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.

Impact of age, comorbidity, and polypharmacy on receipt of systemic therapy in advanced cancers: A retrospective population-based study.

INTRODUCTION: Cancer incidence, comorbidity, and polypharmacy increase with age, but the interplay between these factors on receipt of systemic therapy (ST) in advanced cancer has rarely been studied. MATERIALS AND METHODS: A retrospective cohort study was conducted including patients aged ≥18 years diagnosed from 2004 to 2015 with multiple myeloma (MM) (all stages), lung cancer (stage IV), and stage III-IV non-Hodgkin's lymphoma (NHL), breast, colorectal (CRC), prostate, or ovarian cancer in Manitoba, Canada. Clinical and administrative health data were used to determine demographic and cancer characteristics, treatment history, comorbidity (Charlson Comorbidity Index [CCI] and Resource Utilization Band [RUB]), and polypharmacy (≥6 medications). Multivariable logistic regression was used to evaluate variable associations with receipt of ST and interaction with age. RESULTS: In total, 17,228 patients were diagnosed with advanced cancer. Ages were distributed as follows: 7% <50 years, 16% 50-59 years, 26% 60-69, 26% 70-79, 24% ≥80 years. ST was administered to 50% of patients. Increased age, polypharmacy, and comorbidity each independently decreased the likelihood of receiving ST. Significant interaction effects were found between age at diagnosis with stage of cancer and cancer type. Differences in probability of ST by cancer stage converged as age increased. In multivariable analysis, adjusting for covariates, patients with MM had the highest odds and lung cancer the lowest odds to receive ST. The impact of comorbidity and polypharmacy did not differ meaningfully with increasing age. DISCUSSION: Increased age, polypharmacy, and comorbidity were each independently associated with decreased receipt of ST in people with advanced cancers. The impact of comorbidity and polypharmacy did not differ meaningfully with increasing age, while age meaningfully interacted with stage and cancer type.

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.