Early-Onset Colorectal Cancer Incidence, Staging, and Mortality in Canada: Implications for Population-Based Screening

Abstract

INTRODUCTION: The incidence of early-onset colorectal cancer (eoCRC) has been increasing in North America. Debate remains as to whether the trends by topography, histology, stage, or mortality in this population are amenable to intervention from screening. METHODS: CRC incidence (2000-2017) and mortality (2000-2018) data were obtained from the Canadian Cancer Registry and Vital Statistics. Annual percentage changes (APC) in the incidence (topography and histology) and mortality of eoCRC were estimated using joinpoint regression. Incidence of latestage CRC (III or IV) versus early-stage CRC (I or II) was compared between the eoCRC (age 20-49 years) and eligible screening (age 50-74 years) groups with Poisson regression. RESULTS:Among women aged 20-49 years, the incidence of CRC significantly increased from 2000 to 2017 in both the distal colon (APC 5 1.40) and rectum (APC 5 3.00), whereas for men aged 20-49 years, the CRC incidence increased in the proximal colon (APC 5 1.10), distal colon (APC 5 3.00), and rectum (APC 5 3.70). Among both men and women aged 20-49 years, the incidence of nonmucinous adenocarcinomas significantly increased (APC: 1.90 and 2.30, respectively), whereas mucinous adenocarcinomas decreased for women (APC 5 21.60) and remained stable for men. Adults aged 30 to 49 years, when diagnosed with CRC, had a significantly higher risk of being diagnosed with a late-stage CRC compared with those in the age group of 50-74 years. Rectal cancer mortality increased from 2000 to 2018 in the eoCRC group (APC for women and men 3.80 and 3.40, respectively).

Global cancer statistics 2022: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries

“…The declines in colorectal cancer incidence in many high‐incidence countries over the last decades have been considered the result of population‐level shifts toward a healthier lifestyle (e.g., increased access to sources of fiber, such as fruits and vegetables) and the introduction of screening, 63,70 with the uptake of colonoscopy screening and the removal of precursor lesions attributed to the specific downturns in incidence rates from the late 1990s where implemented 71–73 . In contrast to the recent stabilizing or declining trends for all ages combined, there are numerous recent reports documenting a rise in colorectal cancer among younger adults (younger than 50 years at diagnosis) in many high‐income countries, including the United States, Canada, and Australia, with incidence rising by 1%–4% per year 74–81 …”

“…[71][72][73] In contrast to the recent stabilizing or declining trends for all ages combined, there are numerous recent reports documenting a rise in colorectal cancer among younger adults (younger than 50 years at diagnosis) in many high-income countries, including the United States, Canada, and Australia, with incidence rising by 1%-4% per year. [74][75][76][77][78][79][80][81] Reasons for the rising incidence in successive recent generations are unknown but point to a profound influence of risk factors during early life or/and young adulthood. Suspected risk factors include a rise in the prevalence of obesity, physical inactivity, and antibiotics affecting the gut microbiome.…”

Associations of advanced age with comorbidity, stage and primary subsite as contributors to mortality from colorectal cancer

“…Even though rectal cancer has lower all-cause mortality, the cancer-specific mortality is significantly higher in our analysis. Some studies have reported that unlike colon cancer, rectal cancer mortality has an increasing trend in some countries including Australia, Canada and the United States and needs to be further investigated ( 35 , 36 ). It is also shown that even though older people are experiencing higher mortality and the number of CRC deaths is going to rise because of the growing incidence rates; age groups younger than 50 are the only ones with an increasing projection of CRC mortality and more studies are needed in this area ( 37 , 38 ).…”

Association of Reducing the Recommended Colorectal Cancer Screening Age With Cancer Incidence, Mortality, and Costs in Canada Using OncoSim

“…In response to increasing CRC incidence in younger adults and updated decision-analysis modeling, several US organizations recommend initiating screening at age 45 rather than 50 years in average-risk Americans . Canadian data reveal similar rising early-onset CRC rates, suggesting a potential role for expansion of screening eligibility in Canada …”

“…[4][5][6][7] Canadian data reveal similar rising earlyonset CRC rates, suggesting a potential role for expansion of screening eligibility in Canada. 2,8 Modeling studies have demonstrated incidence and mortality benefit in screening beginning at age 50 years, 9,10 but there is a lack of Canadian literature assessing CRC screening before age 50 years. These economic data are essential in the context of the Canadian single-payer health care system.…”