Prognosis of premenopausal breast cancer and childbirth prior to diagnosis

Phillips KA, Milne RL, Friedlander ML, Jenkins MA, McCredie MR, Giles GG, Hopper JL (2004) Prognosis of premenopausal breast cancer and childbirth prior to diagnosis. J Clin Oncol 22:699-705

PURPOSE: The time interval between last childbirth and subsequent breast cancer diagnosis is emerging as an important prognostic factor for premenopausal women. PATIENTS AND METHODS: We studied, prospectively, 750 women diagnosed with primary invasive breast cancer before age 45 years who participated in the population-based Australian Breast Cancer Family Study (ABCFS). RESULTS: Median follow-up time was 4.9 years (range, 0.8 to 10.8 years). Compared with nulliparous women, women who gave birth within 2 years prior to diagnosis were more likely to have axillary node-positive (58% v 41%; P =.01), and estrogen receptor-negative (58% v 39%; P =.005) tumors. The unadjusted hazard ratios for death were 2.3 (95% CI, 1.3 to 3.8; P =.002), 1.7 (95% CI, 1.1 to 2.6; P =.03), and 0.9 (95% CI, 0.6 to 1.5; P =.8) for patients who gave birth less than 2 years, 2 to 5 years, and 5 or more years before diagnosis, respectively. After adjusting for tumor characteristics, these hazard ratios were reduced to 1.9 (95%CI, 1.1 to 3.2; P =.02), 1.3 (95% CI, 0.8 to 2.1; P =.3), and 0.9 (95%CI, 0.5 to 1.4; P =.5). Modeling showed that, compared with nulliparous women, the mortality hazard ratio in parous women was 1.9, decreasing by 8% (95%CI, 4% to 13%; P <.001) for="" each="" year="" between="" last="" birth="" and="" breast="" cancer="" diagnosis.="" conclusion:="" proximity="" of="" last="" childbirth="" to="" subsequent="" breast="" cancer="" diagnosis="" is="" a="" predictor="" of="" mortality="" independent="" of="" histopathological="" tumor="" characteristics.="" clinicians="" should="" be="" aware="" that="" women="" diagnosed="" with="" breast="" cancer="" within="" a="" few="" years="" following="" childbirth="" may="" have="" a="" worse="" outcome="" than="" that="" suggested="" solely="" by="" the="" standard="" histopathological="" prognostic="" factors="" of="" their="">