Search

Recently, breast cancer (BC) continuously ranks first in the incidence rate of malignant neoplasms in women worldwide. Quadruple negative BC (QNBC) is a recently identified subtype of triple negative BC (TNBC) presenting with negative androgen receptor expression. QNBC characterization and treatment is fraught with many challenges. There is cumulative evidence suggesting that QNBC is highly proliferative and immunogenic, rendering it an ideal candidate for cytotoxic chemotherapy and immunotherapy. Several chemotherapeutic agents such as imatinib, cabozantinib, dasatinib, lucitanib, sunitinib, docetaxel, doxorubicin, and cyclophosphamide in QNBC patients are highlighted. Some subtypes and related pathway proteins are preferentially expressed in QNBC and may act as effective therapeutic targets such as acyl-CoA synthetase 4, S-phase kinase associated protein 2, immune checkpoint inhibitors, kinesin family member C1, and epidermal growth factor receptor. Several recent investigations comparing the therapeutic approach to QNBC and TNBC are briefly reviewed. Further more intensive and problem-oriented research in this topic of rising socio-medical importance is needed. [ABSTRACT FROM AUTHOR]

Quadruple-negative breast cancer (QNBC) presents with negative expression of estrogen, progesterone, and androgen receptors and of human epidermal growth factor receptor 2. This BC subtype has the worst prognosis. In QNBC, there is a greater paucity of prognostic biomarkers than in androgen receptors-positive triple negative BC (TNBC). Absent androgen receptor expression confers a more aggressive QNBC course and correlates with the expression of cancer stem cell phenotype, COX-2, and basal markers such as CK5 and nestin. Basal-like phenotype is significantly associated with adverse prognostic markers including high KI-67, COX-2 expression, and cancer stem cell phenotype. Engrailed-1 expression is associated with unfavorable overall survival in QNBC patients. Non-coding ribonucleic acids play a significant role in BC tumourigenesis by virtue of their oncogenic and tumour-suppressive properties. The identification of QNBC-specific circulating microribonucleic acids may improve tumour detection and prognosis. There is an obvious necessity to intensify the problem-oriented interdisciplinary research on the hot topic of prognostic biomarkers of QNBC. [ABSTRACT FROM AUTHOR]