Age-related clusters and favorable immune phenotypes in breast cancer of the young

Breast cancer (BC) patients aged below 40 years at diagnosis experience aggressive disease and poorer survival compared to women diagnosed at 40-49 years, but the age-related biology is described to little extent. Here, we explored transcriptional alterations in BC to gain better understanding of age-related tumor biology. We studied a subset of the Bergen in-house cohort (n=127, age range 26-49) and used the NanoString Breast Cancer 360 expression panel on formalin-fixed paraffin-embedded breast cancer tissue, and publicly available global breast cancer mRNA expression data (n=204, age range 22-49), to explore differentially expressed genes between the young (age