Acceptable cardiac safety profile of neoadjuvant 5-fluorouracil, epirubicin, cyclophosphamide and celecoxib (FEC-C) for breast cancer: a subanalysis of biomarkers for cardiac injury

MAGI1, a New Potential Tumor Suppressor Gene in Estrogen Receptor Positive Breast Cancer

Membrane-associated guanylate kinase (MAGUK) with inverted domain structure-1 (MAGI1) is an intracellular adaptor protein that stabilizes epithelial junctions consistent with a tumor suppressive function in several cancers of epithelial origin. Here we report, based on experimental results and human breast cancer (BC) patients’ gene expression data, that MAGI1 is highly expressed and acts as tumor suppressor in estrogen receptor (ER)⁺/HER2⁻ but not in HER2⁺ or triple negative breast cancer (TNBC). Within the ER⁺/HER2⁻ subset, high MAGI1 expression associates with ESR1 and luminal genes GATA3 and FOXA1 expression and better prognosis, while low MAGI1 levels correlates with higher histological grade, more aggressive phenotype and worse prognosis. Experimentally, MAGI1 downregulation in the ER⁺ human BC cells MCF7 impairs ER expression and signaling, promotes cell proliferation, and reduces apoptosis and epithelial differentiation. MAGI1 downregulation in the ER⁺ murine BC cell line 67NR accelerates primary tumor growth and enhances experimental lung metastasis formation. MAGI1 expression is upregulated by estrogen/ER, downregulated by prostaglandin E2/COX-2axis, and negatively correlates with inflammation in ER⁺/HER2⁻ BC patients. Taken together, we show that MAGI1 is a new potential tumor suppressor in ER⁺/HER2⁻ breast cancer with possible prognostic value for the identification of patients at high-risk of relapse within this subset.

Celecoxib in breast cancer prevention and therapy

Breast cancer has a high incidence worldwide. The results of substantial studis reveal that inflammation plays an important role in the initiation, development, and aggressiveness of many malignancies. The use of celecoxib, a novel NSAID, is repetitively associated with the reduced risk of the occurrence and progression of a number of types of cancer, particularly breast cancer. This observation is also substantiated by various meta-analyses. Clinical trials have been implemented on integration treatment of celecoxib and shown encouraging results. Celecoxib could be treated as a potential candidate for antitumor agent. There are, nonetheless, some unaddressed questions concerning the precise mechanism underlying the anticancer effect of celecoxib as well as its activity against different types of cancer. In this review, we discuss different mechanisms of anticancer effect of celecoxib as well as preclinical/clinical results signifying this beneficial effect.

High-Sensitivity Troponin T and NT-proBNP Kinetics in Breast Cancer Chemotherapy

BACKGROUND/AIMS

Doxorubicin (DOX) and trastuzumab (TRA) are associated with cardiac dysfunction.

METHOD

High-sensitivity troponin T (hs-TnT) and brain natriuretic peptide attached to the amino acid N-terminal fragment in the prohormone (NT-proBNP) were measured before and on days +1, +2, +3, and +7 during cycles 1 and 2 of therapy with DOX or TRA in breast cancer patients.

RESULTS

Five of eleven DOX-treated women, compared with 2/11 TRA-treated women, had undetectable baseline hs-TnT. By day +1 of cycle 2, all the DOX-treated women (p = 0.03) but only 7/11 TRA-treated women (p = ns) had detectible hs-TnT. Time to peak was 1-2 days for both groups. In the DOX-treated women, hs-TnT showed significant peaks from precycle baseline, increases in precycle 1 to precycle 2 levels, and a cycle 1 to cycle 2 peak and area under the curve (AUC). hs-TnT increased from precycle (1, 4.6 ± 6.3 pg/mL) to a cycle 2 peak of 16.1 ± 15.0 pg/mL (p < 0.002). No increases were seen with the TRA treatment. Transient posttreatment increases in NT-proBNP were seen after both therapies.

CONCLUSION

DOX was associated with increased pretreatment baseline, peak, and AUC hs-TnT levels. Both DOX and TRA acutely perturb NT-proBNP. Assessment of pre- and posttreatment hs-TnT could be a means of quantifying cumulative myocardial injury in the course of chemotherapy.