Table 2.
Association between hair dye use and prostate cancer risk in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study (1985–2012)a
| Hair category | No. of cases / No. of participants | HR (95% CI) | P-value |
|---|---|---|---|
| No grey hair | 466 / 5,163 | 1.0 (reference) | |
| Some grey hair | 1,378 / 13,841 | 1.09 (0.98–1.21) | 0.11 |
| More grey hair | 792 / 9,150 | 0.94 (0.83–1.06) | 0.29 |
| Bald | 52 / 566 | 1.06 (0.80–1.41) | 0.68 |
| Dyed hair | 13 / 75 | 1.81 (1.04–3.14) | 0.04 |
a
Adjusted for age, number of cigarettes smoked per day, years of smoking, and family history of prostate cancer
Abbreviations: CI: confidence interval; HR: hazard ratio