O-57 Occupational exposure to endocrine disruptors and colorectal cancer risk in two Canadian cohorts
Bibliographic record
Abstract
Introduction Sex hormones have been implicated in the etiology of colorectal cancer. Endocrine disruptors (EDCs) are compounds that can interfere with sex hormone signalling and cause adverse health effects, including cancer. Exposure to EDCs is ubiquitous, but exposure in some workplaces occurs at much higher levels than in the general population. Objective To determine whether occupational exposure to EDCs is associated with colorectal cancer risk. Material and Methods A case-cohort study was nested in the Alberta’s Tomorrow Project (ATP) and in the Ontario Health Study (OHS). Incident cases of colorectal cancer were identified (NATP=202, NOHS=605); a sub-cohort of 3,464 participants was selected at baseline (NATP=565, NOHS=2,899). Occupational exposure to 17 EDCs was estimated via linkage to CANJEM, a job-exposure matrix, for participants’ longest-held job. Specifically, CANJEM provides a frequency-weighted intensity metric of exposure and it was used to categorize participants into never exposed, exposed and substantially exposed to each individual EDC. Multivariable logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (CI) for colorectal cancer associated with occupational exposure to EDCs while controlling for confounders identified using a directed acyclic graph. Results In ATP, exposure to arsenic (OR=2.86, 95%CI: 1.06–7.63), copper (OR=0.53, 95%CI: 0.29–0.92), lead (OR=0.58, 95%CI: 0.34–0.97) and substantial exposure to arsenic (OR=2.87, 95%CI: 1.01–1.80), phenol (OR=0.25, 95%CI: 0.08–0.61), and trichloroethylene (OR=0.45, 95%CI: 0.21–0.90) were associated with colorectal cancer. In OHS, exposure to polychlorinated biphenyls (OR=3.95, 95%CI: 1.82–8.55), styrene (OR=0.47, 95%CI: 0.26–0.79), and substantial exposure to aluminum (OR=1.32, 95%CI: 1.03–1.68), cadmium (OR=0.59, 95%CI: 0.38–0.87), lead (OR=1.29, 95%CI: 1.03–1.60), phthalates (OR=0.52, 95%CI: 0.25–0.96), and trichloroethylene (OR=1.43, 95%CI: 1.08–1.88) were associated with colorectal cancer. Conclusion Of the 17 EDCs, five were associated with an increased risk, and seven with a decreased colorectal cancer risk; however, none of the associations were consistent between the two cohorts.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.002 | 0.004 |
| Science and technology studies | 0.004 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 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".