Pregnancy and breast cancer: a population-based study

Abstract

The incidence of pregnancy-associated breast cancer, i.e. during pregnancy and lactation, and of pregnancy subsequent to a breast-cancer diagnosis will increase as more women choose childbearing at a later age. Few larger series are published on pregnancy-associated breast cancer. In a population-based study, we evaluated the outcome and prognostic factors in 173 breast-cancer patients. One hundred and twenty-two patients had pregnancy-associated breast cancer (20 coincident with pregnancy and 102 during lactation) and 51 patients had pregnancy subsequent to breast cancer. The median follow-up time was 151 months. Histopathological parameters and immunoreactivity for oestrogen and progesterone receptors c-erbB-2 and c-erbB-4 were studied. All three groups had tumours with high histological grade, low frequency of hormone receptors and high expression of c-erbB-2. The pregnancy and lactation groups were near identical with regard to all histopathological parameters and outcome. In the two pregnancy-associated breast-cancer groups, tumours were significantly larger, with more extensive lymph-node involvement. For node-negative tumours the respective 5- and 10-year survival rates were 62% and 50% in the pregnancy group and 60% and 50% in the lactation group. For node-positive tumours, respective 5- and 10-year survival rates were 50% and 34% in the pregnancy group and 50% and 33% in the lactation group. In the subsequent group, overall survival was high in both node-negative and -positive groups, with 5- and 10-year survival rates of 80% and 73% and 86% and 76%, respectively. Tumour size, lymph-node status, histological grade, progesterone receptor, oestrogen receptor and c-erbB-2 were significant prognostic factors in the pregnancy-associated breast-cancer patients.

Pregnancy-Associated Breast Cancer in Taiwanese Women: Potential Treatment Delay and Impact on Survival

“…HER-2/neu is synthesized in many embryonic tissues during pregnancy [34], and thus HER-2/neu over-expression was observed in 47.6% of the PABC patients, which is higher than that reported by Middleton (28%) [32], Garcia-Manero (31.6%) [12] and Halaska (33.3%) [17]. The rate of HER-2/neu oncogene over-expression in PABC patients was also higher than that among non-PABC group, which is similar to previously reported studies of 44% versus 28% of the control group [35].…”

Postpartum diagnosis demonstrates a high risk for metastasis and merits an expanded definition of pregnancy-associated breast cancer

“…Moreover, compared to non-PABC cases, various studies reported these combined pregnant and early postpartum tumors are marked by reduced estrogen and progesterone receptor positivity [1, 12, 13, 16], as well as higher frequency of Her2 neu positivity but not specifically the triple negative subtype [13, 17]. When early postpartum and pregnant cases were evaluated independently, there was contradictory data reported on the clinicopathologic features of these pregnant and postpartum subsets [12, 13, 17–20]. Moreover, a recent PABC publication concluded triple negative tumors were more likely to be diagnosed within two-years postpartum [17].…”

Risk factors for pregnancy-associated breast cancer: a report from the Nigerian Breast Cancer Study

“…With latent/preclinical time period being considered, it is likely that more breast cancer cases are pregnancy-associated (58). Recent publications suggest that PABC occurred during 5-year postpartum has worse prognosis comparing to those occurred during pregnancy (33), possibly due to mammary gland involution upon weaning (59); while another study using the one-year postpartum definition found the two groups (pregnancy vs. lactation) very similar (60). In our study, there was only one PABC case diagnosed during pregnancy and we could not examine the two groups separately.…”