scholarly journals PIONEER- Pre-operative wIndOw study of letrozole plus PR agonist megestrol acetate versus letrozole aloNE in post-menopausal patients with ER-positive breast cancer

2017 ◽  
Vol 28 ◽  
pp. v65-v66
Author(s):  
S.S. Kumar ◽  
G. Dougall ◽  
A-L. Vallier ◽  
L. Jones ◽  
W. Qian ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Megestrol Acetate ◽  
Er Positive ◽  
Post Menopausal ◽  
Positive Breast Cancer

Is incomplete estradiol suppression during aromatase inhibitor treatment in post-menopausal patients with breast cancer due to insufficient systemic drug concentrations?

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 1063-1063
Author(s):  
Daniel Louis Hertz ◽  
Kelley M. Kidwell ◽  
Kelly A Speth ◽  
Christina L Gersch ◽  
Zeruesenay Desta ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Logistic Regression ◽  
Plasma Concentrations ◽  
High Plasma ◽  
Limit Of Quantification ◽  
Drug Concentrations ◽  
Menopausal Women ◽  
Er Positive ◽  
Post Menopausal ◽  
Positive Breast Cancer

1063 Background: Aromatase inhibitors (AI) suppress estrogen biosynthesis and are effective treatments for estrogen receptor (ER)-positive breast cancer. In a prospectively enrolled cohort we observed a subset of post-menopausal women who exhibit high plasma estradiol (E2) concentrations during AI treatment, which could potentially contribute to treatment failure. We tested the hypothesis that incomplete E2 suppression is due to insufficient systemic AI concentrations. Methods: Five hundred post-menopausal women with ER-positive breast cancer were randomized to daily exemestane (Exe) 25 mg or letrozole (Let) 2.5 mg. Plasma E2 was measured using GC/MS/MS (lower limit of quantification (LLOQ) = 1.25 pg/mL) at baseline and after 3 months. Let and Exe plasma concentrations measured after 1 or 3 months were compared with the magnitude of E2 depletion using four complementary statistical procedures to assess associations of drug concentrations with: 1) a binary outcome of E2 suppression below LLOQ (logistic regression), 2) 3-month E2 concentrations (linear regression), 3) absolute change from baseline in E2 concentrations (Spearman correlation), and 4) an ordinal outcome defined by E2: decreased to below LLOQ, decreased but not to LLOQ, stayed the same, or increased from baseline (cumulative logistic regression). Results: 397 patients with E2 and AI concentration measurements were evaluable (Exe n = 199, Let n = 198). Thirty (7.6%) patients (Exe n = 13, Let n = 17) had E2 concentrations above the LLOQ at 3 months (range: 1.42-63.8 pg/mL). Exe and Let concentrations were not associated with achievement of unmeasurable E2 concentrations, on-treatment E2 concentrations, E2 change from baseline, or ordinal groupings of E2 change (all p > 0.05). In a parallel analysis there was no association of estrone-sulfate and drug concentrations (data not shown). Conclusions: Our results suggest that circulating drug concentrations do not explain incomplete E2 suppression in women receiving AI therapy. Additional studies are underway to determine whether age, body mass and genetic variation in the aromatase enzyme influence AI treatment response.

Antitumor Activity and Underlying Mechanism of Phomoxanthone B in MCF7 Cells

2020 ◽  
Vol 20 ◽  
Author(s):  
Chuan Chen ◽  
Ziyue Zhao ◽  
Qian Dong ◽  
XueHui Gao ◽  
Huibin Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cell Cycle ◽  
Antitumor Activity ◽  
Oxidative Phosphorylation ◽  
Tumor Cells ◽  
Transcriptome Analysis ◽  
Mcf7 Cells ◽  
Er Positive ◽  
Induced Apoptosis ◽  
Positive Breast Cancer

Background:: Xanthones are a class of heterocyclic natural products, which are promising sources of anticancer leads. Phomoxanthone B（PXB）and Phomoxanthone A（PXA）are xanthone dimers. PXA is well studied as an anti-cancer agent, but PXB is not. In our study, PXB was isolated from the endophytic fungus Phomopsis sp. By254. Objective:: The purpose of this study was to identify the underlying anti-tumor mechanisms of PXB in breast cancer MCF7 cell line. Methods:: Apoptosis, cell cycle, proliferation, invasion and migration assays were used to assess the antitumor activity of PXB. RNA sequencing was used to analyze the effect of PXB treatment on gene expression in MCF7 cells. Results:: PXB showed cytotoxicity toward a variety of tumor cells, especially MCF7 cells. PXB inhibited the migration and invasion, arrested cell cycle at G2/M phase and induced apoptosis associated with caspase-3 activation in MCF7 cells. The detailed transcriptome analysis revealed that PXB affected several pathways related to tumorigenesis, metabolisms-, and oxidative phosphorylation in MCF7 cells. KEGG transcriptome analysis revealed that PXB upregulated pro-survival signal pathways such as MAPK, PI3K-AKT and STAT3 pathways. We found that PXB also significantly upregulated the expression of IL24, DDIT3 and XAF1, which may contribute to PXB-induced apoptosis. We further found that PXB may downregulate oxidative phosphorylation by decreasing the expression of electron transport chain genes, especially MT-ND1, which is a potential unfavorable prognostic marker for ER-positive breast cancer. Conclusion:: PXB exerts strong cytotoxicity against human tumor cells and has a potential for ER-positive breast cancer treatment.

scholarly journals Clinical CYP2D6 Genotyping to Personalize Adjuvant Tamoxifen Treatment in ER-Positive Breast Cancer Patients: Current Status of a Controversy

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 771
Author(s):  
Tessa A. M. Mulder ◽  
Mirjam de With ◽  
Marzia del Re ◽  
Romano Danesi ◽  
Ron H. J. Mathijssen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Clinical Outcome ◽  
Cancer Patients ◽  
Plasma Concentrations ◽  
Tamoxifen Treatment ◽  
Current Status ◽  
Endocrine Treatment ◽  
Breast Cancer Patients ◽  
Er Positive ◽  
Positive Breast Cancer

Tamoxifen is a major option for adjuvant endocrine treatment in estrogen receptor (ER) positive breast cancer patients. The conversion of the prodrug tamoxifen into the most active metabolite endoxifen is mainly catalyzed by the enzyme cytochrome P450 2D6 (CYP2D6). Genetic variation in the CYP2D6 gene leads to altered enzyme activity, which influences endoxifen formation and thereby potentially therapy outcome. The association between genetically compromised CYP2D6 activity and low endoxifen plasma concentrations is generally accepted, and it was shown that tamoxifen dose increments in compromised patients resulted in higher endoxifen concentrations. However, the correlation between CYP2D6 genotype and clinical outcome is still under debate. This has led to genotype-based tamoxifen dosing recommendations by the Clinical Pharmacogenetic Implementation Consortium (CPIC) in 2018, whereas in 2019, the European Society of Medical Oncology (ESMO) discouraged the use of CYP2D6 genotyping in clinical practice for tamoxifen therapy. This paper describes the latest developments on CYP2D6 genotyping in relation to endoxifen plasma concentrations and tamoxifen-related clinical outcome. Therefore, we focused on Pharmacogenetic publications from 2018 (CPIC publication) to 2021 in order to shed a light on the current status of this debate.

scholarly journals Alternative dosing of exemestane in postmenopausal women with ER-positive breast cancer. Design and methods of a randomized presurgical trial

2021 ◽  
pp. 106498
Author(s):  
Aliana Guerrieri-Gonzaga ◽  
Davide Serrano ◽  
Parjhitham Thomas ◽  
Katherine D. Crew ◽  
Nagi B. Kumar ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Postmenopausal Women ◽  
Er Positive ◽  
Design And Methods ◽  
Positive Breast Cancer
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