BackgroundWe aimed to study the pharmacokinetics and -dynamics of tamoxifen in older women with non-metastatic breast cancer.MethodsData for this analysis were derived from the CYPTAM study ... Show moreBackgroundWe aimed to study the pharmacokinetics and -dynamics of tamoxifen in older women with non-metastatic breast cancer.MethodsData for this analysis were derived from the CYPTAM study (NTR1509) database. Patients were stratified by age (age groups < 65 and 65 and older). Steady-state trough concentrations were measured of tamoxifen, N-desmethyltamoxifen, 4-hydroxy-tamoxifen, and endoxifen. CYP2D6 and CYP3A4 phenotypes were assessed for all patients by genotyping. Multiple linear regression models were used to analyze tamoxifen and endoxifen variability. Outcome data included recurrence-free survival at time of tamoxifen discontinuation (RFSt) and overall survival (OS).Results668 patients were included, 141 (21%) were 65 and older. Demographics and treatment duration were similar across age groups. Older patients had significantly higher concentrations of tamoxifen 129.4 ng/ml (SD 53.7) versus 112.2 ng/ml (SD 42.0) and endoxifen 12.1 ng/ml (SD 6.6) versus 10.7 ng/ml (SD 5.7, p all < 0.05), independently of CYP2D6 and CYP3A4 gene polymorphisms. Age independently explained 5% of the variability of tamoxifen (b = 0.95, p < 0.001, R-2 = 0.051) and 0.1% of the variability in endoxifen concentrations (b = 0.45, p = 0.12, R-2 = 0.007). Older patients had worse RFSt (5.8 versus 7.3 years, p = 0.01) and worse OS (7.8 years versus 8.7 years, p = 0.01). This was not related to differences in endoxifen concentration (HR 1.0, 95% CI 0.96-1.04, p = 0.84) or CYP polymorphisms.ConclusionSerum concentrations of tamoxifen and its demethylated metabolites are higher in older patients, independent of CYP2D6 or CYP3A4 gene polymorphisms. A higher bioavailability of tamoxifen in older patients may explain the observed differences. However, clinical relevance of these findings is limited and should not lead to a different tamoxifen dose in older patients. Show less
Lugtenberg, R.T.; Groot, S. de; Kaptein, A.A.; Fischer, M.J.; Kranenbarg, E.M.K.; Duijm-de Carpentier, M.; ... ; Dutch Breast Canc Res Grp BOOG 2020
Purpose In the phase II DIRECT study a fasting mimicking diet (FMD) improved the clinical response to neoadjuvant chemotherapy as compared to a regular diet. Quality of Life (QoL) and illness... Show morePurpose In the phase II DIRECT study a fasting mimicking diet (FMD) improved the clinical response to neoadjuvant chemotherapy as compared to a regular diet. Quality of Life (QoL) and illness perceptions regarding the possible side effects of chemotherapy and the FMD were secondary outcomes of the trial. Methods 131 patients with HER2-negative stage II/III breast cancer were recruited, of whom 129 were randomly assigned (1:1) to receive either a fasting mimicking diet (FMD) or their regular diet for 3 days prior to and the day of neoadjuvant chemotherapy. The European Organisation for Research and Treatment of Cancer (EORTC) questionnaires EORTC-QLQ-C30 and EORTC-QLQ-BR23; the Brief Illness Perception Questionnaire (BIPQ) and the Distress Thermometer were used to assess these outcomes at baseline, halfway chemotherapy, before the last cycle of chemotherapy and 6 months after surgery. Results Overall QoL and distress scores declined during treatment in both arms and returned to baseline values 6 months after surgery. However, patients' perceptions differed slightly over time. In particular, patients receiving the FMD were less concerned and had better understanding of the possible adverse effects of their treatment in comparison with patients on a regular diet. Per-protocol analyses yielded better emotional, physical, role, cognitive and social functioning scores as well as lower fatigue, nausea and insomnia symptom scores for patients adherent to the FMD in comparison with non-adherent patients and patients on their regular diet. Conclusions FMD as an adjunct to neoadjuvant chemotherapy appears to improve certain QoL and illness perception domains in patients with HER2-negative breast cancer. Trialregister ClinicalTrials.gov Identifier: NCT02126449. Show less
Purpose The diagnosis and treatment of cancer negatively affect patients' physical, functional and psychological wellbeing. Patients' needs for care cannot be addressed unless they are recognized... Show morePurpose The diagnosis and treatment of cancer negatively affect patients' physical, functional and psychological wellbeing. Patients' needs for care cannot be addressed unless they are recognized by healthcare providers (HCPs). The use of quality of life (QoL) assessments with feedback to HCPs might facilitate the identification and discussion of QoL-topics. Methods 113 patients with stage I-IIIB breast cancer treated with chemotherapy were included in this randomized controlled trial. Patients were randomly allocated to receive either usual care, or usual care with an intervention consisting of a QoL-monitor assessing QoL, distress and care needs before every chemotherapy cycle visit. Patients completed questionnaires regarding QoL, illness perceptions, self-efficacy, and satisfaction with communication. From the 2nd visit onwards, patients in the intervention arm and their HCPs received a copy of the QoL overview and results were shown in patients' medical files. Audio-recordings and patients' self-reports were used to investigate effects on communication, patient management and patient-wellbeing. A composite score for communication was calculated by summing the number of QoL-topics discussed during each consultation. Results Use of the QoL-monitor resulted in a higher communication score (0.7 topics increase per visit,p = 0.04), especially regarding the disease-specific and psychosocial issues (p < 0.01). There were no differences in patient management, QoL, illness perceptions or distress. Patients in the experimental arm (n = 60) had higher scores on satisfaction with communication (p < 0.05). Conclusions Use of a QoL-monitor during chemotherapy in patients with early breast cancer might result in a more frequent discussion of QoL-topics, associated with high levels of patients' satisfaction. Show less
Purpose Tamoxifen is part of endocrine therapy in breast cancer treatment. Studies have indicated the use of endoxifen concentrations, tamoxifen active metabolite, to guide tamoxifen efficacy.... Show morePurpose Tamoxifen is part of endocrine therapy in breast cancer treatment. Studies have indicated the use of endoxifen concentrations, tamoxifen active metabolite, to guide tamoxifen efficacy. Three endoxifen thresholds have been suggested (5.9 ng/ml, 5.2 ng/ml and 3.3 ng/ml) for therapeutic drug monitoring (TDM). Our aim was to validate these thresholds and to examine endoxifen exposure with clinical outcome in early-breast cancer patients using tamoxifen. Methods Data from 667 patients from the CYPTAM study (NTR1509) were available. Patients were stratified (above or below), according to the endoxifen threshold values for tamoxifen efficacy and tested by Cox regression. Logistic regressions to estimate the probability of relapse and tamoxifen discontinuation were performed. Results None of the thresholds showed a statistically significant difference in relapse-free survival: 5.2 ng/ml threshold: hazard ratio (HR): 2.545, 95% confidence interval (CI) 0.912-7.096,pvalue: 0.074; 3.3 ng/ml threshold: HR: 0.728; 95% CI 0.421-1.258,pvalue: 0.255. Logistic regression did not show a statistically significant association between the risk of relapse (odds ratio (OR): 0.971 (95% CI 0.923-1.021,pvalue: 0.248) and the risk for tamoxifen discontinuation (OR: 1.006 95% CI 0.961-1.053,pvalue: 0.798) with endoxifen concentrations. Conclusion Our findings do not confirm the endoxifen threshold values for TDM nor does it allow definition of a novel threshold. These findings indicate a limited value of TDM to guide tamoxifen efficacy. Show less
