Table 2.
Association between active smoking with breast tumor DNA methylation, premenopausal cases
| Active smoking age <21 |
Active smoking age 21 −30 |
Active smoking age 31–40 |
Active smoking age 41–50 |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SMK | N | ORa | (95% CI) | SMK | N | ORa | (95% CI) | SMK | N | ORa | (95% CI) | SMK | N | ORa | (95% CI) | ||||
| >M | <M | >M | <M | >M | <M | >M | <M | ||||||||||||
| SFN | |||||||||||||||||||
| No | 33 | 39 | 1.00 | (referent) | No | 33 | 38 | 1.00 | (referent) | No | 45 | 47 | 1.00 | (referent) | No | 43 | 50 | 1.00 | (referent) |
| Yes | 30 | 30 | 1.22 | (0.49; 3.00) | Yes | 30 | 31 | 1.07 | (0.40; 2.81) | Yes | 19 | 22 | 0.49 | (0.13; 1.89) | Yes | 10 | 12 | 0.96 | (0.26; 3.47) |
| SCGB3A1 | |||||||||||||||||||
| No | 43 | 20 | 1.00 | (referent) | No | 40 | 19 | 1.00 | (referent) | No | 50 | 29 | 1.00 | (referent) | No | 51 | 30 | 1.00 | (referent) |
| Yes | 32 | 26 | 0.25 | (0.09; 0.75) | Yes | 35 | 27 | 0.30 | (0.10; 0.91) | Yes | 25 | 18 | 0.55 | (0.16; 1.96) | Yes | 9 | 12 | 0.19 | (0.04; 0.81) |
| RARB | |||||||||||||||||||
| No | 38 | 31 | 1.00 | (referent) | No | 37 | 29 | 1.00 | (referent) | No | 50 | 39 | 1.00 | (referent) | No | 50 | 39 | 1.00 | (referent) |
| Yes | 37 | 24 | 1.29 | (0.51; 3.27) | Yes | 38 | 26 | 1.10 | (0.42; 2.89) | Yes | 25 | 17 | 0.96 | (0.31; 3.02) | Yes | 15 | 7 | 1.67 | (0.46; 5.98) |
| GSTP1 | |||||||||||||||||||
| No | 30 | 39 | 1.00 | (referent) | No | 31 | 37 | 1.00 | (referent) | No | 45 | 42 | 1.00 | (referent) | No | 44 | 46 | 1.00 | (referent) |
| Yes | 41 | 23 | 2.56 | (1.00; 6.58) | Yes | 40 | 25 | 1.98 | (0.73; 5.41) | Yes | 27 | 20 | 0.78 | (0.25; 2.44) | Yes | 18 | 8 | 1.78 | (0.55; 5.75) |
| CDKN2A | |||||||||||||||||||
| No | 29 | 30 | 1.00 | (referent) | No | 26 | 28 | 1.00 | (referent) | No | 36 | 38 | 1.00 | (referent) | No | 36 | 42 | 1.00 | (referent) |
| Yes | 34 | 25 | 1.49 | (0.54; 4.14) | Yes | 37 | 27 | 1.66 | (0.59; 4.65) | Yes | 27 | 18 | 1.94 | (0.59; 6.46) | Yes | 14 | 11 | 1.51 | (0.50; 4.62) |
| CCND2 | |||||||||||||||||||
| No | 21 | 19 | 1.00 | (referent) | No | 18 | 18 | 1.00 | (referent) | No | 24 | 24 | 1.00 | (referent) | No | 24 | 27 | 1.00 | (referent) |
| Yes | 16 | 23 | 0.69 | (0.18; 2.62) | Yes | 19 | 24 | 1.09 | (0.29; 4.01) | Yes | 13 | 19 | 0.90 | (0.20; 4.13) | Yes | 5 | 9 | 0.66 | (0.14; 3.03) |
| BRCA1 | |||||||||||||||||||
| No | 40 | 43 | 1.00 | (referent) | No | 38 | 43 | 1.00 | (referent) | No | 55 | 50 | 1.00 | (referent) | No | 49 | 56 | 1.00 | (referent) |
| Yes | 29 | 39 | 0.66 | (0.28; 1.53) | Yes | 31 | 39 | 0.77 | (0.32; 1.88) | Yes | 15 | 32 | 0.09 | (0.02; 0.38) | Yes | 9 | 14 | 0.60 | (0.19; 1.87) |
| FHIT | |||||||||||||||||||
| No | 14 | 22 | 1.00 | (referent) | No | 16 | 20 | 1.00 | (referent) | No | 20 | 26 | 1.00 | (referent) | No | 20 | 30 | 1.00 | (referent) |
| Yes | 15 | 17 | 1.50 | (0.43; 5.27) | Yes | 13 | 19 | 0.71 | (0.17; 2.97) | Yes | 9 | 13 | 0.80 | (0.13; 5.08) | Yes | 6 | 6 | 2.17 | (0.38; 12.41) |
| SYK | |||||||||||||||||||
| No | 41 | 42 | 1.00 | (referent) | No | 41 | 42 | 1.00 | (referent) | No | 53 | 54 | 1.00 | (referent) | No | 53 | 52 | 1.00 | (referent) |
| Yes | 40 | 31 | 1.42 | (0.60; 3.37) | Yes | 40 | 31 | 1.45 | (0.57; 3.67) | Yes | 29 | 19 | 2.78 | (0.83; 9.31) | Yes | 18 | 10 | 1.80 | (0.58; 5.65) |
a
Odds ratios (OR) for methylation above the median value and 95% confidence intervals (CI) were estimated with unconditional logistic regression model adjusted for age in years, lifetime pack-years, and estrogen receptor status. Abbreviations: Smk, smoking; M, median; OR, odds ratio; SFN, stratifin; SCGB3A1, secretoglobin, family 3A, member 1; RARB , retinoic acid receptor, beta; GSTP1, glutathione S-transferase pi 1; CDKN2A, cyclin-dependent kinase inhibitor 2A; CCND2, cyclin D2; BRCA1, breast cancer gene 1; FHIT, fragile histidine triad; SYK, spleen tyrosine kinase