Pathologic Features and Distribution of Molecular Phenotype among Young Women with Breast Cancer: Results from the Young Women's Breast Cancer Study
JD Marotti, LC Collins, S Gelber, K Ruddy, S Kereakoglow, EF Brachtel, E Winer, A Partridge. Beth Israel Deaconess Medical Center, Boston; Dana-Farber Cancer Institute, Boston; Massachusetts General Hospital, Boston
Background: Prior studies have suggested a higher prevalence of high grade, ER-negative, HER2+, and basal-like carcinomas in young women with breast cancer. However, studies are limited by small numbers and the distribution of poor prognostic features in young women remains unclear. We examined pathologic features and distribution of molecular phenotype in relation to patient age in a large group of young women with invasive breast cancer.
Design: The Young Women's Breast Cancer Study is a multi-center prospective cohort enrolling women (≤40yrs) with newly diagnosed breast cancers. Medical records were reviewed for clinical characteristics, tumor stage and receptor status. Pathologic features were examined by central review. Tumor grade and biomarker expression were used to classify cancers into molecular phenotype.
Results: The distribution of molecular phenotype and pathologic features by age group for the first 287 women reviewed is shown below. In chi-square analyses (not controlled for multiple testing), the only feature that varied significantly by age group was presence of tumor necrosis (p=0.004). There were no significant differences in molecular phenotype, tumor stage or tumor grade. Compared to published results for all breast cancers, a greater proportion of young women had luminal B (36% vs. 10-25%) tumors, and a lesser proportion had luminal A (27% vs. 60-70%).
|Clinico-pathologic Feature/Phenotype||<30 years n=31 (%)||31-35 years n=80 (%)||36-40 years n=176 (%)|
|Luminal A (ER/PR+, HER2-, low or intermediate grade)||9 (29)||22 (28)||47 (27)|
|Luminal B (ER/PR+ and HER2+ or ER/PR+, HER2- and high grade)||11 (35)||32 (40)||59 (34)|
|HER2 (ER-, PR-, HER2+)||3 (10)||11 (14)||19 (11)|
|Triple negative||8 (26)||14 (18)||41 (23)|
|Tumor grade 3||21 (68)||52 (65)||102 (58)|
|Tumor necrosis present||15 (48)||14 (18)||39 (22)|
|Prominent lymphocytic infiltrate||9 (29)||15 (19)||47 (27)|
|Pushing tumor margins||12 (39)||25 (31)||46 (26)|