CYP2D6 genotype and adverse effects as indicators of plasma endoxifen in breast cancer patients taking tamoxifen.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 550-550
Author(s):  
Bavanthi Balakrishnar ◽  
Alexander M. Menzies ◽  
Sayed Sahanawaz Ali ◽  
Shang Heng Yeap ◽  
Bo Gao ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Adverse Effects ◽  
Cancer Patients ◽  
High Performance ◽  
Standard Dose ◽  
Therapeutic Monitoring ◽  
Cyp2d6 Genotype ◽  
Nucleotide Polymorphisms ◽  
Breast Cancer Patients ◽  
Related Factors

550 Background: Tamoxifen is a prodrug. Its principal active metabolite endoxifen is a product of cytochrome P450 2D6 (CYP2D6) metabolism. The CYP2D6 gene is highly polymorphic with a number of relatively common reduced function alleles. The aim of this study was to determine whether plasma endoxifen levels were reflected by CYP2D6 genotype or adverse effects in individuals taking tamoxifen. Methods: Plasma endoxifen was measured by High Performance Liquid Chromatography / Mass Spectroscopy in 90 breast cancer patients taking 20mg tamoxifen per day. Ten CYP2D6 single nucleotide polymorphisms were assessed to designate four putative CYP2D6 functional categories: ultra-rapid (UM), extensive (EM), intermediate (IM) and poor (PM) metabolizers. CYP2D6 inhibitor use and adverse effects were documented. The study was part of an ongoing Australian trial of tamoxifen dose escalation. Results: There was marked variation in plasma endoxifen levels across the cohort (mean 27.6 nM, SD 14.3). Endoxifen levels were significantly associated with metabolizer categories (p<0.001, r= -0.44), but were not distinctive between categories. For example, in the EM category (n=46) endoxifen levels ranged from 3.8-72.2 nM (mean 32.6 nM) with levels in the lowest quartile (3.8-19.7 nM) substantially overlapping the PM category (n=11); 6.1-24.7 nM. Consistent with an impact of non-CYP2D6 genotype related factors on endoxifen levels, endoxifen was significantly lower in 18 patients taking CYP2D6 inhibitor medications (p=0.005). There was no association between endoxifen levels and vasomotor symptoms or other adverse effects of tamoxifen. Conclusions: Endoxifen levels were highly variable in patients taking standard dose tamoxifen, and not predicted by CYP2D6 genotype or adverse effects. Therapeutic monitoring of endoxifen levels may be a useful approach to assess tamoxifen activity.

scholarly journals Non-CYP2D6 Variants Selected by a GWAS Improve the Prediction of Impaired Tamoxifen Metabolism in Patients with Breast Cancer

2019 ◽  
Vol 8 (8) ◽  
pp. 1087 ◽  
Author(s):  
Ewa E. Hennig ◽  
Magdalena Piątkowska ◽  
Krzysztof Goryca ◽  
Ewelina Pośpiech ◽  
Agnieszka Paziewska ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Genome Wide Association Study ◽  
Predictive Accuracy ◽  
Threshold Level ◽  
Cyp2d6 Genotype ◽  
Nucleotide Polymorphisms ◽  
Breast Cancer Patients ◽  
Treatment Optimization ◽  
A Genome

A certain minimum plasma concentration of (Z)-endoxifen is presumably required for breast cancer patients to benefit from tamoxifen therapy. In this study, we searched for DNA variants that could aid in the prediction of risk for insufficient (Z)-endoxifen exposure. A metabolic ratio (MR) corresponding to the (Z)-endoxifen efficacy threshold level was adopted as a cutoff value for a genome-wide association study comprised of 287 breast cancer patients. Multivariate regression was used to preselect variables exhibiting an independent impact on the MR and develop models to predict below-threshold MR values. In total, 15 single-nucleotide polymorphisms (SNPs) were significantly associated with below-threshold MR values. The strongest association was with rs8138080 (WBP2NL). Two alternative models for MR prediction were developed. The predictive accuracy of Model 1, including rs7245, rs6950784, rs1320308, and the CYP2D6 genotype, was considerably higher than that of the CYP2D6 genotype alone (AUC 0.879 vs 0.758). Model 2, which was developed using the same three SNPs as for Model 1 plus rs8138080, appeared as an interesting alternative to the full CYP2D6 genotype testing. In conclusion, the four novel SNPs, tested alone or in combination with the CYP2D6 genotype, improved the prediction of impaired tamoxifen-to-endoxifen metabolism, potentially allowing for treatment optimization.

scholarly journals Prevalence of RECQL germline variants in Pakistani early-onset and familial breast cancer patients

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Muhammad Usman Rashid ◽  
Noor Muhammad ◽  
Faiz Ali Khan ◽  
Umara Shehzad ◽  
Humaira Naeemi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Early Onset ◽  
Familial Breast Cancer ◽  
High Performance ◽  
Breast Cancer Patients ◽  
Germline Variants ◽  
Variants Of Unknown Significance ◽  
Breast Cancer Predisposition ◽  
Novel Variants

Abstract Background The RecQ Like Helicase (RECQL) gene has previously been shown to predispose to breast cancer mainly in European populations, in particular to estrogen receptor (ER) and/or progesterone receptor (PR) positive tumor. Here, we investigated the contribution of pathogenic RECQL germline variants to hereditary breast cancer in early-onset and familial breast cancer patients from Pakistan. Methods Comprehensive RECQL variant analysis was performed in 302 BRCA1 and BRCA2 negative patients with ER and/or PR positive breast tumors using denaturing high-performance liquid chromatography followed by DNA sequencing. Novel variants were classified using Sherloc guidelines. Results One novel pathogenic protein-truncating variant (p.W75*) was identified in a 37-year-old familial breast cancer patient. The pathogenic variant frequencies were 0.3% (1/302) in early-onset and familial breast cancer patients and 0.8% (1/133) in familial patients. Further, three novel variants of unknown significance, p.I141F, p.S182S, and p.C475C, were identified in familial breast cancer patients at the age of 47, 68, and 47 respectively. All variants were absent in 250 controls. Conclusions Our data suggest that the RECQL gene plays a negligible role in breast cancer predisposition in Pakistan.

Trastuzumab-Associated Cardiac Adverse Effects in the Herceptin Adjuvant Trial

2007 ◽  
Vol 25 (25) ◽  
pp. 3859-3865 ◽  
Author(s):  
Thomas M. Suter ◽  
Marion Procter ◽  
Dirk J. van Veldhuisen ◽  
Michael Muscholl ◽  
Jonas Bergh ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Adjuvant Chemotherapy ◽  
Adverse Effects ◽  
Cancer Patients ◽  
Cardiac Dysfunction ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Breast Cancer Patients ◽  
Ventricular Ejection Fraction ◽  
Neo Adjuvant Chemotherapy

Purpose The purpose of this analysis was to investigate trastuzumab-associated cardiac adverse effects in breast cancer patients after completion of (neo)adjuvant chemotherapy with or without radiotherapy. Patients and Methods The Herceptin Adjuvant (HERA) trial is a three-group, multicenter, open-label randomized trial that compared 1 or 2 years of trastuzumab given once every 3 weeks with observation in patients with HER-2–positive breast cancer. Only patients who after completion of (neo)adjuvant chemotherapy with or without radiotherapy had normal left ventricular ejection fraction (LVEF ≥ 55%) were eligible. A repeat LVEF assessment was performed in case of cardiac dysfunction. Results Data were available for 1,693 patients randomly assigned to 1 year trastuzumab and 1,693 patients randomly assigned to observation. The incidence of trastuzumab discontinuation due to cardiac disorders was low (4.3%). The incidence of cardiac end points was higher in the trastuzumab group compared with observation (severe congestive heart failure [CHF], 0.60% v 0.00%; symptomatic CHF, 2.15% v 0.12%; confirmed significant LVEF drops, 3.04% v 0.53%). Most patients with cardiac dysfunction recovered in fewer than 6 months. Patients with trastuzumab-associated cardiac dysfunction were treated with higher cumulative doses of doxorubicin (287 mg/m2 v 257 mg/m2) or epirubicin (480 mg/m2 v 422 mg/m2) and had a lower screening LVEF and a higher body mass index. Conclusion Given the clear benefit in disease-free survival, the low incidence of cardiac adverse events, and the suggestion that cardiac dysfunction might be reversible, adjuvant trastuzumab should be considered for treatment of breast cancer patients who fulfill the HERA trial eligibility criteria.

Attention to diet, exercise, and weight in the oncology clinic: Results of a national patient survey.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 10549-10549
Author(s):  
Jennifer A. Ligibel ◽  
Lori J. Pierce ◽  
Catherine M. Bender ◽  
Tracy E Crane ◽  
Christina Marie Dieli-Conwright ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Patients ◽  
Online Survey ◽  
Early Stage ◽  
Cancer Type ◽  
Breast Cancer Patients ◽  
Related Factors ◽  
Increased Risk ◽  
Diet And Exercise ◽  
To Receive

10549 Background: Obesity and related factors are increasingly associated with increased risk of developing and dying from cancer. The American Society of Clinical Oncology (ASCO) conducted a survey of cancer patients to assess their experience in receiving recommendations and referrals related to weight, diet and exercise as a part of their cancer care. Methods: An online survey was distributed to potential participants between March and June 2020 via ASCO channels and patient advocacy organizations, with an estimated reach of over 25,000 individuals. Eligibility criteria included being 18 years, living in the US, and having been diagnosed with cancer. Logistic regression was used to determine factors associated with recommendation and referral patterns. Results: In total, 2419 individuals responded to the survey. Most respondents were female (75.5%), 61.8% had an early-stage malignancy, 38.2% had advanced disease, and 49.0% were currently receiving treatment. Breast cancer was the most common cancer type (36.0%). Average BMI was 25.8 kg/m2. The majority of respondents consumed £2 servings of fruits and vegetables per day (50.9%) and exercised £2 times per week (50.4%). Exercise was addressed at most or some oncology visits in 57.5% of respondents, diet in 50.7%, and weight in 28.4%. Referrals were less common: 14.9% of respondents were referred to an exercise program, 25.6% to a dietitian and 4.5% to a weight management program. In multiple regression analyses, racial and ethnicity minority respondents were more likely to receive advice about diet (Odds Ratio [OR] 1.92, 95% CI 1.56-2.38) and weight (OR 1.64, 95% CI 1.23-2.17) compared to non-Hispanic whites, individuals diagnosed with cancer in the past 5 yrs (vs > 5 yrs) were more likely to receive advice about exercise (OR 1.48, 95% CI 1.23-1.79), and breast cancer patients were more likely to receive advice about exercise (OR 1.37, 95% CI 1.11-1.68) and weight (OR 1.46, 95% CI 1.03-2.07) than other cancer patients. Overall, 74% of survey respondents had changed their diet or exercise after cancer diagnosis. Respondents reporting that their oncologist spoke to them about increasing exercise or eating healthier foods were more likely to report a change in behavior than those whose oncologists did not (exercise: 79.6% vs 69.0%, P < 0.001; diet 81.1% vs 71.4%, P < 0.001). Respondents whose oncologist had spoken to them about exercise were more likely to exercise > 2 times per week compared to respondents whose oncologists did not address exercise (53.5% vs 44.1%, P < 0.001). Conclusions: In a national survey of oncology patients, slightly more than half of respondents reported attention to diet and exercise during oncology visits. Provider recommendations for diet and exercise were associated with positive changes in these behaviors. Additional attention to diet and exercise as part of oncology visits is needed to help support healthy lifestyle change in cancer patients.

CYP2D6 genotyping in breast cancer patients by liquid chromatography-electrospray ionization mass spectrometry

2011 ◽  
Vol 6 (3) ◽  
Author(s):  
Beate Beer ◽  
Sabine Plattner ◽  
Michael Hubalek ◽  
Anne Oberguggenberger ◽  
Monika Sztankay ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Ionization ◽  
Cancer Patients ◽  
Clinical Relevance ◽  
Cost Effective ◽  
Cyp2d6 Genotype ◽  
Breast Cancer Patients ◽  
Cyp2d6 Gene

AbstractThe application of cytochrome P450 2D6 (CYP2D6) genotyping to allow a personalized treatment approach for breast cancer patients undergoing endocrine therapy has been repeatedly discussed. However, the actual clinical relevance of the CYP2D6 genotype in the endocrine treatment of breast cancer still remains to be elucidated. A major prerequisite for the successful and valid evaluation of the CYP2D6 genotype with regard to its pharmacokinetic and clinical relevance is the availability of a comprehensive, accurate and cost-effective CYP2D6 genotyping strategy. Herein we present a CYP2D6 genotyping assay employing polymerase chain reaction (PCR)-ion pair reversed-phase high-performance liquid chromatography-electrospray ionization time-of-flight mass spectrometry (ICEMS). The genotyping strategy involves the simultaneous amplification of nine variable regions within the CYP2D6 gene by a two-step PCR protocol and the direct analysis of the generated PCR amplicons by ICEMS. The nucleotide composition profiles generated by ICEMS enable the differentiation of 37 of the 80 reported CYP2D6 alleles. The assay was applied to type the CYP2D6 gene in 199 Austrian individuals including 106 breast cancer patients undergoing tamoxifen treatment. The developed method turned out to be a highly applicable, robust and cost-effective approach, enabling an economical CYP2D6 testing for large patient cohorts.

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