Increasing colorectal cancer incidence trends among younger adults in Canada
Bibliographic record
Abstract
Recent analyses in the United States have shown an overall decrease in the incidence of colorectal cancer despite contrasting increases in younger age groups. We examined whether these cohort trends are occurring in Canada. Age-specific trends in colon and rectal cancer incidence in Canada from the National Cancer Incidence Reporting System (1969-1992) and the Canadian Cancer Registry (1992-2012) were analyzed. We estimated annual percent changes (APC) with the Joinpoint Regression Program from the Surveillance Epidemiology, and End Results Program. Birth cohort effects were estimated using 5-year groups starting in 1888. Age-specific prevalence of class I, II and III obesity in Canada was examined from the National Population Health Survey (1994-2001) and the Canadian Community Health Survey (2001-2011). The reductions in CRC incidence among Canadians are limited to older populations. While reductions among younger age groups (20-29year olds (yo), 30-39yo and 40-50yo) were observed between 1969 and 1995, rates have returned to and surpassed historical levels (APCs 20-29yo colon cancer=6.24%, APCs 20-29yo rectal cancer=1.5%). Recent birth cohorts (1970-1990) have the highest incidence rate ratios ever recorded. Ecologic trends in obesity prevalence among these birth cohorts in Canada are suggestive of an impact on increasing incidence trends. Furthermore, obesity prevalence estimates suggest that these trends may continue to increase justifying further examination of the etiologic associations and biological impacts of excess adipose tissue among younger populations. While population-based screening of younger age groups deserves careful consideration, these concerning observed trends warrant public health action to address the growing obesity epidemic.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.003 | 0.006 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".