86 eligible endoscopists, ADRs increased immediately by an absolute 3.13% (95% confidence interval [CI], 1.31-4.94) in the 3-month quarter after training compared with .58% per quarter (95% CI, .40-.77) and 0.33% per quarter (95% CI, .16-.49) in the 3-year pretraining and posttraining periods, respectively. Posttraining ADR increases were higher among endoscopists with pretraining ADRs below the median. Among 146,786 posttraining colonoscopies (all indications), each 1% absolute increase in screening ADR posttraining was associated with a 4% decrease in their patients' PCCRC risk (hazard ratio, .96; 95% CI, .93-.99). An ADR increase of ≥10% versus <1% was associated with a 55% reduced risk of PCCRC (hazard ratio, .45; 95% CI, .24-.82). CONCLUSIONS: A scalable, online behavior change training intervention focused on modifiable factors was associated with significant and sustained improvements in ADR, particularly among endoscopists with lower ADRs. These ADR changes were associated with substantial reductions in their patients' risk of PCCRC.

Program Components and Results From an Organized Colorectal Cancer Screening Program Using Annual Fecal Immunochemical Testing.

BACKGROUND AND AIMS: Programmatic colorectal cancer (CRC) screening increases uptake, but the design and resources utilized for such models are not well known. We characterized program components and participation at each step in a large program that used mailed fecal immunochemical testing (FIT) with opportunistic colonoscopy. METHODS: Mixed-methods with site visits and retrospective cohort analysis of 51-75-year-old adults during 2017 in the Kaiser Permanente Northern California integrated health system. RESULTS: Among 1,023,415 screening-eligible individuals, 405,963 (40%) were up to date with screening at baseline, and 507,401 of the 617,452 not up-to-date were mailed a FIT kit. Of the entire cohort (n = 1,023,415), 206,481 (20%) completed FIT within 28 days of mailing, another 61,644 (6%) after a robocall at week 4, and 40,438 others (4%) after a mailed reminder letter at week 6. There were over 800,000 medical record screening alerts generated and about 295,000 FIT kits distributed during patient office visits. About 100,000 FIT kits were ordered during direct-to-patient calls by medical assistants and 111,377 people (11%) completed FIT outside of the automated outreach period. Another 13,560 (1.3%) completed a colonoscopy, sigmoidoscopy, or fecal occult blood test unrelated to FIT. Cumulatively, 839,463 (82%) of those eligible were up to date with screening at the end of the year and 12,091 of 14,450 patients (83.7%) with positive FIT had diagnostic colonoscopy. CONCLUSIONS: The >82% screening participation achieved in this program resulted from a combination of prior endoscopy (40%), large initial response to mailed FIT kits (20%), followed by smaller responses to automated reminders (10%) and personal contact (12%).

Association of Physician Adenoma Detection Rates With Postcolonoscopy Colorectal Cancer.

Importance: Although colonoscopy is frequently performed in the United States, there is limited evidence to support threshold values for physician adenoma detection rate as a quality metric. Objective: To evaluate the association between physician adenoma detection rate values and risks of postcolonoscopy colorectal cancer and related deaths. Design, Setting, and Participants: Retrospective cohort study in 3 large integrated health care systems (Kaiser Permanente Northern California, Kaiser Permanente Southern California, and Kaiser Permanente Washington) with 43 endoscopy centers, 383 eligible physicians, and 735 396 patients aged 50 to 75 years who received a colonoscopy that did not detect cancer (negative colonoscopy) between January 2011 and June 2017, with patient follow-up through December 2017. Exposures: The adenoma detection rate of each patient's physician based on screening examinations in the calendar year prior to the patient's negative colonoscopy. Adenoma detection rate was defined as a continuous variable in statistical analyses and was also dichotomized as at or above vs below the median for descriptive analyses. Main Outcomes and Measures: The primary outcome (postcolonoscopy colorectal cancer) was tumor registry-verified colorectal adenocarcinoma diagnosed at least 6 months after any negative colonoscopy (all indications). The secondary outcomes included death from postcolonoscopy colorectal cancer. Results: Among 735 396 patients who had 852 624 negative colonoscopies, 440 352 (51.6%) were performed on female patients, median patient age was 61.4 years (IQR, 55.5-67.2 years), median follow-up per patient was 3.25 years (IQR, 1.56-5.01 years), and there were 619 postcolonoscopy colorectal cancers and 36 related deaths during more than 2.4 million person-years of follow-up. The patients of physicians with higher adenoma detection rates had significantly lower risks for postcolonoscopy colorectal cancer (hazard ratio [HR], 0.97 per 1% absolute adenoma detection rate increase [95% CI, 0.96-0.98]) and death from postcolonoscopy colorectal cancer (HR, 0.95 per 1% absolute adenoma detection rate increase [95% CI, 0.92-0.99]) across a broad range of adenoma detection rate values, with no interaction by sex (P value for interaction = .18). Compared with adenoma detection rates below the median of 28.3%, detection rates at or above the median were significantly associated with a lower risk of postcolonoscopy colorectal cancer (1.79 vs 3.10 cases per 10 000 person-years; absolute difference in 7-year risk, -12.2 per 10 000 negative colonoscopies [95% CI, -10.3 to -13.4]; HR, 0.61 [95% CI, 0.52-0.73]) and related deaths (0.05 vs 0.22 cases per 10 000 person-years; absolute difference in 7-year risk, -1.2 per 10 000 negative colonoscopies [95%, CI, -0.80 to -1.69]; HR, 0.26 [95% CI, 0.11-0.65]). Conclusions and Relevance: Within 3 large community-based settings, colonoscopies by physicians with higher adenoma detection rates were significantly associated with lower risks of postcolonoscopy colorectal cancer across a broad range of adenoma detection rate values. These findings may help inform recommended targets for colonoscopy quality measures.

Early Screening of African Americans (45-50 Years Old) in a Fecal Immunochemical Test-Based Colorectal Cancer Screening Program.

BACKGROUND & AIMS: Some guidelines recommend starting colorectal cancer (CRC) screening before age 50 years for African Americans, but there are few data on screening uptake and yield in this population. METHODS: We performed a prospective study of fecal immunochemical test (FIT) screening among African American members of the Kaiser Permanente Northern California health plan. We compared data from African American members screened when they were 45-50 years old (early screening group) in 2018 with data from previously unscreened African American, white, Hispanic, and Asian/Pacific Islander health plan members who were 51-56 years old. Screening outreach was performed with mailed FIT kits. Logistic regression models, adjusted for sex, were used to evaluate differences among groups in screening uptake, colonoscopy follow-up of abnormal test results, and test yield. RESULTS: Among 10,232 African Americans in the early screening group who were mailed a FIT, screening was completed by 33.1%. Among the 4% with positive test results, 85.3% completed a follow-up colonoscopy: 57.8% had any adenoma, 33.6% had an advanced adenoma (adenoma with advanced histology or polyp ≥10 mm), and 2.6% were diagnosed with CRC. African Americans in the early screening group were modestly more likely to have completed screening than previously unscreened African Americans, whites, and Hispanics 51-56 years old. The groups did not differ significantly in positive results from the FIT (range, 3.8%-4.6%) and more than 74% received a follow-up colonoscopy after a positive test result. The test yields for any adenoma (range, 56.7%-70.7%), advanced adenoma (range, 20.0%-33.6%), and CRC (range, 0%-7.1%) were similar. CONCLUSIONS: Proportions of African Americans who participated in early (aged 45-50 years) FIT screening and test yield were comparable to those of previously unscreened African Americans, whites, Hispanics, and Asian/Pacific Islanders who were 51-56 years old.

Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population.

BACKGROUND & AIMS: The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings. METHODS: Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders. RESULTS: Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18). CONCLUSIONS: With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

Modifiable Failures in the Colorectal Cancer Screening Process and Their Association With Risk of Death.

BACKGROUND & AIMS: Colorectal cancer (CRC) deaths occur when patients do not receive screening or have inadequate follow-up of abnormal results or when the screening test fails. We have few data on the contribution of each to CRC-associated deaths or factors associated with these events. METHODS: We performed a retrospective cohort study of patients in the Kaiser Permanente Northern and Southern California systems (55-90 years old) who died of CRC from 2006 through 2012 and had ≥5 years of enrollment before diagnosis. We compared data from patients with those from a matched cohort of cancer-free patients in the same system. Receipt, results, indications, and follow-up of CRC tests in the 10-year period before diagnosis were obtained from electronic databases and chart audits. RESULTS: Of 1750 CRC deaths, 75.9% (n = 1328) occurred in patients who were not up to date in screening and 24.1% (n = 422) occurred in patients who were up to date. Failure to screen was associated with fewer visits to primary care physicians. Of 3486 cancer-free patients, 44.6% were up to date in their screening. Patients who were up to date in their screening had a lower risk of CRC death (odds ratio, 0.38; 95% confidence interval, 0.33-0.44). Failure to screen, or failure to screen at appropriate intervals, occurred in a 67.8% of patients who died of CRC vs 53.2% of cancer-free patients; failure to follow-up on abnormal results occurred in 8.1% of patients who died of CRC vs 2.2% of cancer-free patients. CRC death was associated with higher odds of failure to screen or failure to screen at appropriate intervals (odds ratio, 2.40; 95% confidence interval, 2.07-2.77) and failure to follow-up on abnormal results (odds ratio, 7.26; 95% confidence interval, 5.26-10.03). CONCLUSIONS: Being up to date on screening substantially decreases the risk of CRC death. In 2 health care systems with high rates of screening, most people who died of CRC had failures in the screening process that could be rectified, such as failure to follow-up on abnormal findings; these significantly increased the risk for CRC death.

Proton Pump Inhibitor Use and Risk of Gastric, Colorectal, Liver, and Pancreatic Cancers in a Community-Based Population.

INTRODUCTION: Proton pump inhibitors (PPIs) are commonly used for gastrointestinal disorders; given they increase the systemic levels of gastrin, a trophic hormone, there is a concern about their carcinogenicity. This study evaluated the association between PPI use and gastrointestinal cancers. METHODS: We performed a nested case-control study in a large, community-based integrated healthcare setting. Cases were adults with gastric (n = 1,233), colorectal (n = 18,595), liver (n = 2,329), or pancreatic cancers (n = 567). Each case was matched with up to 10 controls by age, sex, race/ethnicity, medical facility, and enrollment duration. The primary exposure was defined as ≥2-year cumulative PPI supply. Data were obtained from pharmacy, cancer registry, and electronic medical record databases. Associations were evaluated using conditional logistic regression and adjusted for multiple confounders. We also evaluated the cancer risks separately by PPI dose, duration of use, and dose and duration. RESULTS: PPI use of ≥2-years was not associated with the risks of gastric (odds ratio [OR]: 1.07, 95% confidence interval [CI]: 0.81-1.42), colorectal (OR: 1.05, 95% CI: 0.99-1.12), liver (OR: 1.14, 95% CI: 0.91-1.43), or pancreatic cancers (OR: 1.22, 95% CI: 0.89-1.67), compared to non-users. In exploratory analyses, elevated cancer risks were primarily restricted to those with ≥10 years of PPI use, but no consistent associations were found for increasing PPI dose and/or duration of use. DISCUSSION: PPI use of ≥2 years was not associated with increased risks of gastrointestinal cancers. The cancer risks associated with PPI use of ≥10 years requires further study.

Effects of Organized Colorectal Cancer Screening on Cancer Incidence and Mortality in a Large Community-Based Population.

BACKGROUND & AIMS: Little information is available on the effectiveness of organized colorectal cancer (CRC) screening on screening uptake, incidence, and mortality in community-based populations. METHODS: We contrasted screening rates, age-adjusted annual CRC incidence, and incidence-based mortality rates before (baseline year 2000) and after (through 2015) implementation of organized screening outreach, from 2007 through 2008 (primarily annual fecal immunochemical testing and colonoscopy), in a large community-based population. Among screening-eligible individuals 51-75 years old, we calculated annual up-to-date status for cancer screening (by fecal test, sigmoidoscopy, or colonoscopy), CRC incidence, cancer stage distributions, and incidence-based mortality. RESULTS: Initiation of organized CRC screening significantly increased the up-to-date status of screening, from 38.9% in 2000 to 82.7% in 2015 (P < .01). Higher rates of screening were associated with a 25.5% reduction in annual CRC incidence between 2000 and 2015, from 95.8 to 71.4 cases/100,000 (P < .01), and a 52.4% reduction in cancer mortality, from 30.9 to 14.7 deaths/100,000 (P < .01). Increased screening was initially associated with increased CRC incidence, due largely to greater detection of early-stage cancers, followed by decreases in cancer incidence. Advanced-stage CRC incidence rates decreased 36.2%, from 45.9 to 29.3 cases/100,000 (P < .01), and early-stage CRC incidence rates decreased 14.5%, from 48.2 to 41.2 cases/100,000 (P < .04). CONCLUSIONS: Implementing an organized CRC screening program in a large community-based population rapidly increased screening participation to the ≥80% target set by national organizations. Screening rates were sustainable and associated with substantial decreases in CRC incidence and mortality within short time intervals, consistent with early detection and cancer prevention.

Index colonoscopy-related risk factors for postcolonoscopy colorectal cancers.

BACKGROUND AND AIMS: Postcolonoscopy colorectal cancers (PCCRCs) are defined as those detected ≤10 years after an index colonoscopy negative for cancer, but modifiable risk factors are not well established in large, community-based populations. METHODS: We evaluated risk factors from the index colonoscopy for PCCRCs diagnosed 1 to 10 years after an index colonoscopy using a case-control design. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for potential confounders. RESULTS: A proximal polyp ≥10 mm (OR, 8.18; 95% CI, 4.59-14.60), distal polyp ≥10 mm (OR, 3.30; 95% CI, 1.65-6.58), adenoma with (OR, 3.23; 95% CI, 1.83-5.68) and without advanced histology (OR, 1.87; 95% CI, 1.37-2.55), and an incomplete colonoscopy (OR, 5.52; 95% CI, 2.98-10.21) were associated with PCCRC. Risk factors for early versus late cancers (12-36 months vs >36 months to 10 years after examination) included incomplete polyp excision in the colonic segment of the subsequent cancer (OR, 4.76; 95% CI, 2.35-9.65); failure to examine the segment (OR, 2.42; 95% CI, 1.27-4.60); and a polyp ≥10 mm in the segment (OR, 2.38; 95% CI, 1.53-3.70). A total of 559 of 1206 patients with PCCRC (46.4%) had 1 or more risk factors that were significant for PCCRC (incomplete examination, large polyp, or any adenoma). CONCLUSIONS: In a large community-based study with comprehensive capture of PCCRCs, almost half of PCCRCs had potentially modifiable factors related to polyp surveillance or removal and examination completeness. These represent potential high-yield targets to further increase the effectiveness of colorectal cancer screening.

Accurate Identification of Colonoscopy Quality and Polyp Findings Using Natural Language Processing.

OBJECTIVES: The aim of this study was to test the ability of a commercially available natural language processing (NLP) tool to accurately extract examination quality-related and large polyp information from colonoscopy reports with varying report formats. BACKGROUND: Colonoscopy quality reporting often requires manual data abstraction. NLP is another option for extracting information; however, limited data exist on its ability to accurately extract examination quality and polyp findings from unstructured text in colonoscopy reports with different reporting formats. STUDY DESIGN: NLP strategies were developed using 500 colonoscopy reports from Kaiser Permanente Northern California and then tested using 300 separate colonoscopy reports that underwent manual chart review. Using findings from manual review as the reference standard, we evaluated the NLP tool's sensitivity, specificity, positive predictive value (PPV), and accuracy for identifying colonoscopy examination indication, cecal intubation, bowel preparation adequacy, and polyps ≥10 mm. RESULTS: The NLP tool was highly accurate in identifying examination quality-related variables from colonoscopy reports. Compared with manual review, sensitivity for screening indication was 100% (95% confidence interval: 95.3%-100%), PPV was 90.6% (82.3%-95.8%), and accuracy was 98.2% (97.0%-99.4%). For cecal intubation, sensitivity was 99.6% (98.0%-100%), PPV was 100% (98.5%-100%), and accuracy was 99.8% (99.5%-100%). For bowel preparation adequacy, sensitivity was 100% (98.5%-100%), PPV was 100% (98.5%-100%), and accuracy was 100% (100%-100%). For polyp(s) ≥10 mm, sensitivity was 90.5% (69.6%-98.8%), PPV was 100% (82.4%-100%), and accuracy was 95.2% (88.8%-100%). CONCLUSION: NLP yielded a high degree of accuracy for identifying examination quality-related and large polyp information from diverse types of colonoscopy reports.