[109] Caracterisation of Breast Cancer Diagnosed during Pregnancy or during the Three Years after Delivery by Tissue Array

M Antoine, B Lesieur, A Rodenas, P Callard, S Uzan, R Rouzier. TENON Hospital, Paris, France; Universit Pierre et Marie Curie, Paris, France

Background: Pregnancy associated breast cancer are defined as breast cancer occurring during pregnancy or during the year after delivery. There is a little increase of breast cancer after pregnancy during the five years after delivery. The course of these patients is more aggressive, and these tumors are frequently hormonal receptors negative and HER2 positive. We tried to define the phenotype of these tumors.
Design: 141 breast cancers diagnosed in women aged 43 or younger were retrieved from our files. Clinical course and pregnancy story was known. We analysed tissue array data from paraffin blocks for protein expression of several markers: estrogen and progesterone receptors, prolactine receptor, Her2, Ki 67, CK 5/6, CK 14, CK 18, vimentine, Ckit, EGFR, P Cadherine , E cadherine, bcl2, P53, p63, cox 2, and Muc1.
Results: During pregnancy or the 3 years after delivery, there was an increase of grade 3 tumors (p=0.05), hormonal receptor negative (p=0.009) and HER 2 positive (p=0.018) phenotype. The triple negative phenotype was also increased (p=0.07). The tissue array data confirmed the results of tumor analysis with an increase of receptor negative tumors and HER2 positive tumors. Moreover, bcl2 and prolactin receptor expression were decreased and p53, P63, and vimentin expression increased. Triple negative tumors have basal phenotype with expression of C-kit, EGFR, CK 5/6, and CK 14. RE positive tumors showed expression of Bcl2 and CK18. Non supervised hierarchical cluster analysis revealed, as previously described, 3 distinct subtypes : basal, her2 positive, and luminal.
Conclusions: Non supervised hierarchical cluster analysis showed that tumors diagnosed during 3 years after delivery are mainly of basal and HER2 positive phenotype. The presence of these phenotypes can be important as concerns systemic treatment issues.
Category: Breast

Monday, March 9, 2009 1:00 PM

Poster Session II # 51, Monday Afternoon