Effect of Chronic Comorbidities on Follow-up Colonoscopy After Positive Colorectal Cancer Screening Results: A Population-Based Cohort Study.

INTRODUCTION: Fecal occult blood tests (FOBTs) are colorectal cancer screening tests used to identify individuals requiring further investigation with colonoscopy. Delayed colonoscopy after positive FOBT (FOBT+) is associated with poorer cancer outcomes. We assessed the effect of comorbidity on colonoscopy receipt within 12 months after FOBT+. METHODS: Population-based healthcare databases from Ontario, Canada, were linked to assemble a cohort of 50-74-year-old individuals with FOBT+ results between 2008 and 2017. The associations between comorbidities and colonoscopy receipt within 12 months after FOBT+ were examined using multivariable cause-specific hazard regression models. RESULTS: Of 168,701 individuals with FOBT+, 80.5% received colonoscopy within 12 months. In multivariable models, renal failure (hazard ratio [HR] 0.71, 95% confidence interval [CI] 0.62-0.82), heart failure (HR 0.77, CI 0.75-0.80), and serious mental illness (HR 0.88, CI 0.85-0.92) were associated with the lowest colonoscopy rates, compared with not having each condition. The number of medical conditions was inversely associated with colonoscopy uptake (≥4 vs 0: HR 0.64, CI 0.58-0.69; 3 vs 0: HR 0.75, CI 0.72-0.78; and 2 vs 0: HR 0.87, CI 0.85-0.89). Having both medical and mental health conditions was associated with a lower colonoscopy uptake relative to no comorbidity (HR 0.88, CI 0.87-0.90). DISCUSSION: Persons with medical and mental health conditions had lower colonoscopy rates after FOBT+ than those without these conditions. Better strategies are needed to optimize colorectal cancer screening and follow-up in individuals with comorbidities.

Periodic screening for breast and cervical cancer in women with diabetes: a population-based cohort study.

PURPOSE: Diabetes is associated with poorer cancer outcomes. Screening for breast and cervical cancer is recommended by clinical guidelines; however, utilization of these tests in people with diabetes has been unclear due to methodological limitations in the evidence base. We used administrative data to determine the association between diabetes and the rates of becoming up-to-date with periodic breast and cervical cancer screening over a 20-year period. METHODS: Healthcare databases from Ontario, Canada, were linked to assemble two population-based cohorts of 50-70 and 21-70 year-olds between 1994 and 2011, eligible for breast and cervical cancer screening, respectively. Using age as the time scale, multivariable recurrent events models were implemented to examine the association between the presence of diabetes and the rates of becoming up-to-date with the recommended cancer screenings. RESULTS: In each of the breast and cervical cancer screening cohorts, there were, respectively, 1,516,302 (16% had diabetes at baseline) and 4,751,220 (9.5% had diabetes at baseline) screen-eligible women. In multivariable models, prevalent diabetes (duration ≥ 2 years) was associated with lower rates of becoming up-to-date with cervical (hazard ratio, HR 0.85, 95% confidence interval, CI 0.84-0.85) and breast (HR 0.94, CI 0.93-0.94) cancer screening, compared to no diabetes. CONCLUSIONS: Having diabetes is associated with decreased rates of becoming up-to-date with two recommended periodic cancer screenings, with a bigger reduction in the rates of becoming up-to-date with cervical cancer screening. Greater attention to cervical cancer preventive services is needed in women with diabetes.

Influence of chronic comorbidities on periodic colorectal cancer screening participation: A population-based cohort study.

Guidelines recommend regular screening for colorectal cancer (CRC). We examined the effects of chronic comorbidities on periodic CRC testing. Using linked healthcare databases from Ontario, Canada, we assembled a population-based cohort of 50-74-year olds overdue for guideline-recommended CRC screening between April 1, 2004 and March 31, 2016. We implemented multivariable recurrent events models to determine the association between comorbidities and the rate of becoming up-to-date with periodic CRC tests. The cohort included 4,642,422 individuals. CRC testing rates were significantly lower in persons with renal disease on dialysis (hazard ratio, HR 0.66, 95% confidence interval, CI 0.63 to 0.68), heart failure (HR 0.75, CI 0.75 to 0.76), respiratory disease (HR 0.84, CI 0.83 to 0.84), cardiovascular disease (HR 0.85, CI 0.84 to 0.85), diabetes (HR 0.86, 95% CI 0.86 to 0.87) and mental illness (HR 0.88, CI 0.87 to 0.88). There was an inverse association between the number of medical conditions and the rate of CRC testing (5 vs. none: HR 0.30, CI 0.25 to 0.36; 4 vs. none: HR 0.48, CI 0.47 to 0.50; 3 vs. none: HR 0.59, CI 0.58 to 0.60; 2 vs. none: HR 0.72, CI 0.71 to 0.72; 1 vs. none: HR 0.85, CI 0.84 to 0.85). Having both medical and mental comorbidities was associated with lower testing rates than either type of comorbidity alone (HR 0.72, CI 0.71 to 0.72). In summary, chronic comorbidities present a barrier to periodic guideline-recommended CRC testing. Exploration of cancer prevention gaps in these populations is warranted.

Impact of diabetes on colorectal cancer stage and mortality risk: a population-based cohort study.

AIMS/HYPOTHESIS: Diabetes is associated with an increased incidence of colorectal cancer (CRC). There exists conflicting evidence regarding the impact of diabetes on CRC-specific mortality (herein also referred to as cancer-specific mortality). The objectives of this study were to determine whether diabetes is associated with a more advanced CRC stage at diagnosis and with higher all-cause and cancer-specific mortality. METHODS: This retrospective cohort study used linked, population-based health databases from Ontario, Canada. Among individuals diagnosed with CRC from 2007 to 2015, we compared the likelihood of presenting with later- (III or IV) vs early- (I or II) stage CRC between patients with and without diabetes adjusting for relevant covariates. We then determined the association between diabetes and all-cause and CRC-specific mortality, after adjusting for CRC stage at diagnosis and other covariates. RESULTS: Of the 44,178 individuals with CRC, 11,822 (26.7%) had diabetes. After adjustment for CRC screening and other covariates, individuals with diabetes were not more likely to present with later-stage CRC (adjusted OR 0.97, 95% CI 0.93, 1.01). Over a median follow-up of 2.63 (interquartile range [IQR] 0.97-5.10) years, diabetes was associated with higher all-cause mortality (adjusted HR 1.08, 95% CI 1.04, 1.12) but similar cancer-specific survival (adjusted HR 1.0, 95% CI 0.95, 1.06). CONCLUSIONS/INTERPRETATION: Individuals with diabetes who develop CRC are not more likely to present with a later stage of CRC and have similar cancer-specific mortality compared with those without diabetes. Diabetes was associated with higher all-cause mortality in CRC patients, indicating that greater attention to non-cancer care is needed for CRC survivors with diabetes.

Breast, cervical and colorectal cancer screening in adults with diabetes: a systematic review and meta-analysis.

AIMS/HYPOTHESIS: Individuals with diabetes are at increased risk of developing and dying from cancer. Evidence-based guidelines recommend universal screening for breast, cervical and colorectal cancer; however, evidence on the uptake of these tests in individuals with diabetes is mixed. We conducted a meta-analysis to quantify the association between diabetes and participation in breast, cervical and colorectal cancer screening. METHODS: MEDLINE, EMBASE and CINAHL were searched systematically for publications between 1 January 1997 and 18 July 2018. The search was supplemented by handsearching of reference lists of the included studies and known literature reviews. Abstracts and full texts were assessed in duplicate according to the following eligibility criteria: study conducted in the general population; diabetes included as a predictor vs a comparison group without diabetes; and breast (mammography), cervical (Papanicolaou smear) or colorectal (faecal and endoscopic tests) cancer screening uptake included as an outcome. Random-effects meta-analyses were performed using the most-adjusted estimates for each cancer site. RESULTS: Thirty-seven studies (25 cross-sectional, 12 cohorts) were included, with 27 studies on breast, 19 on cervical and 18 on colorectal cancer screening. Having diabetes was associated with significantly lower likelihood of breast (adjusted OR 0.83 [95% CI 0.77, 0.90]) and cervical (OR 0.76 [95% CI 0.71, 0.81]) cancer screening, relative to not having diabetes. Colorectal cancer screening was comparable across groups with and without diabetes (OR 0.95 [95% CI 0.86, 1.06]); however, women with diabetes were less likely to receive a colorectal cancer screening test than women without diabetes (OR 0.86 [95% CI 0.77, 0.97]). CONCLUSIONS/INTERPRETATION: Our findings suggest that women with diabetes have suboptimal breast, cervical and colorectal cancer screening rates, compared with women without diabetes, although the absolute differences might be modest. Given the increased risk of cancer in this population, higher quality prospective evidence is necessary to evaluate the contribution of diabetes to cancer screening disparities in relation to other patient-, provider- and system-level factors. REGISTRATION: PROSPERO registration ID CRD42017073107.