Table 3

Length of employment (in tertiles) in workplaces handling hazardous chemicals and risk of cancer among men in a hospital-based case–control study, Japan, 2005–2019

Cancer siteLength (in tertiles)*N of exposed casesOR†(95% CI)P for trend‡
All cancersShort6850.94(0.86 to 1.03)<0.01
Moderate13330.99(0.92 to 1.06)
Long24811.13(1.07 to 1.19)
LungShort1041.59(1.20 to 2.11)<0.01
Moderate2352.12(1.74 to 2.59)
Long3851.82(1.56 to 2.13)
OesophagusShort161.19(0.62 to 2.27)<0.01
Moderate381.77(1.09 to 2.87)
Long631.73(1.18 to 2.55)
StomachShort980.91(0.71 to 1.16)0.11
Moderate2150.95(0.80 to 1.13)
Long4051.15(1.01 to 1.32)
ColorectalShort1211.16(0.92 to 1.46)0.60
Moderate1920.94(0.79 to 1.13)
Long3190.96(0.84 to 1.11)
LiverShort320.84(0.54 to 1.30)0.33
Moderate841.05(0.78 to 1.41)
Long1240.87(0.68 to 1.10)
Biliary tractShort90.78(0.35 to 1.73)0.64
Moderate130.65(0.34 to 1.26)
Long461.25(0.81 to 1.91)
PancreasShort161.61(0.82 to 3.17)<0.01
Moderate341.53(0.95 to 2.46)
Long652.03(1.40 to 2.94)
BladderShort401.23(0.82 to 1.85)<0.01
Moderate821.44(1.06 to 1.94)
Long1551.40(1.12 to 1.74)
  • *The median (range) length of employment was 10 (1–17), 28 (18–34) and 41 (32–58) years for short, moderate and long, respectively.

  • †ORs and 95% CIs were calculated using conditional logistic regression with multiple imputation, matched for age categories (5-year categories), hospital (34 hospitals) and admitted year (1-year) with additional adjustment for smoking status, alcohol consumption status and longest occupation held (the reference categories were never exposed).

  • ‡Trend test was performed for the associations between exposed length as a continuous variable and cancer incidence.