This study demonstrates the feasibility of genotype-driven tamoxifen dosing and demonstrates that doubling the tamoxifen dose can increase endoxifen concentrations in IM and PM patients.
Purpose
Circulating Tumor cells (CTC) are prognostic in metastatic breast cancer (MBC). We tested whether the EpCAM based capture system (CellSearch®) is effective in patients with triple negative (TN) MBC, and whether CTC-apoptosis and clustering enhances the prognostic role of CTC.
Experimental Design
CTC enumeration and apoptosis was determined using the CXC CellSearch® kit at baseline and days 15 and 29 in blood drawn from TN MBC patients who participated in a prospective randomized phase II trial of nanoparticle albumin-bound paclitaxel (nab-PAC) with or without tigatuzumab (TIG). Association between levels of CTC and patient outcomes was assessed using logistic regression, Kaplan Meier curves, and Cox proportional hazards modeling.
Results
Nineteen of 52 (36.5%), 14/52 (26.9%), and 13/49 (26.5%) patients who were evaluable had elevated CTC (≥5CTC/7.5 ml WB) at baseline, days 15 and 29, respectively. Patients with elevated vs. not elevated CTC at each time point had worse progression free survival (PFS) (p=0.005, 0.0003, 0.0002, respectively). The odds of clinical benefit response for those who had elevated vs. low CTC at baseline and days 15 and 29 were 0.25 (95% CI: 0.08–0.84, p=0.024), 0.19 (95% CI: 0.05–0.17, p=0.014), and 0.06 (95% CI: 0.01–0.33, p=0.001), respectively. There was no apparent prognostic effect comparing CTC-apoptosis vs. non-apoptosis. Presence of CTC-cluster at day 15, and day 29 was associated with shorter PFS.
Conclusions
CTC were detected using CellSearch® assay in approximately one-third of TN MBC patients. Elevated CTC at baseline and days 15 and 29 were prognostic, and reductions in CTC levels reflected response.
Approximately 40,000 women die as a result of breast cancer each year and many more live with advanced disease. When breast cancer recurs, the goals of treatment often shift from one of cure to controlling the disease for as long as possible while palliating symptoms interfering with the patient's functional status and quality of life. This requires ongoing discussions with the patient and family about the goals of care. Many symptoms depend on the site of metastasis, with bone being the most frequent, and commonly occur with fatigue, depression, insomnia, and pain. The purpose of this paper is to identify and provide an overview of the management of the most common symptoms in patients with breast cancer metastases.
Aims
A prospectively enrolled patient cohort was used to assess whether the prediction of CYP2D6 phenotype activity from genotype data could be improved by reclassification of diplotypes or alleles.
Methods
Three hundred and fifty‐five patients receiving tamoxifen 20 mg were genotyped for CYP2D6 and tamoxifen metabolite concentrations were measured. The endoxifen : N‐desmethly‐tamoxifen metabolic ratio, as a surrogate of CYP2D6 activity, was compared across four diplotypes (EM/IM, EM/PM, IM/IM, IM/PM) that are typically collapsed into an intermediate metabolizer (IM) phenotype. The relative metabolic activity of each allele type (UM, EM, IM, and PM) and each EM and IM allele was estimated for comparison with the activity scores typically assigned, 2, 1, 0.5 and 0, respectively.
Results
Each of the four IM diplotypes have distinct CYP2D6 activity from each other and from the EM and PM phenotype groups (each P < 0.05). Setting the activity of an EM allele at 1.0, the relative activities of a UM, IM and PM allele were 0.85, 0.67 and 0.52, respectively. The activity of the EM alleles were statistically different (P < 0.0001), with the CYP2D6*2 allele (scaled activity = 0.63) closer in activity to an IM than an EM allele. The activity of the IM alleles were also statistically different (P = 0.014).
Conclusion
The current systems for translating CYP2D6 genotype into phenotype are not optimally calibrated, particularly in regards to IM diplotypes and the *2 allele. Additional research is needed to improve the prediction of CYP2D6 activity from genetic data for individualized dosing of CYP2D6 dependent drugs.
Background. Polymorphic CYP2D6 is primarily responsible for metabolic activation of tamoxifen to endoxifen. We previously reported that by increasingthe daily tamoxifen dose to 40 mg/day in CYP2D6 intermediate metabolizer (IM), but not poor metabolizer (PM), patients achieve endoxifen concentrations similar to those of extensive metabolizer patients on 20 mg/day. We expanded enrollment to assess the safety of CYP2D6 genotypeguided dose escalation and investigate concentration differences between races. Methods. PM and IM breast cancer patients currently receiving tamoxifen at 20 mg/day were enrolled for genotype-guided escalation to 40 mg/day. Endoxifen was measured at baseline and after 4 months. Quality-of-life data were collected using the Functional Assessment of Cancer Therapy-Breast (FACT-B) and Breast Cancer Prevention Trial Menopausal Symptom Scale at baseline and after 4 months.
Gentle Swedish massage applied postoperatively may have minor effects on short-term sensory pain, affective pain, and distress among women undergoing an abdominal laparotomy for removal of suspected malignant tissues.
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