Are Basal-Like and Non-Basal-Like Triple-Negative Breast Cancers Really Different?

Abstract

Objective. Triple-negative breast cancer (TNBC) accounts for 15-25% of breast cancers. It is increasingly recognized that TNBC is a motley disease. TNBC and basal-like (BL) subtype are different molecular classes of breast cancer with a high degree of overlap. However, a smaller fraction lacks the expression of basal markers in spite of being TNBC and is called non-basal-like (NBL). e aim of this study is to assess the clinicopathological features in TNBC and compare its BL and NBL subtypes. Material and Methods. A total of 200 subjects fulfilling the inclusion criteria of study were identified from the electronic medical records of institution. e tumor sections of subjects were immunohistochemically stained for basal markers, namely, 34βE12, c-Kit, and EGFR, in order to differentiate between BL and NBL subtypes. Comprehensive data were assembled from subjects' clinical records. e features of TNBC and their associations with the two subtypes were assessed using statistical analyses. Results. TNBC constituted 22% of all breast cancers. e family history of cancer was observed to be significantly associated with stage (p � 0.013). e proportions of BL and NBL subtypes were equal. Of all parameters compared between two subtypes, only lymphovascular invasion was found to have statistically significant difference (p � 0.019).ough no statistical significant difference between overall survival (OS) and disease-free survival (DFS) of two subgroups was found, BL subtype has slightly shorter DFS and OS compared to NBL. Conclusion. Both BL and NBL subtypes occur in equal proportions; hence, basalness and triple negativity are not synonyms. ough BL and NBL are prognostically similar, BL subtype shows a trend towards slightly shorter DFS and OS compared to NBL.

Varying outcomes of triple-negative breast cancer in different age groups–prognostic value of clinical features and proliferation

“…Basal-like subtype is overrepresented among young TNBC patients and characterized by BRCA mutations [52][53][54]. However, the prognostic role of basal differentiation in TNBC is not completely settled [52,55,56] and part of literature reports similar prognosis for basal and non-basal TNBC [54].…”

An Integrated Study on the Differential Expression of the FOX Gene Family in Cancer and Their Response to Chemotherapy Drugs

“…It is noteworthy that TNBC and basal-like breast cancer (BLBC) are different molecular classes of breast cancer with a high degree of overlap, and the overlap ratio of gene expression profile between TNBC and BLBC can be as high as 80% [ 61 ]. Thus, we compared and analyzed the data from Figure 5 A,I; the expression trend of FOXC1 , FOXK2 , and FOXM1 in TNBC was indeed consistent with that in BLBC.…”

Programmed death ligand-1 protein expression difference in basal like and non-basal like triple negative breast cancer and its association with disease free survival and overall survival: A systematic review

“…Many have resulted from these studies, in which one of the most highlights are PD-L1, either using IHC assay, miRNA level of CD274 gene expression. 26,29,[31][32][33] Studies in PD-L1 protein expression in TNBC and its correlation with prognosis (DFS/RFS/OS) are many, with inconsistent results. [17][18][19][20]27 This is mainly due to tumor heterogeneity, and most studies are using TMA in their studies with different reagents and methods to assess PD-L1 protein expression.…”

“…31 In future studies, PD-L1 IHC clone's choice would end up using the clone by which ICI/ Immune Checkpoint Inhibitors shows effect in clinical trials than which clone shows consistent results. [33][34][35] Recently in November 2020, the FDA granted accelerated approval of the PD-L1 inhibitor keytruda (pembrolizumab) in combination with chemotherapy to treat people with locally recurrent or metastatic TNBC. Their tumors express PD-L1.…”