Table 1.
Associations between acetaminophen use and total cancer incidence, stratified by gender
| 10-year Use Prior to Baselinea | ||||
|---|---|---|---|---|
| No Use | Low Use | High Use | P trend | |
| All participants (n=62,841) | ||||
| Cases (n=5,750) | 4,467 (77.7%) | 978 (17.0%) | 305 (5.3%) | |
| Non-cases (n=57,091) | 44,467 (77.9%) | 9,671 (16.9%) | 2,953 (5.2%) | |
| HR (95% CI)b | 1.00 (reference) | 1.08 (0.99–1.17) | 1.02 (0.89–1.17) | 0.25 |
| Women (n=32,059) | ||||
| Cases (n=2,441) | 1,741 (71.3%) | 523 (21.4%) | 177 (7.3%) | |
| Non-cases (n=29,618) | 21,620 (73.0%) | 6,002 (20.3%) | 1,996 (6.7%) | |
| HR (95% CI)b | 1.00 (reference) | 1.04 (0.92–1.17) | 0.97 (0.80–1.17) | 0.97 |
| Men (n=30,782) | ||||
| Cases (n=3,309) | 2,726 (82.4%) | 455 (13.8%) | 128 (3.9%) | |
| Non-cases (n=27,473) | 22,847 (83.2%) | 3,669 (13.4%) | 957 (3.5%) | |
| HR (95% CI)b | 1.00 (reference) | 1.18 (0.99–1.26) | 1.08 (0.88–1.31) | 0.11 |
| P interaction = 0.88 | ||||
Low use, use for either less than 4 days/week or less than 4 years; high use, use for at least 4 days/week and at least 4 years.
A priori potential confounders were selected, including known and suspected cancer risk factors and medical conditions that may be indications for use of acetaminophen, for adjustment in multivariable regression models. Specifically, all models were adjusted for age, education, race, marital status, height, body mass index, physical activity, pack-years of smoking, alcohol intake at 45y, fruit and vegetable intake, red meat intake, multivitamin use, self-rated health, family history of colon, lung, and hematological cancers (as separate terms), sigmoidoscopy in the past 10 years, diabetes, osteoarthritis/chronic joint pain, migraine/chronic headaches, and use of non-steroidal anti-inflammatory drugs (NSAIDs). The models were additionally adjusted for family history of breast cancer, mammogram in the past 2 years, age at menarche, age at menopause, age at first birth, years of estrogen therapy, years of combined hormone therapy, and hysterectomy (for women); and family history of prostate cancer and PSA test in the past 2 years (for men).
Abbreviations: CI, confidence interval; HR, hazard ratio.