Table 5.

Pooled RR (95% CI) for the association between regular talc use and ovarian cancer risk, stratified by genotype, in the NECC and the NHS

All cancers
Serous invasive cancers
Cases and controls in pooled analysis
All cases
Serous invasive
Controls
Regular talc use
Regular talc use
Regular talc
Regular talc
Regular talc
NoYesNoYesNoYesNoYesNoYes
Gene/stratum
GSTM1 genotype
    Present (+)1.0 (reference)1.6 (1.2-2.0)1.0 (reference)2.0 (1.4-2.8)48018917390646165
    Null (-)1.0 (reference)1.3 (1.0-1.6)1.0 (reference)1.4 (1.0-1.9)49817919076690198
    Pinteraction*0.130.08
GSTT1 genotype
    Present (+)1.0 (reference)1.2 (1.0-1.5)1.0 (reference)1.5 (1.2-2.0)7852782881291,035301
    Null (-)1.0 (reference)2.1 (1.4-3.2)1.0 (reference)2.4 (1.4-4.0)19487713830067
    Pinteraction*0.030.18
NAT2 genotype
    Rapid/intermediate acetylator1.0 (reference)1.5 (1.1-2.0)1.0 (reference)1.9 (1.2-2.8)33012812357459113
    Slow acetylator1.0 (reference)1.4 (1.1-1.8)1.0 (reference)1.6 (1.2-2.1)55221720496819233
    Pinteraction*0.600.58
GSTM1/GSTT1 genotype
    GSTM1+, GSTT1+1.0 (reference)1.4 (1.0-1.8)1.0 (reference)1.7 (1.2-2.5)37814213668479140
    GSTM1-, GSTT1+1.0 (reference)1.2 (0.9-1.5)1.0 (reference)1.4 (0.9-1.9)40013515160541154
    GSTM1+, GSTT1-1.0 (reference)2.8 (1.6-5.0)1.0 (reference)4.8 (2.1-11)9847342215824
    GSTM1-, GSTT1-1.0 (reference)1.6 (0.9-2.9)1.0 (reference)1.4 (0.6-3.1)9440361613841
    Pinteraction*0.030.09
  • NOTE: NECC: unconditional logistic regression adjusted for age, study center, duration of oral contraceptive use (months), parity (continuous), tubal ligation, BMI (kg/m2, continuous), and duration of PMH use (months); NHS: unconditional logistic regression adjusted for age (months), menopausal status at diagnosis (post, pre/dubious), DNA source, duration of oral contraceptive use (months), parity (continuous), tubal ligation, BMI (kg/m2, continuous), and duration of PMH use (months). P values for tests for heterogeneity comparing the NECC and NHS results were all >0.36.

  • * P values for interaction based on likelihood ratio test comparing unconditional logistic regression models with and without gene-talc interaction terms.

  • NHS analysis adjusted for age, menopausal status at diagnosis, and DNA source only to improve stability of estimates.