Table 5.
Pooled relative risks (RRs) and 95% confidence intervals (CIs) for the association between regular talc use and ovarian cancer risk, stratified by genotype, in the New England Case-Control Study (NECC) and the Nurses' Health Study (NHS)*†
| All cancers |
Serous invasive cancers |
Cases and controls in pooled analysis |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| All cases |
Serous inv. |
Controls |
||||||||
| Regular talc use | Regular talc use | Regular talc | Regular talc | Regular talc | ||||||
| No | Yes | No | Yes | No | Yes | No | Yes | No | Yes | |
| Gene/stratum | ||||||||||
| GSTM1 genotype | ||||||||||
| Present (+) | 1.0 (ref.) | 1.6 (1.2, 2.0) | 1.0 (ref.) | 2.0 (1.4, 2.8) | 480 | 189 | 173 | 90 | 646 | 165 |
| Null (-) | 1.0 (ref.) | 1.3 (1.0, 1.6) | 1.0 (ref.) | 1.4 (1.0, 1.9) | 498 | 179 | 190 | 76 | 690 | 198 |
| P-interaction§ | 0.13 | 0.08 | ||||||||
| GSTT1 genotype | ||||||||||
| Present (+) | 1.0 (ref.) | 1.2 (1.0, 1.5) | 1.0 (ref.) | 1.5 (1.2, 2.0) | 785 | 278 | 288 | 129 | 1035 | 301 |
| Null (-) | 1.0 (ref.) | 2.1 (1.4, 3.2) | 1.0 (ref.) | 2.4 (1.4, 4.0) | 194 | 87 | 71 | 38 | 300 | 67 |
| P-interaction§ | 0.03 | 0.18 | ||||||||
| NAT2 genotype | ||||||||||
| Rapid/intermediate acetylator | 1.0 (ref.) | 1.5 (1.1, 2.0) | 1.0 (ref.) | 1.9 (1.2, 2.8) | 330 | 128 | 123 | 57 | 459 | 113 |
| Slow acetylator | 1.0 (ref.) | 1.4 (1.1, 1.8) | 1.0 (ref.) | 1.6 (1.2, 2.1) | 552 | 217 | 204 | 96 | 819 | 233 |
| P-interaction§ | 0.60 | 0.58 | ||||||||
| GSTM1/GSTT1 genotype‡ | ||||||||||
| GSTM1+, GSTT1 + | 1.0 (ref.) | 1.4 (1.0, 1.8) | 1.0 (ref.) | 1.7 (1.2, 2.5) | 378 | 142 | 136 | 68 | 479 | 140 |
| GSTM1-, GSTT1+ | 1.0 (ref.) | 1.2 (0.9, 1.5) | 1.0 (ref.) | 1.4 (0.9, 1.9) | 400 | 135 | 151 | 60 | 541 | 154 |
| GSTM1+, GSTT1- | 1.0 (ref.) | 2.8 (1.6, 5.0) | 1.0 (ref.) | 4.8 (2.1, 11) | 98 | 47 | 34 | 22 | 158 | 24 |
| GSTM1-, GSTT1- | 1.0 (ref.) | 1.6 (0.9, 2.9) | 1.0 (ref.) | 1.4 (0.6, 3.1) | 94 | 40 | 36 | 16 | 138 | 41 |
| P-interaction§ | 0.03 | 0.09 | ||||||||
NECC: unconditional logistic regression adjusted for age, study center, duration of oral contraceptive use (months), parity (continuous), tubal ligation, body mass index (kg/m2, continuous), and duration of postmenopausal hormone use (months); NHS: unconditional logistic regression adjusted for age in months, menopausal status at diagnosis (post, pre/dubious), DNA source, duration of oral contraceptive use (months), parity (continuous), tubal ligation, body mass index (kg/m2, continuous), and duration of postmenopausal hormone use (months)
P-values for tests for heterogeneity comparing the NECC and NHS results were all >0.36
NHS analysis adjusted for age, menopausal status at diagnosis, and DNA source only, to improve stability of estimates
P-values for interaction based on likelihood ratio test comparing unconditional logistic regression models with and without gene-talc interaction terms