Prediagnosis reproductive factors and all-cause mortality for women with breast cancer in the breast cancer family registry

Phillips KA, Milne RL, West DW, Goodwin PJ, Giles GG, Chang ET, Figueiredo JC, Friedlander ML, Keegan TH, Glendon G, Apicella C, O'Malley FP, Southey MC, Andrulis IL, John EM, Hopper JL (2009) Prediagnosis reproductive factors and all-cause mortality for women with breast cancer in the breast cancer family registry. Cancer Epidemiol Biomarkers Prev 18:1792-1797

Studies have examined the prognostic relevance of reproductive factors before breast cancer diagnosis, but most have been small and their overall findings inconclusive. Associations between reproductive risk factors and all-cause mortality after breast cancer diagnosis were assessed with the use of a population-based cohort of 3,107 women of White European ancestry with invasive breast cancer (1,130 from Melbourne and Sydney, Australia; 1,441 from Ontario, Canada; and 536 from Northern California, United States). During follow-up with a median of 8.5 years, 567 deaths occurred. At recruitment, questionnaire data were collected on oral contraceptive use, number of full-term pregnancies, age at first full-term pregnancy, time from last full-term pregnancy to breast cancer diagnosis, breastfeeding, age at menarche, and menopause and menopausal status at breast cancer diagnosis. Hazard ratios for all-cause mortality were estimated with the use of Cox proportional hazards models with and without adjustment for age at diagnosis, study center, education, and body mass index. Compared with nulliparous women, those who had a child up to 2 years, or between 2 and 5 years, before their breast cancer diagnosis were more likely to die. The unadjusted hazard ratio estimates were 2.75 [95% confidence interval (95% CI), 1.98-3.83; P < 0.001]="" and="" 2.20="" (95%="" ci,="" 1.65-2.94;="" p="">< 0.001),="" respectively,="" and="" the="" adjusted="" estimates="" were="" 2.25="" (95%="" ci,="" 1.59-3.18;="" p="">< 0.001)="" and="" 1.82="" (95%="" ci,="" 1.35-2.46;="" p="">< 0.001),="" respectively.="" when="" evaluating="" the="" prognosis="" of="" women="" recently="" diagnosed="" with="" breast="" cancer,="" the="" time="" since="" last="" full-term="" pregnancy="" should="" be="" routinely="" considered="" along="" with="" other="" established="" host="" and="" tumor="" prognostic="" factors,="" but="" consideration="" of="" other="" reproductive="" factors="" may="" not="" be="">