Table 3.

Heterogeneity tests of the associations between risk factors and outcomes (10-year all-cause mortality and breast cancer–specific mortality), by ER status and by intrinsic-like subtype.

All-cause mortalityBreast cancer–specific mortality
ER statusIntrinsic-like subtypeeER statusIntrinsic-like subtypee
Risk factorPPPP
Age at menarche6.7E-018.6E-017.2E-011.0E+00
Age at FFTPa6.7E-011.0E+007.2E-011.0E+00
Time since last full-term birtha8.5E-011.0E+005.4E-013.3E-01
Duration of breastfeedinga7.8E-011.0E+001.0E+001.0E+00
BMI (all women)1.0E+001.0E+001.0E+001.0E+00
BMI (postmenopausal women)1.0E+001.0E+001.0E+001.0E+00
BMI (pre/perimenopausal women)1.0E+001.0E+001.0E+001.0E+00
Oral contraceptive use6.7E-016.7E-017.2E-011.0E+00
No. of pack-years of smoking6.7E-016.7E-011.0E+001.0E+00
Alcohol consumptiond1.0E+001.0E+001.0E+001.0E+00
Cumulative alcohol consumption1.0E+001.0E+001.0E+001.0E+00
Physical activityd1.0E+001.0E+001.0E+001.0E+00
  • Note: Reported P values come from a likelihood ratio test comparing a model including the ER status/subtype variable and an interaction term between such variable and a specific risk factor, with a model without the interaction term. ER negative was used as the reference category for ER status and luminal A as the reference category for the subtype variable. P values are adjusted for multiple testing using the Benjamini–Hochberg method for false discovery rate (FDR) control on 34 tests for each endpoint of interest (all-cause and breast cancer–specific mortality). All models have been stratified by study and adjusted for lymph nodes status, tumor size, tumor grade, and (neo)adjuvant systemic treatment. Age of the patients was used as time scale.

  • aAssociation estimated in parous women.

  • bFormer use of MHT was more than 6 mo before diagnosis.

  • cCurrent use of MHT was at diagnosis or within 6 mo before diagnosis.

  • dAt diagnosis or within 1 year before diagnosis.

  • eDefinition of intrinsic-like subtype follows Goldhirsch et al. 2011 as in Tables 2 and 4.