Summary of meta-analysis and pooled analysis of smoking pack-years, NAT2 acetylators status, menopausal status and breast cancer risk
| Type of analysis | Pack-years* | NAT2 slow acetylators | NAT2 rapid acetylators | ||
| Premenopausal | Postmenopausal | Premenopausal | Postmenopausal | ||
| RR (95% CI) | RR (95% CI) | RR (95% CI) | RR (95% CI) | ||
| Meta-analysis | Never active | 1.00 | 1.00 | 1.00 | 1.00 |
| <20 | 1.21 (1.00 to 1.45) | 1.28 (1.08 to 1.50) | 1.00 (0.80 to 1.24) | 1.12 (0.93 to 1.36) | |
| ≥20 | 1.47 (1.08 to 2.01) | 1.41 (1.15 to 1.72) | 1.34 (0.94 to 1.89) | 0.98 (0.77 to 1.26) | |
| Pooled analysis | Never active | 1.00 | 1.00 | 1.00 | 1.00 |
| <20 | 1.05 (0.86 to 1.28) | 1.23 (1.03 to 1.46) | 0.91 (0.72 to 1.16) | 1.10 (0.89 to 1.35) | |
| ≥20 | 1.49 (1.08 to 2.04) | 1.42 (1.16 to 1.74) | 1.29 (0.89 to 1.86) | 0.88 (0.69 to 1.13) | |
Bold type indicates statistically significant increases in summary risk.
Source: Ambrosone et al.14
↵* Pack-years as a categorical variable were available from the following eight studies for meta-analysis: Ambrosone et al., 1996; Morabia et al., 2000; Chang-Claude et al., 2002; Egan et al., 2003; van der Hel et al., 2003; Alberg et al., 2004; Sillanpaa et al., 2005; Lissowska et al., 2006. Pack-years as a categorical variable were available from the following six studies for the pooled analysis: Ambrosone et al., 1996; Morabia et al., 2000; Chang-Claude et al., 2002; Egan et al., 2003; van der Hel et al., 2003; Lissowska et al., 2006.