Prognostic markers in triple‐negative breast cancer

Abstract

Basic helix–loop–helix (bHLH) transcription factors play important roles in cell type specification and differentiation during the development of the nervous system. In this study, we identified a chicken homolog of Atonal 8/ath6 (Cath6) and examined its role in the developing retina. Unlike other Atonal‐family proneural genes that induce neuronal differentiation, Cath6 was expressed in stem cell‐like progenitor cells in the marginal region of the retina, and its overexpression inhibited neuronal differentiation. A Cath6 fused with a VP16 transactivation domain recapitulated the inhibitory effect of Cath6 on neuronal differentiation, indicating that Cath6 functions as a transcription activator. These results demonstrate that Cath6 constitutes a unique member of the Atonal‐family of genes in that it acts as a negative regulator of neuronal differentiation. Developmental Dynamics 239:2492–2500, 2010. © 2010 Wiley‐Liss, Inc.

Comparison of basal-like triple-negative breast cancer defined by morphology, immunohistochemistry and transcriptional profiles

“…Some series have suggested that, in lymph node-negative breast cancer in Definitions of basal-like breast cancer particular, the basal phenotype is of independent prognostic value, whereas ER/PR expression is not prognostically significant. 17 Clearly, accurate determination of ER and HER2 status is necessary to identify clinical targets and direct therapy. The immunohistochemical assessment of basal cytokeratins and EGFR is not routine and does not form part of invasive breast cancer pathology minimum data sets.…”

“…[13][14][15] Many current studies make use of microarray-based expression profiling to define basal-like breast cancers; however, continuous efforts are being made to define these lesions with standard pathological techniques, for example, using immunohistochemical markers as surrogates. 7,16,17 With the latter approach, it has been reported that B50% of triple-negative breast cancers are either positive for epidermal growth factor receptor 1 (EGFR) and/or basal cytokeratin (CK) 5/6 and have been referred to as 'Core Basal'. 16 Among triple-negative breast cancers treated with adjuvant anthracycline-based chemotherapy, the 'Core Basal' phenotype has been reported to be associated with a significantly worse outcome.…”

Basal-like and triple-negative breast cancers: a critical review with an emphasis on the implications for pathologists and oncologists

“…10,15,53,68,69 It is true that the majority of triplenegative cancers are of basal-like phenotype 22,60,68 and the majority of tumors expressing 'basal' markers are triple-negative. 16 77,78 (tumors with androgen receptor pathway activation, although a substantial proportion of these tumors may be classified as of HER2 subtype 78 …”

“…1,15,69 Taken together, these results are in accord with the concept that the triple-negative phenotype is not an ideal surrogate marker for basal-like breast cancers. 60,70,81 Relationship between basal-like breast cancer and BRCA1 germ-line mutations There is increasing evidence to suggest a link between BRCA1 pathway and basal-like breast cancers. 82,83 The majority of tumors arising in BRCA1 germ-line mutation carriers, in particular those diagnosed before 50 years of age, have morphological features similar to those described in basal-like cancers 84,85 and show a basal-like phenotype as defined by immunohistochemistry 86,87 or expression arrays.…”

Triple-negative breast cancers express receptors for growth hormone-releasing hormone (GHRH) and respond to GHRH antagonists with growth inhibition

“…This subgroup shows distinctive clinical features and accounts for 10-17% of all breast carcinomas [1,2]. Triple-negative breast cancers tend to affect more frequently younger patients [3], are more prevalent in African Americans [4] and clinically more aggressive than tumors belonging to the other known molecular subgroups [1,2,5,6]. Although triple-negative cancers are sensitive to chemotherapy [1], the prognosis of patients with such tumors is poor.…”