Breast cancer — one term, many entities?

Abstract

Breast cancer, rather than constituting a monolithic entity, comprises heterogeneous tumors with different clinical characteristics, disease courses, and responses to specific treatments. Tumor-intrinsic features, including classical histological and immunopathological classifications as well as more recently described molecular subtypes, separate breast tumors into multiple groups. Tumor-extrinsic features, including microenvironmental configuration, also have prognostic significance and further expand the list of tumor-defining variables. A better understanding of the features underlying heterogeneity, as well as of the mechanisms and consequences of their interactions, is essential to improve targeting of existing therapies and to develop novel agents addressing specific combinations of features.

Inhibition of the autocrine IL-6–JAK2–STAT3–calprotectin axis as targeted therapy for HR−/HER2+ breast cancers

“…Breast cancer is not a homogeneous malignancy but rather a heterogeneous group of tumor diseases (Bertos and Park 2011). Hyperactivation of HER2 has been classically considered one of the determinants that define ∼20% of all breast cancers, and, consequently, HER2 + breast cancers have been managed in the clinic as a homogeneous group (Hynes and Lane 2005;Lemmon and Schlessinger 2010).…”

The tumor microenvironment at a glance

“…Can the composition of the TME be modulated by oncogenic mutations? Certainly in breast cancers there is heterogeneity in both malignant and stromal gene-expression signatures (Bertos and Park, 2011). It is also still not clear whether tumors at different sites in the body have a different TME composition, but we do know that there are important differences in the TME between different cancers, both murine and human (e.g.…”

“…It is also still not clear whether tumors at different sites in the body have a different TME composition, but we do know that there are important differences in the TME between different cancers, both murine and human (e.g. Bertos and Park, 2011). In addition, an aging immune system could have a more tumor-promoting phenotype.…”

Curcumin and its derivatives in breast cancer: Current developments and potential for the treatment of drug-resistant cancers

“…Historically breast cancers have been classified by histological grade. The most common subtypes are reported as invasive ductal carcinoma not otherwise specified (IDS NOS), with 75% prevalence and invasive lobular carcinoma (ILC) with 10% prevalence [1]. With the development of rapid immunohistological screening techniques, classification by receptor status has also become common.…”

“…In general, ER+ tumours respond best to available therapeutics and have the highest survival rates whereas triple negative cancers, lacking ER, PR and HER2, remain resistant to current treatment options and have the worst prognosis [3]. Further developments in experimental techniques allow researchers to type cancers based on DNA, RNA and microRNA markers but many of these classifications are prohibitively expensive and so are not immediately relevant to the clinical setting [1,[4][5][6][7].…”