Pathologic features and molecular phenotype by patient age in a large cohort of young women with breast cancer

Abstract

Prior studies have suggested a higher prevalence of high grade, ER-negative, HER2-positive, and basal-like carcinomas in young women with breast cancer. However, the precise distribution of poor prognostic features in this population remains unclear. We examined the pathologic features and distribution of molecular phenotype in relation to patient age in a large group of young women (≤40 years) with invasive breast cancer. Medical records were reviewed for clinical characteristics, tumor stage, and receptor status. Pathologic features, including those features associated with basal-like carcinomas, were examined by central review. Using tumor grade and biomarker expression, cancers were categorized as luminal A (ER+ and/or PR+ and HER2-, histologic grade 1 or 2); luminal B (ER+ and/or PR+ and HER2+, or ER and/or PR+, HER2- and grade 3); HER2 (ER and PR- and HER2+); and triple negative (ER-, PR-, and HER2-). Among 399 women of ≤40 years, 33% had luminal A tumors, 35% luminal B, 11% HER2 (ER-negative), and 21% triple negative. Compared to published results for all breast cancers, a greater proportion of young women had luminal B tumors, and a lesser proportion had luminal A. There were no significant differences in molecular phenotype, tumor stage or grade among the different age groups of young women. However, this population of young women presented with a different distribution of molecular phenotypes compared to the general population of women with breast cancer. These findings may have implications with regard to the etiology and prognosis of breast cancer in young women.

Second international consensus guidelines for breast cancer in young women (BCY2)

“…[5][6][7][8][9]16 Recent studies suggest potentially unique biology of tumors arising in younger patients. 7,[29][30][31] Whether young age alone represents an independent prognostic or predictive factor as we improve our understanding of tumor sub-typing remains an area of active research with significant clinical implications. At this time the choice of most treatments for young women, both in the early and the advanced setting, should be driven by similar factor as for older women, i.e.…”

Biology of breast cancer during pregnancy using genomic profiling

“…Breast cancer arising in young women exhibits distinct biological features and has been shown to pursue an aggressive clinical behavior (Cancello et al 2010, Azim et al 2012a, Collins et al 2012, Narod 2012. Among the unique situations that young women with breast cancer may face is pregnancy.…”

Dietary flavonoid and lignan intake and breast cancer risk according to menopause and hormone receptor status in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study

“…Differences have been observed in the aetiology, treatment and prognosis of hormone receptor status-positive and -negative BC [2,3]. Because of the importance of menopause as an effect modifier, studies should stratify for menopause status [1].…”