Table 2.

Association between allergies, asthma, and atopic disease and overall and site-specific cancer risk

CohortCaseMinimally adjustedaMultivariable adjustedb
N (%)N (%)HR (95% CI)HR (95% CI)
Overall cancerc
 Asthma
  No54,685 (85%)3,092 (86%)1.001.00
  Yes9,411 (15%)509 (14%)1.07 (0.97–1.17)1.02 (0.93–1.13)
 Allergies
  No48,358 (75%)2,797 (78%)1.001.00
  Yes15,749 (25%)803 (22%)0.93 (0.86–1.01)0.96 (0.88–1.04)
Lung cancerd
 Asthma
  No49,558 (85%)479 (82%)1.001.00
  Yes8,442 (15%)102 (18%)1.38 (1.11–1.72)1.25 (1.00–1.57)
 Allergies
  No43,688 (75%)471 (81%)1.001.00
  Yes14,316 (25%)109 (19%)0.75 (0.60–0.92)0.80 (0.65–1.00)
Breast cancere,f
 Asthma
  No29,700 (83%)431 (86%)1.001.00
  Yes6,220 (17%)70 (14%)0.84 (0.65–1.08)0.82 (0.63–1.05)
 Allergies
  No24,995 (70%)345 (69%)1.001.00
  Yes10,937 (30%)156 (31%)1.05 (0.86–1.27)1.01 (0.84–1.23)
Prostate cancerg,h
 Asthma
  No20,517 (90%)417 (90%)1.001.00
  Yes2,369 (10%)45 (10%)1.07 (0.79–1.46)1.07 (0.78–1.45)
 Allergies
  No19,213 (84%)393 (85%)1.001.00
  Yes3,672 (16%)69 (15%)0.95 (0.74–1.23)0.90 (0.69–1.17)
  • Abbreviations: HR (hazard ratio); 95% CI (95% confidence interval).

  • aAdjusted for age (time axis of analysis), sex, race/ethnicity (NHB, NHW, and other), and enrollment source (CHC vs. general population).

  • bAdjustment variables depend on the outcome of interest.

  • cAnalyses of overall cancer adjusted for factors listed in footnote “a” above, as well as household income (<15,000, 15,000–<25,000, 25,000–<50,000, or 50,000+), insurance status (uninsured vs. insured), time since last seen a doctor (<3 months, 3–<12 months, or 12 months+), BMI (<25, 25–<30, 30–<35, or 35+), history of smoking (never smoker, tertiles of pack-years smoked among former smokers, and tertiles of pack-years smoked among current smokers), alcohol intake (nondrinker, and categories of g/day: 0.1–<5, 5–<15, 15–<30, 30–<45, or 45+); moderate/vigorous physical activity (sex-specific quartiles of MET-hours/week); postmenopausal hormone use (premenopausal; postmenopausal and never use; or postmenopausal and ever use); family history of any cancer (none or any).

  • dAnalyses of lung cancer adjusted for factors listed in footnote “c” above, except for family history of any cancer. Instead, we adjusted for family history of lung cancer (none or any), as well as history of COPD.

  • eAnalyses of breast cancer limited to women.

  • fAnalyses of breast cancer adjusted for factors listed in footnote “c” above, except for sex and family history of any cancer. Instead, we adjusted for family history of breast cancer (none or any), as well as history of mammogram (never, not recent: >2 years, or recent: ≤2 years ago).

  • gAnalyses of prostate cancer limited to men.

  • hAnalyses of prostate cancer adjusted for factors listed in footnote “c” above, except for sex and family history of any cancer. Instead, we adjusted for family history of prostate cancer (none or any), as well as prostate-specific antigen screening (never, not recent: >2 years ago, or recent: ≤2 years ago), and history of digital rectal exam (never, not recent: >2 years ago, or recent: ≤2 years ago).