Gene pathways associated with prognosis and chemotherapy sensitivity in different molecular subtypes of breast cancer

Excerpt

Breast cancer consists of multiple different molecular subtypes and different biological processes, and consequently different molecular markers are associated with prognosis and chemotherapy sensitivity in the distinct disease subsets [1]. A large number of biological processes including cell cycle regulation, DNA replication, mitotic spindle checkpoint, and p53 function are strongly prognostic in ER⁺ cancers but not among ER^- cancers [2, 3]. Interestingly, the number of biological pathways, and therefore genes, that are associated with prognosis or treatment sensitivity are substantially larger and more consistent in ER⁺ cancers than among ER^- tumors [1, 4]. This implies that it is easier to discover prognostic and predictive markers for ER⁺ than for ER^- cancers. In ER^- cancers, the single most consistent, but still modestly accurate, good prognostic predictor is the presence of immune cell infiltration [5]. Immune cell signatures are also associated with more favorable prognosis in highly proliferative ER⁺ cancers but not in ER⁺ cancers with low proliferation [6]. …