Increased Mortality in Women with Breast Cancer Detected during Pregnancy and Different Periods Postpartum

Abstract

Background: Because of a continued trend toward postponed childbearing, the incidence of pregnancyassociated breast cancer (PABC) is likely to increase. This study investigated the mortality in women with PABC in relation to when the tumor was detected (during pregnancy, different postpartum periods) and by time since diagnosis, compared with women with non-PABC.Methods: A population-based cohort study of 15,721 Swedish women diagnosed with breast cancer between ages 15 to 44 years, of whom 1,110 (7%) had a PABC (diagnosed during or within two years after pregnancy). Information on outcome and potential confounders was obtained from population-based health registers. Mortality rates and HRs with 95% CIs were estimated.Results: Women with PABC had higher mortality compared with women with non-PABC diagnosed at the same age and calendar period. Among women with PABC, 46% died within 15 years after diagnosis, whereas 34% died among non-PABC patients. The mortality in both groups peaked at around two years after diagnosis, with the highest peak occurring in women diagnosed 4 to 6 months after delivery (HR ¼ 3.8, 95% CI: 2.4-5.9). An increased mortality among women with PABC remained until 10 years after diagnosis.Conclusions: Women with PABC had a poorer prognosis compared with women with breast cancer and no recent birth. The mortality increase was most pronounced in the subgroup of women diagnosed shortly after delivery.Impact: An increased awareness among clinicians may help reduce the mortality in women with PABC, for example, by avoiding undue delays in diagnosis and treatment. Cancer Epidemiol Biomarkers Prev; 20(9); 1865-72. Ó2011 AACR.

Cyclooxygenase-2–dependent lymphangiogenesis promotes nodal metastasis of postpartum breast cancer

“…Further, we observed an increase in tumor-associated lymphatics in a cohort of postpartum breast cancers, which correlates with increased lymphatic vessel invasion. These results suggest that physiologically normal lymphangiogenesis that occurs in the postpartum involuting breast may facilitate breast cancer dissemination in postpartum women, an observation that may explain the increased lymph node metastasis in our postpartum patient population as well as the published increased risk for metastatic disease observed in this patient population (8)(9)(10).…”

“…In murine breast cancer models, postpartum mammary gland involution promotes mammary tumor growth, invasion, and metastasis (1,3,7). Consistent with these preclinical data, women diagnosed after childbirth and up to 5 years postpartum, cases we and others define as postpartum breast cancer (2), have increased risk for metastasis compared with age-matched nulliparous patients with similar stage disease (8)(9)(10). However the mechanism of increased metastasis in postpartum patients remains unknown.…”

Clinicopathological Features and Prognosis of Pregnancy Associated Breast Cancer – A Matched Case Control Study

“…As far as outcome of PABC is concerned data are conflicting: some authors showed no difference in outcome of PABC and non-PABC cases [14,16,24], while others consider PABC as having unfavorable prognosis [1,[7][8][9]. In a recent metaanalysis of 30 studies, Azim et al found that PABC patients had poor overall survival especially if breast cancer was diagnosed within 1 year postpartum [25].…”

“…The definition is not unanimous however, some authors define the postpartum time frame from 6 months to 2 years after delivery [1,2].…”

“…The prognosis of PABC is more often reported as being unfavorable [1,[7][8][9][10]. Whether this poor prognosis is related to pregnancy or mainly due to the young age of patientswhich in itself is known to be a poor prognostic factor [11] -is not clear.…”