Time Trends in Colorectal Cancer Incidence From 1992 to 2016 and Colorectal Cancer Mortality From 1980 to 2018 by Age Group and Geography in Canada.

INTRODUCTION: Several reports have highlighted increasing colorectal cancer (CRC) incidence among younger individuals. However, little is known about variations in CRC incidence or mortality across age subgroups in different geographical locations. We aimed to examine time trends in CRC incidence and mortality in Canada by age group and geography in this population-based, retrospective cohort study. METHODS: Individuals diagnosed with CRC from 1992 to 2016 or who died of CRC from 1980 to 2018 in Canada were studied. Geography was determined using an individual's postal code at diagnosis from the Canadian Cancer Registry or province or territory of death from the Canadian Vital Statistics Death Database. Geography was categorized into Atlantic, Central, Prairies, West, and Territories. Canadian Cancer Registry data were used to determine CRC incidence from 1992 to 2016. Canadian Vital Statistics Death data were used to determine CRC mortality from 1980 to 2018. RESULTS: Among all age groups, CRC incidence was highest in Atlantic Canada, was lowest in Western Canada, and increased with age. CRC incidence increased over time for individuals aged 20-44 years and was stable or decreased for other age groups in all regions. CRC mortality was highest in Atlantic Canada and lowest in the Prairies and Western Canada. CRC mortality decreased for individuals in all age groups and regions except among individuals aged 20-49 years in the Territories. DISCUSSION: Most of Canada has not yet seen an increase in CRC burden in the age group of 45-49 years, which is a reason to not lower the start age for CRC screening in Canada. Targeted CRC screening should be considered for individuals younger than 50 years who live in the Territories.

Evaluating the impact of the COVID-19 pandemic on cancer screening in a central Canadian province.

We evaluated the impact of COVID-19 on cancer screening in Manitoba, Canada using an interrupted time series (ITS) design and data from Manitoba's population-based, organized cancer screening programs from April 2020 to August 2021. In June 2020 (breast screening was suspended during April and May 2020), there was a 54% decrease between the predicted (i.e., observed data produced from regression models) and expected (i.e., counterfactual values produced for the COVID-19 period by assuming COVID-19 did not occur) number of screening mammograms (ratio = 0.46, 95% Confidence Interval (CI) 0.28-0.64). By December 2020, there was no significant difference between predicted and expected number of screening mammograms (ratio = 0.95, 95% CI 0.80-1.10). In April 2020, there was an 83% decrease in the number of Pap tests (ratio = 0.17, 95% CI 0.04-0.30). By January 2021, there was no significant difference between predicted and expected number of Pap tests (ratio = 0.93, 95% CI 0.81-1.06). In April 2020, there was an 81% decrease in the number of screening program fecal occult blood tests (FOBTs) (ratio = 0.19, 95% CI 0.0-0.44). By September 2020, there was no significant difference between predicted and expected number of FOBTs (ratio = 0.95, 95% CI 0.65-1.24). The estimated cumulative deficit (i.e., backlog) from April 2020 to August 2021 was 17,370 screening mammograms, 22,086 Pap tests, and 5253 screening program FOBTs. Overall, screening programs adapted quickly to the COVID-19 pandemic. Additional strategies may be needed to address remaining backlogs.

Continued increasing incidence of malignant appendiceal tumors in Canada and the United States: A population-based study.

BACKGROUND: To the authors' knowledge, there are limited data regarding the epidemiology of malignant appendiceal tumors. It remains unknown whether the previously reported trends are occurring in different countries and/or continuing in recent years and/or whether they are possibly due to increasing rates of appendectomies. In the current study, the authors investigated the patterns and time trends of malignant appendiceal tumor diagnosis by age group, sex, stage of disease, and histology in Canada and the United States and concomitant rates of appendectomies in Canada. METHODS: The Canadian Cancer Registry and the US Surveillance, Epidemiology, and End Results incidence databases were used to identify incident patients of malignant appendiceal tumors in the 2 countries between 1992 and 2016. The Canadian national hospitals Discharge Abstract Database was used to identify appendectomies performed between 2004 and 2015. Joinpoint regression analyses were performed to determine time trends. RESULTS: There was an overall increase in the incidence of malignant appendiceal tumors of 232% in the United States and 292% in Canada between 2000 and 2016. The increase was noted for malignant adenocarcinomas and neuroendocrine appendiceal tumors in both countries. The increase occurred across all age groups, sexes, and stages of disease. The highest rate of increase was noted for appendiceal neuroendocrine malignant tumors diagnosed among the youngest age groups. The rate of appendectomies was stable in the recent time periods, resulting in a decreasing rate of appendectomies per malignant appendiceal tumor diagnosis. CONCLUSIONS: The incidence of malignant appendiceal tumor is continuing to increase, which is not likely due to the increasing diagnosis of asymptomatic tumors at the time of appendectomies.

Longitudinal Rates of Colon Cancer Screening Use in Winnipeg, Canada: The Experience of a Universal Health-Care System with an Organized Colon Screening Program.

OBJECTIVES: We examined trends in colorectal cancer (CRC) screening (fecal occult blood test (FOBT), colonoscopy, and flexible sigmoidoscopy (FS)) and differences in CRC screening by income in a population with an organized CRC screening program and universal health-care coverage. METHODS: Individuals who had an FOBT, colonoscopy, or FS were identified from the provincial Physician Claims database and the population-based colon cancer screening registry. Trends in age-standardized rates were determined. Logistic regression was performed to explore the association between CRC screening and income quintiles by year. RESULTS: Up-to-date CRC screening (FOBT, colonoscopy, or FS) increased over time for men and women, all age groups, and all income quintiles. Up-to-date CRC screening was very high among 65- to 69- and 70- to 74-year-olds (70% and 73%, respectively). There was a shift toward the use of an FOBT for CRC screening for individuals in the lower income quintiles. The disparity in colonoscopy/FS coverage by income quintile was greater in 2012 than in 1995. Overall, there was no reduction in disparities by income in up-to-date CRC screening nor did the rate of increase in up-to-date CRC screening or FOBT use change after the introduction of the organized provincial CRC screening program. CONCLUSIONS: CRC screening is increasing over time for both men and women and all age groups. However, a disparity in up-to-date CRC screening by income persisted even with an organized CRC screening program in a universal health-care setting.

Performance measures related to colposcopy for canadian cervical cancer screening programs: identifying areas for improvement.

OBJECTIVE: To describe performance measures related to colposcopic examinations in Canadian cervical cancer screening programs; specifically, time to colposcopy, histological investigation rate, and agreement between cytology and histology. METHODS: As part of a national report on the performance of cervical cancer screening, aggregate provincial cervical cancer screening data provided by provinces to the Pan-Canadian Cervical Screening Network were used to evaluate colposcopy program performance measures for women 20 to 69 years of age who had a Pap test in 2009 and 2010. RESULTS: A total of 37 523 women had a high-grade or more severe Pap test result. The proportion of women who had a colposcopy ≤ 90 days after their Pap test ranged from 30.9% to 51.5%. Fewer women 60 to 69 years of age had a colposcopy than women in younger age groups. The proportion of women who had a high-grade or more severe Pap test result and colposcopy who had a biopsy within 12 months ranged from 82.1% to 96.5%. The proportion of biopsy results that agreed with the Pap test result ranged from 59.5% to 82.1%. CONCLUSION: The time from having a high-grade Pap test result to undergoing colposcopy must be reduced to lower the risk of adverse outcomes and the stress associated with delayed follow-up. The agreement between screening cytology and histology meets the national target of ≥ 65%. Although six of 13 provinces and territories provided data for colposcopy-related performance measures, more information is needed to assess colposcopy services accurately at the national level.

Objectif : Décrire les mesures de rendement associées aux examens colposcopiques au sein des programmes canadiens de dépistage du cancer du col utérin (plus particulièrement : le délai avant le recours à la colposcopie, le taux d'exploration histologique et le taux de concordance des résultats cytologiques et histologiques). Méthodes : Dans le cadre d'un rapport national sur le rendement du dépistage du cancer du col utérin, les données agrégées provinciales sur ce dépistage qu'ont fournies les provinces à l'Initiative pancanadienne sur le dépistage du cancer du col de l'utérus ont été utilisées pour évaluer les mesures du rendement des programmes de colposcopie chez les femmes de 20 à 69 ans qui avaient subi un test de Pap en 2009 et en 2010. Résultats : En tout, 37 523 femmes avaient obtenu des résultats de test de Pap indiquant la présence d'une anomalie de haut grade histologique ou d'une anomalie plus grave. La proportion des femmes qui ont subi une colposcopie ≤ 90 jours à la suite de leur test de Pap se situait entre 30,9 % et 51,5 %. Moins de femmes du groupe d'âge des 60 à 69 ans ont subi une colposcopie, par comparaison avec les femmes des groupes d'âge plus jeunes. La proportion des femmes qui avaient obtenu des résultats de test de Pap indiquant la présence d'une anomalie de haut grade histologique ou d'une anomalie plus grave, qui ont subi une colposcopie et qui ont subi une biopsie dans un délai de 12 mois se situait entre 82,1 % et 96,5 %. La proportion des résultats de biopsie qui concordaient avec les résultats de test de Pap se situait entre 59,5 % et 82,1 %. Conclusion : Le délai entre l'obtention de résultats de test de Pap indiquant la présence d'une anomalie de haut grade histologique et la tenue d'une colposcopie se doit d'être réduit pour que l'on puisse abaisser le risque d'issues indésirables et le stress qui sont associés au report du suivi. Le taux de concordance des résultats cytologiques et histologiques atteint la cible nationale de ≥ 65 %. Bien que six des 13 provinces et territoires aient fourni des données sur les mesures de rendement associées à la colposcopie, plus de renseignements s'avèrent requis pour que l'on puisse évaluer avec précision les services de colposcopie au niveau national.

Mammography rates for breast cancer screening: a comparison of First Nations women and all other women living in Manitoba, Canada, 1999-2008.

INTRODUCTION: First Nations (FN) women historically have low rates of preventive care, including breast cancer screening. We describe the frequency of breast cancer screening among FN women living in Manitoba and all other Manitoba (AOM) women after the introduction of a provincial, organized breast screening program and explore how age, area of residence, and time period influenced breast cancer screening participation. METHODS: The federal Indian Registry was linked to 2 population-based, provincial data sources. A negative binomial model was used to compare breast cancer screening for FN women with screening for AOM women. RESULTS: From 1999 through 2008, 37% of FN and 59% of AOM women had a mammogram in the previous 2 years. Regardless of area of residence, FN women were less likely to have had a mammogram than AOM women (relative rate [RR] = 0.69 in the north, RR = 0.55 in the rural south, and RR = 0.53 in urban areas). CONCLUSIONS: FN women living in Manitoba had lower mammography rates than AOM women. To ensure equity for all Manitoba women, strategies that encourage FN women to participate in breast cancer screening should be promoted.

Reducing inequities in colorectal cancer screening in North America.

Colorectal cancer (CRC) is an important cause of mortality and morbidity in North America. Screening using a fecal occult blood test, flexible sigmoidoscopy, or colonoscopy reduces CRC mortality through the detection and treatment of precancerous polyps and early stage CRC. Although CRC screening participation has increased in recent years, large inequities still exist. Minorities, new immigrants, and those with lower levels of education or income are much less likely to be screened. This review provides an overview of the commonly used tests for CRC screening, disparities in CRC screening, and promising methods at the individual, provider, and system levels to reduce these disparities. Overall, to achieve high CRC participation rates and reduce the burden of CRC in the population, a multi-faceted approach that uses strategies at all levels to reduce CRC screening disparities is urgently required.

Measuring the impact of COVID-19 on cancer survival using an interrupted time series analysis.

BACKGROUND: Few studies have investigated the impact of the COVID-19 pandemic on cancer survival. Those studies that have included pandemic vs prepandemic comparisons can mask differences during different periods of the pandemic such as COVID-19 waves. The objective of this study was to investigate the impact of the COVID-19 pandemic on cancer survival using an interrupted time series analysis and to identify time points during the pandemic when observed survival deviated from expected survival. METHODS: A retrospective population-based cohort study that included individuals diagnosed with cancer between January 2015 and September 2021 from Manitoba, Canada, was performed. Interrupted time series analyses with Royston-Parmar models as well as Kaplan-Meier survival estimates and delta restricted mean survival times at 1 year were used to compare survival rates for those diagnosed before and after the pandemic. Analyses were performed for 11 cancer types. RESULTS: Survival at 1 year for most cancer types was not statistically different during the pandemic compared with prepandemic except for individuals aged 50-74 years who were diagnosed with lung cancer from April to June 2021 (delta restricted mean survival times = -31.6 days, 95% confidence interval [CI] = -58.3 to -7.2 days). CONCLUSIONS: With the exception of individuals diagnosed with lung cancer, the COVID-19 pandemic did not impact overall 1-year survival in Manitoba. Additional research is needed to examine the impact of the pandemic on long-term cancer survival.

Steroid-Induced Hyperglycemia and Its Effect on Outcomes of R-CHOP Chemotherapy for Diffuse Large B-Cell Lymphoma.

Large doses of steroids are integral to R-CHOP, a first-line systemic therapy for diffuse large B-cell lymphoma (DLBCL), an aggressive form of non-Hodgkin Lymphoma (NHL). Patients on R-CHOP often develop clinically significant hyperglycemia from steroids. There is evidence of harms from steroid-induced hyperglycemia in the context of chemotherapy which are associated with a reduction in overall survival. The objective of our study was to characterize the effect of steroid-induced hyperglycemia on the outcomes of R-CHOP chemotherapy for DLBCL. METHODS: We performed a retrospective chart review of 188 patients with DLBCL treated with R-CHOP through CancerCare Manitoba (CCMB) from 1 January 2010 to 31 December 2014. Patients diagnosed with DLBCL were identified using the Manitoba Cancer Registry. The CCMB electronic medical record was reviewed to examine the association between steroid-induced hyperglycemia and subsequent infection, including febrile neutropenic events and overall survival (OS). RESULTS: Patients who developed hyperglycemia with steroid exposure became hyperglycemic during their first R-CHOP cycle. No significant differences in OS or rates of infection were found between euglycemic and hyperglycemic subjects. CONCLUSIONS: Patients destined to develop steroid-induced hyperglycemia declare themselves early in the course of steroid exposure. No statistically significant reduction in overall survival attributable to steroid-induced hyperglycemia was found.

New Cancer Diagnoses Before and During the COVID-19 Pandemic.

Importance: Disruptions to health care during the COVID-19 pandemic may have led to missed cancer diagnoses. It is critical to evaluate the association between the COVID-19 pandemic and cancer incidence to address public and patient anxiety, inform recovery efforts, and identify strategies to reduce the system's vulnerability to future disruptions. Objective: To examine the association between the COVID-19 pandemic and cancer incidence in Manitoba, Canada. Design, Setting, and Participants: A population-based cross-sectional study design was conducted using data from the Manitoba Cancer Registry and an interrupted time-series analysis. All individuals diagnosed with cancer in Manitoba, Canada, from January 1, 2015, until December 31, 2021, were included. Individuals diagnosed with breast, colon, rectal, or lung cancer were grouped by age as follows: younger than 50 years, 50 to 74 years, and 75 years and older. Exposures: COVID-19 pandemic. Main Outcomes and Measures: Age-standardized cancer incidence rates and the estimated cumulative difference between the number of cases in the absence of COVID-19 and observed (fitted) number of cancer cases. Results: A total of 48 378 individuals were included. The median (IQR) age at diagnosis was 68 (59-77) years and 23 972 participants (49.6%) were female. In April 2020, there was a 23% decrease in overall cancer incidence. Cancer incidence decreased by 46% for breast, 35% for colon, 47% for rectal, 50% for head and neck, 65% for melanoma, and 33% for endocrine cancer diagnoses and increased by 12% for hematological cancer diagnoses and 8% for diagnoses of cancers with an unknown primary site. Lung cancer incidence remained stable until December 2020 when it decreased by 11%. Brain and central nervous system and urinary cancer diagnoses decreased consistently over time from April 2020 to December 2021 by 26% and 12%, respectively. No association was observed with gynecologic (1% increase), other digestive (1% decrease), or pancreatic (7% increase) cancer incidence. As of December 2021, Manitoba had an estimated deficit of 692 (5.3%) cancers. The largest estimated deficits were for breast (273 cases, 14.1% deficit), colon (133 cases, 12.2% deficit), and lung cancers (132 cases, 7.6% deficit). Conclusions and Relevance: In this study, the COVID-19 pandemic was associated with an initial decrease in cancer diagnosis incidence followed by a recovery for most cancer sites. However, the cumulative deficit for some cancers with high fatality needs immediate attention.

Factors Associated with the Breast Cancer Diagnostic Interval across Five Canadian Provinces: A CanIMPACT Retrospective Cohort Study.

The cancer diagnostic process can be protracted, and it is a time of great anxiety for patients. The objective of this study was to examine inter- and intra-provincial variation in diagnostic intervals and explore factors related to the variation. This was a multi-province retrospective cohort study using linked administrative health databases. All females with a diagnosis of histologically confirmed invasive breast cancer in British Columbia (2007-2010), Manitoba (2007-2011), Ontario (2007-2010), Nova Scotia (2007-2012), and Alberta (2004-2010) were included. The start of the diagnostic interval was determined using algorithms specific to whether the patient's cancer was detected through screening. We used multivariable quantile regression analyses to assess the association between demographic, clinical and healthcare utilization factors with the diagnostic interval outcome. We found significant inter- and intra-provincial variation in the breast cancer diagnostic interval and by screen-detection status; patients who presented symptomatically had longer intervals than screen-detected patients. Interprovincial diagnostic interval variation was 17 and 16 days for screen- and symptom-detected patients, respectively, at the median, and 14 and 41 days, respectively, at the 90th percentile. There was an association of longer diagnostic intervals with increasing comorbid disease in all provinces in non-screen-detected patients but not screen-detected. Longer intervals were observed across most provinces in screen-detected patients living in rural areas. Having a regular primary care provider was not associated with a shorter diagnostic interval. Our results highlight important findings regarding the length of the breast cancer diagnostic interval, its variation within and across provinces, and its association with comorbid disease and rurality. We conclude that diagnostic processes can be context specific, and more attention should be paid to developing tailored processes so that equitable access to a timely diagnosis can be achieved.

Cancer incidence during the COVID-19 pandemic by region of residence in Manitoba, Canada: A cancer registry-based interrupted time series study.

INTRODUCTION: Health care in Manitoba, Canada is divided into five regions, each with unique geographies, demographics, health care access, and health status. COVID-19-related restrictions and subsequent responses also differed by region. To understand the impact of the pandemic on cancer incidence in the context of these differences, we examined age-standardized cancer incidence rates by region over time before and after the COVID-19 pandemic. METHODS: We used a population-based quasi-experimental study design, population-based data, and an interrupted time series analysis to examine the rate of new cancer diagnoses before (January 2015 until December 2019) and after the start of COVID-19 and the interventions implemented to mitigate its impact (April 2020 until December 2021) by region. RESULTS: Overall cancer incidence differed by region and remained lower than expected in Winnipeg (4.6% deficit, 447 cases), Prairie Mountain (6.9% deficit, 125 cases), and Southern (13.0% deficit, 238 cases). Southern was the only region that had a significantly higher deficit in cases compared to Manitoba (ratio 0.92, 95% CI 0.86, 0.99). Breast and colorectal cancer incidence decreased at the start of the pandemic in all regions except Northern. Lung cancer incidence decreased in the Interlake-Eastern region and increased in the Northern region. Prostate cancer incidence increased in Interlake-Eastern. CONCLUSIONS: The impact of the COVID-19 pandemic on cancer incidence differed by region. The deficit in the number of cases was largest in the southern region and was highest for breast and prostate cancers. Cancer incidence did not significantly decrease in the most northern, remote region.

Ensuring a Successful Transition From Cytology to Human Papillomavirus-Based Primary Cervical Cancer Screening in Canada by Investigating the Psychosocial Correlates of Women's Intentions: Protocol for an Observational Study.

BACKGROUND: The human papillomavirus (HPV) test has emerged as a significant improvement over cytology for primary cervical cancer screening. In Canada, provinces and territories are moving toward implementing HPV testing in cervical cancer screening programs. Although an abundance of research exists on the benefits of HPV-based screening, there is a dearth of research examining women's understanding of HPV testing. In other countries, failure to adequately address women's concerns about changes has disrupted the implementation of HPV-based screening. OBJECTIVE: The aims of the multipart study described in this paper are to develop psychometrically valid measures of cervical cancer screening-related knowledge, attitudes, and beliefs; to examine the feasibility of a questionnaire examining psychosocial factors related to HPV-based screening; and to investigate psychosocial correlates of women's intentions to participate in HPV-based screening. METHODS: We conducted a web-based survey (study 1) of Canadian women to assess the acceptability and feasibility of a questionnaire, including the validation of scales examining cervical cancer knowledge, HPV testing knowledge, HPV testing attitudes and beliefs, and HPV test self-sampling attitudes and beliefs. Preferences for cervical cancer screening were assessed using the best-worst scaling methodology. A second web-based survey (study 2) will be administered to a national sample of Canadian women between June 2022 and July 2022 using the validated scales. Differences in the knowledge, attitudes, beliefs, and preferences of women who are currently either underscreened or adequately screened for cervical cancer will be examined through bivariate analyses. Multinomial logistic regression will be used to estimate the associations between psychosocial and sociodemographic factors and intentions to undergo HPV-based screening. RESULTS: Between October 2021 and November 2021, a total of 1230 participants completed the questionnaire in study 1, and 1027 (83.49%) responses were retained after data cleaning methods were applied. Feasibility was comparable with similar population-based surveys in terms of survey length, participant attrition, and the number of participants excluded after data cleaning. As of May 2022, analysis of study 1 is ongoing, and results are expected to be published in the summer of 2022. Data collection is expected to begin for study 2 in the summer of 2022. Results are expected to be published between late 2022 and early 2023. CONCLUSIONS: Findings will provide direction for Canadian public health authorities to align guidelines to address women's concerns and optimize the acceptability and uptake of HPV-based primary screening. Validated scales can be used by other researchers to improve and standardize the measurement of psychosocial factors affecting HPV test acceptability. Study results will be disseminated through peer-reviewed journal articles; conference presentations; and direct communication with researchers, clinicians, policy makers, media, and specialty organizations. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/38917.

Time Trends in Colorectal Cancer Incidence Rates by Income and Age at Diagnosis in Canada From 1992 to 2016.

Importance: Colorectal cancer (CRC) incidence rates among individuals younger than 50 years have been increasing in many countries, including Canada. Whether changes in CRC incidence rates over time are uniform across income and age groups remains unknown. Objective: To examine time trends in CRC incidence rates in Canada by area-level average household income by age group from 1992 to 2016. Design, Setting, and Participants: A population-based, retrospective cohort study was conducted including individuals aged 20 years or older diagnosed with CRC in Canada (excluding Québec) from 1992 to 2016. Data analysis was performed from February 27 to September 28, 2020. Exposures: Average household income was determined by linking an individual's postal code at diagnosis from the Canadian Cancer Registry to Canadian Census data. Average household income was then categorized into quintiles from Q1, the lowest income group, to Q5, the highest income group. Main Outcomes and Measures: Canadian Cancer Registry data were used to determine CRC incidence rates from 1992 to 2016. Results: There were 340 790 cases of CRC diagnosed from 1992 to 2016; 11 790 cases (3.5%) were diagnosed in individuals aged 20 to 44 years. Colorectal cancer incidence rates for individuals aged 20 to 44 years increased for all income quintiles, with higher incidence rates in the lower income quintiles. The ratio between the maximum and minimum CRC incidence rates was highest among the 20- to 29-year age group from 1992 to 1996 (ratio, 2.67; 95% CI, 1.47-4.83) and 2012 to 2016 (ratio, 2.00; 95% CI, 1.29-3.10). For individuals aged 45 to 49 years, CRC incidence rates increased only for individuals in the lower income quintiles (eg, incidence in Q1, 1992-1996 vs 2012-2016: 4.54 per 100 000 [95% CI, 4.05-5.03] vs 5.37 per 100 000 [95% CI, 4.91-5.83]), with higher incidence rates in the high income quintiles (eg, incidence rate for Q5 in 1992-1996: 5.92 per 100 000 [95% CI, 5.36-6.48]). For those aged 50 to 54 years, CRC incidence rates were stable for all income quintiles, with less variability between income quintiles. For individuals aged 55 to 74 years, CRC incidence rates were stable or decreased for all income quintiles (eg, incidence rate for age 55-59 years in Q5, 1992-1992 vs 2012-2016: 17.97 per 100 000 [95% CI, 16.76-19.18] vs 14.56 per 100 000 [95% CI, 13.80-15.32]), and there was less variability in the rates by income quintile, particularly from 2012 to 2016. After age 75 years, CRC incidence rates were stable or decreased (eg, incidence rate for age 75-79 years, 1992-1996 vs 2012-2016: 66.43 per 100 000 [65.00-67.87] vs 57.34 per 100 000 [56.24-58.45]), were highest for the lower income quintiles, and variability between income quintiles increased relative to younger age groups. Conclusions and Relevance: In this cohort study, trends in CRC incidence rates in Canada differed by age group and income quintile. These results suggest that, although population-based screening can reduce income disparities, targeted interventions and further research are needed to address the increasing CRC incidence rate among younger individuals in Canada, particularly in the lower income quintiles.

Evaluating the Impact of the COVID-19 Pandemic on New Cancer Diagnoses and Oncology Care in Manitoba.

Individuals with cancer are vulnerable to infection with SARS-CoV-2, the virus causing COVID-19. Physical distancing, the reallocation of health care resources, and the implementation of procedures to reduce the spread of COVID-19 may also have serious consequences for people with cancer. We evaluated the impact of COVID-19 on new cancer diagnoses and oncology care in Manitoba, Canada using an interrupted time series design and data from the Manitoba Cancer Registry and CancerCare Manitoba's (CCMB) electronic medical record. In April 2020, there was a 23% decrease in new cancer diagnoses, a 21% decrease in pathology reports, and a 43% reduction in surgical resections. There was no difference in new cancer diagnoses by August 2020, surgery by July 2020, and pathology reports by September 2020. From April 2020 to June 2021, there was a 13% decrease in radiotherapy (RT) fractions, an 18% decrease in UCC visits, and a 52% decrease in in-person visits. There was no change in intravenous chemotherapy visits per month, first RT visits, or overall patient visits. The impact of COVID-19 on shifts in the stage at diagnosis and survival will be assessed in future analyses.

Time Trends in the Diagnosis of Colorectal Cancer With Obstruction, Perforation, and Emergency Admission After the Introduction of Population-Based Organized Screening.

Importance: Up to 30% of patients with a diagnosis of colorectal cancer (CRC) present as an emergency (an intestinal obstruction, perforation, or emergency hospital admission) (OPE). There are limited data about the association of organized, population-based colorectal cancer screening with the rate of emergency presentations. Objective: To examine the association of CRC screening with OPE at cancer diagnosis and time trends in the rate of OPE after the start of organized CRC screening using a highly sensitive fecal occult blood test. Design, Setting, and Participants: A historical cohort study was conducted among 1861 individuals 52 to 74 years of age with a diagnosis of CRC from January 1, 2007, to December 31, 2015, who lived in Winnipeg, Manitoba, a province with universal health care and an organized CRC screening program. Statistical analysis was performed from January 22, 2019, to February 26, 2020. Exposures: Variables included prior CRC screening, era of diagnosis, cancer stage at diagnosis, tumor site in the colon, area level mean household income, primary care continuity of care, and comorbidity. Main Outcomes and Measures: The primary outcomes were defined as an OPE. Logistic regression was used to evaluate factors associated with OPE at CRC diagnosis. Trends over time were calculated using Joinpoint Regression. Results: From 2007 to 2015, 1861 individuals 52 to 74 years of age (1133 men; median age, 65.1 years [interquartile range, 60.0-70.3 years]) received a diagnosis of CRC in Winnipeg. Most individuals had good continuity of care and moderate comorbidities. Overall, 345 individuals (18.5%) had an OPE. The rate of emergency hospital admissions decreased significantly from 2007 (the start of the organized, province-wide CRC screening program) to 2015 (annual change, -7.1%; 95% CI, -11.3% to -2.8%; P = .01). There was no change in the rate of obstructions or perforations or stage IV CRCs. Individuals who were up to date for CRC screening were significantly less likely to receive a diagnosis of an OPE (odds ratio, 0.38; 95% CI, 0.28-0.50; P < .001). The results were similar after adding emergency department visits and stage IV CRC at diagnosis to the outcome. Conclusions and Relevance: This study suggests that the rate of emergency hospital admissions decreased over time for individuals who underwent CRC screening, but there was no change in the rate of obstructions and perforations. Individuals who were up to date for CRC screening were less likely to have a CRC diagnosis with an OPE.

Examining the Impact of First Nations Status on the Relationship Between Diabetes and Cancer.

Purpose: This population-based study examined the relationship between diabetes and cancer and determined if this relationship was influenced by First Nations (FN) status. Methods: In a matched case-cohort study, individuals 30-74 years of age diagnosed with diabetes during 1984-2008 in the province of Manitoba, Canada, with no cancer diagnosis before their diabetes diagnosis were matched to one diabetes-free control by age, sex, FN status, and residence. Flexible competing risk and Royston-Parmar regression models were used to compare cancer rates. Results: Overall, 72,715 individuals diagnosed with diabetes were matched to controls. In all age groups, diabetes was related to an increased risk of cancer. The relationship between diabetes and any type of cancer was not influenced by FN status (i.e., there was no interaction between the diagnosis of diabetes and people's FN status for any age group). The only significant interaction between diabetes and FN status was for kidney cancer for individuals 60-74 years of age; diabetes increased the risk of kidney cancer for all other Manitobans (AOMs) but not for FN. Conclusions: Diabetes increased the risk of cancer. The association was not modified by FN status except for kidney cancer where diabetes increased the risk for AOMs but not for FN.

Inter- and intra-provincial variation in screen-detected breast cancer across five Canadian provinces: a CanIMPACT study.

OBJECTIVE: Breast cancer screening aims to identify cancers in early stages when prognosis is better and treatments less invasive. We describe inter- and intra-provincial variation in the percentage of screen-detected cases under publicly funded healthcare systems and factors related to having screen- vs non-screen-detected breast cancer across five Canadian provinces. METHODS: Women aged 40+ diagnosed with incident breast cancer from 2007 to 2012 in five Canadian provinces were identified from their respective provincial cancer registries. Standardized provincial datasets were created linking screening, health administrative, and claims data. Province-specific logistic regression models were used to evaluate the association of demographic and healthcare utilization factors in each province with the odds of screen-detected cancer. RESULTS: There was significant inter- and intra-provincial variation by age. Screen detection ranged from 42% to 52% in ages 50-69 but women aged 50-59 had approximately 4-8% lower screen detection than those aged 60-69 in all provinces. Screening associations with income quintile and rurality varied across provinces. Those least likely to be screen-detected within a province were consistently in the lowest income quintile; OR ranged from 0.62-0.89 relative to highest income quintile/urban patients aged 50-69. Lack of visits to primary care 30 months prior to diagnosis was also consistently associated with lower odds of screen detection (OR range, 0.37-0.76). CONCLUSION: Breast cancer screen detection rates in the Canadian provinces examined are relatively high. Associations with income-rurality indicate a need for greater attention and/or targeted outreach to specific communities and/or provincial regions to improve access to breast cancer screening services intra-provincially.

Retention of screened women in the Manitoba Breast Screening Program.

BACKGROUND: The retention rate or the percentage of women who return to screening within 30 months of a previous screening is an important measure of screening success and the acceptability of the screening program to women. The objective of this study was to investigate variables associated with the retention of women 50 to 68 years of age who were screened by the Manitoba Breast Screening Program (MBSP) during 2002 and 2003. METHODS: All women screened by the MBSP in 2002 and 2003 who were eligible for rescreening in 2 years were included in the study. Data were extracted from the MBSP database which contains demographic, screening, diagnostic follow-up, and diagnosis information for all women screened by the program. Contingency tables, chi2 tests, and logistic regression were used to investigate variables that were associated with retention. RESULTS: Retention was related to screen type (first or return), screen result (normal or abnormal), family history of breast cancer (risk or no risk), education (less than grade 9 or some high school or more), and ethnicity (Asian, First Nations, other). Retention was not related to residence (rural or urban). CONCLUSIONS: Overall screening retention at the MBSP was 80% which meets national standards. However, additional efforts may be required to improve the retention rate of Asian and First Nations women as well as women who had an abnormal screening result or less than a grade 9 level of education.

Interval colorectal cancer rates after Hemoccult Sensa and survival by detection mode for individuals diagnosed with colorectal cancer in Winnipeg, Manitoba.

OBJECTIVE: To assess the performance of the Sensa fecal occult blood test (FOBT) in a population-based screening program. SETTING: Manitoba, Canada. METHODS: This historical cohort study included individuals 52 to 74 years of age diagnosed with colorectal cancer (CRC) from 2008 to 2013. CRCs were categorized by detection following a screening program FOBT (Sensa), non-program FOBT (non-Sensa), or no FOBT. Screening program CRCs were classified as program-detected, interval program, or non-compliant. Logistic regression was used to compare characteristics by detection mode. Cox regression adjusted for lead-time was used to examine the effect of detection mode on survival. RESULTS: 1,498 individuals were diagnosed with CRC; 132 (8.8%) had a screening program FOBT, 626 (41.8%) had a non-program FOBT, and 740 (49.4%) had no FOBT. Of the screening program FOBT CRCs, 72 were program-detected (54.5%), 42 were interval program (31.8%), and 18 were non-compliant (13.6%). Sensa interval cancer rate was 37.4% and sensitivity was 63.1% (95% Confidence Interval (CI): 54.3%-72.0%). The risk of death for individuals that had a non-program (Hazard ratio (HR) = 0.57, 95% CI:0.44-0.75) or a screening program FOBT (HR = 0.55, 95% CI:0.31-0.97) was lower than no FOBT. There was no significant difference in the risk of death for interval, non-compliant, and non-program CRCs compared to program-detected CRCs. Adjusting for lead time bias, sex, income quintile, tumour location, and age at diagnosis did not appreciably change the risk estimates. CONCLUSION: More than one-third of CRCs may not be detected by Sensa. There may be no difference in survival between CRC detected by Sensa and non-Sensa FOBTs.