Table 2.
Association between risk factors and age at pancreatic cancer diagnosis among cases (N = 134). HRs estimate earlier age at diagnosis, not incident disease risk
| Variable | Model 1 | Model 2 | ||
|---|---|---|---|---|
| HR (95% CI) | p value | HR (95% CI) | p value | |
| Sex | ||||
| Male | Reference | Reference | ||
| Female | 1.80 (1.14–2.85) | 0.012 | 2.28 (1.45–3.56) | < 0.001 |
| Education (years) | 1.11 (1.07–1.16) | < 0.001 | 1.11 (1.07–1.16) | < 0.001 |
| Family history of pancreatic cancer | ||||
| No | Reference | Reference | ||
| Yes | 1.28 (0.51–3.22) | 0.606 | 1.30 (0.51–3.33) | 0.581 |
| Average exercise intensity a | 0.62 (0.34–1.12) | 0.114 | 0.54 (0.30–0.95) | 0.033 |
| Cigarette smoking | ||||
| Never | Reference | - | - | |
| Former | 0.98 (0.58–1.68) | 0.949 | - | - |
| Current | 2.71 (1.52–4.82) | < 0.001 | - | - |
| Alcohol consumption | ||||
| Never | Reference | - | - | |
| Former | 1.67 (0.95–2.94) | 0.077 | - | - |
| Current | 1.61 (0.87–2.96) | 0.129 | - | - |
| Diet index b | 2.19 (1.64–2.91) | < 0.001 | - | - |
| Chemical index c | 0.69 (0.52–0.93) | 0.016 | 0.86 (0.66–1.12) | 0.257 |
| Combined exposure index d | ||||
| 0 | - | - | Reference | |
| 1 | - | - | 1.79 (1.14–2.81) | 0.011 |
| 2 | - | - | 2.97 (1.67–5.28) | < 0.001 |
| 3 | - | - | 6.66 (3.35–13.22) | < 0.001 |
Abbreviations: CI = confidence interval; HR = hazard ratio; N = number of participants; WQS = weighted quantile sum. HR > 1 indicates earlier age at diagnosis among pancreatic cancer cases and should not be interpreted as incident disease risk
a Time-weighted average exercise score from age 15 to current age (0 = never, 0.5 = intermittent, 1 = consistent), averaged across observed years
b Dietary index constructed using grouped weighted quantile sum (WQS) regression of ten two-year variables (Chinese medicine use and nine food items), standardized to weekly servings, percentile-normalized (0–100), higher values = greater intake
c Chemical exposure index constructed using grouped WQS regression of ten variables (e.g., pesticide, metal, degreaser, incense), harmonized to annual frequency, imputed if missing, percentile-normalized (0–100), higher values = greater cumulative exposure
d Combined exposure index was constructed as the sum of three binary indicators—cigarette smoking (current or former = 1, never = 0), alcohol consumption (current or former = 1, never = 0), and dietary pattern (above the cohort median = 1, at or below = 0). The index ranged from 0 to 3, with 0 = none, 1 = single, 2 = double, and 3 = triple exposure. In the Cox proportional hazards models, this index was entered as a categorical variable to estimate the association between cumulative adverse lifestyle exposures and earlier age at diagnosis among pancreatic cancer cases