Aspirin vs Placebo as Adjuvant Therapy for Breast Cancer: The Alliance A011502 Randomized Trial.

Importance: Observational studies of survivors of breast cancer and prospective trials of aspirin for cardiovascular disease suggest improved breast cancer survival among aspirin users, but prospective studies of aspirin to prevent breast cancer recurrence are lacking. Objective: To determine whether aspirin decreases the risk of invasive cancer events among survivors of breast cancer. Design, Setting, and Participants: A011502, a phase 3, randomized, placebo-controlled, double-blind trial conducted in the United States and Canada with 3020 participants who had high-risk nonmetastatic breast cancer, enrolled participants from 534 sites from January 6, 2017, through December 4, 2020, with follow-up to March 4, 2023. Interventions: Participants were randomized (stratified for hormone receptor status [positive vs negative], body mass index [≤30 vs >30], stage II vs III, and time since diagnosis [<18 vs ≥18 months]) to receive 300 mg of aspirin (n = 1510) or placebo once daily (n = 1510) for 5 years. Main Outcomes and Measures: The primary outcome was invasive disease-free survival. Overall survival was a key secondary outcome. Results: A total of 3020 participants were randomized when the data and safety monitoring committee recommended suspending the study at the first interim analysis because the hazard ratio had crossed the prespecified futility bound. By median follow-up of 33.8 months (range, 0.1-72.6 months), 253 invasive disease-free survival events were observed (141 in the aspirin group and 112 in the placebo group), yielding a hazard ratio of 1.27 (95% CI, 0.99-1.63; P = .06). All invasive disease-free survival events, including death, invasive progression (both distant and locoregional), and new primary events, were numerically higher in the aspirin group, although the differences were not statistically significant. There was no difference in overall survival (hazard ratio, 1.19; 95% CI, 0.82-1.72). Rates of grades 3 and 4 adverse events were similar in both groups. Conclusion and Relevance: Among participants with high-risk nonmetastatic breast cancer, daily aspirin therapy did not improve risk of breast cancer recurrence or survival in early follow-up. Despite its promise and wide availability, aspirin should not be recommended as an adjuvant breast cancer treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02927249.

A Video Intervention to Improve Patient Understanding of Tumor Genomic Testing in Patients with Cancer.

Background: Tumor genomic testing (TGT) has become standard-of-care for most patients with advanced/metastatic cancer. Despite established guidelines, patient education prior to TGT is variable or frequently omitted. The purpose of this study was to evaluate the impact of a concise (3-4 minute) video for patient education prior to TGT. Methods: Based on a quality improvement cycle, an animated video was created to be applicable to any cancer type, incorporating culturally diverse images, available in English and Spanish. Patients undergoing standard-of care TGT were enrolled at a tertiary academic institution and completed validated survey instruments immediately prior to video viewing (T1) and immediately post-viewing (T2). Instruments included: 1) 10-question objective genomic knowledge/understanding; 2) 10-question video message-specific knowledge/recall; 3) 11-question Trust in Physician/Provider; 4) attitudes regarding TGT. The primary objective was change in outcomes from before to after the video was assessed with Wilcoxon signed rank test. Results: From April 2022 to May 2023, a total of 150 participants were enrolled (MBC n=53, LC n=38, OC n=59). For the primary endpoint, there was a significant increase in video message-specific knowledge (median 10 point increase; p<0.0001) with no significant change in genomic knowledge/understanding (p=0.89) or Trust in Physician/Provider (p=0.59). Results for five questions significantly improved, including the likelihood of TGT impact on treatment decision, incidental germline findings, and cost of testing. Improvement in video message-specific knowledge was consistent across demographic groups, including age, income, and education. Individuals with less educational attainment had had greater improvement from before to after video viewing. Conclusions: A concise, 3-4 minute, broadly applicable video incorporating culturally diverse images administered prior to TGT significantly improved video message-specific knowledge across all demographic groups. This resource is publicly available at http://www.tumor-testing.com, with a goal to efficiently educate and empower patients regarding TGT while addressing guidelines within the flow of clinical practice. Clinical Trial Registration: ClinicalTrials.gov NCT05215769.

Oncologists' responsibility, comfort, and knowledge managing hyperglycemia in patients with cancer undergoing chemotherapy: a cross sectional study.

PURPOSE: To assess oncologists' responsibility, comfort, and knowledge managing hyperglycemia in patients undergoing chemotherapy. METHODS: In this cross-sectional study, a questionnaire collected oncologists' perceptions about professionals responsible for managing hyperglycemia during chemotherapy; comfort (score range 12-120); and knowledge (score range 0-16). Descriptive statistics were calculated including Student t-tests and one-way ANOVA for mean score differences. Multivariable linear regression identified predictors of comfort and knowledge scores. RESULTS: Respondents (N = 229) were 67.7% men, 91.3% White and mean age 52.1 years. Oncologists perceived endocrinologists/diabetologists and primary care physicians as those responsible for managing hyperglycemia during chemotherapy, and most frequently referred to these clinicians. Reasons for referral included lack of time to manage hyperglycemia (62.4%), belief that patients would benefit from referral to an alternative provider clinician (54.1%), and not perceiving hyperglycemia management in their scope of practice (52.4%). The top-3 barriers to patient referral were long wait times for primary care (69.9%) and endocrinology (68.1%) visits, and patient's provider outside of the oncologist's institution (52.8%). The top-3 barriers to treating hyperglycemia were lack of knowledge about when to start insulin, how to adjust insulin, and what insulin type works best. Women (ß = 1.67, 95% CI: 0.16, 3.18) and oncologists in suburban areas (ß = 6.98, 95% CI: 2.53, 11.44) had higher comfort scores than their respective counterparts; oncologists working in practices with > 10 oncologists had lower comfort scores (ß = -2.75, 95% CI: -4.96, -0.53) than those in practices with ≤ 10. No significant predictors were identified for knowledge. CONCLUSION: Oncologists expected endocrinology or primary care clinicians to manage hyperglycemia during chemotherapy, but long wait times were among the top barriers cited when referring patients. New models that provide prompt and coordinated care are needed.

Alliance A011801 (compassHER2 RD): postneoadjuvant T-DM1 + tucatinib/placebo in patients with residual HER2-positive invasive breast cancer.

This report describes the rationale, purpose and design of A011801 (CompassHER2 RD), an ongoing prospective, multicenter, Phase III randomized trial. Eligible patients in the United States (US) and Canada with high-risk (defined as ER-negative and/or node-positive) HER2-positive (HER2+) residual disease (RD) after a predefined course of neoadjuvant chemotherapy and HER2-directed treatment are randomized 1:1 to adjuvant T-DM1 and placebo, versus T-DM1 and tucatinib. Patients have also received adjuvant radiotherapy and/or endocrine therapy, if indicated per standard of care guidelines. The primary objective of the trial is to determine if the invasive disease-free survival (iDFS) with T-DM1 plus tucatinib is superior to iDFS with T-DM1 plus placebo; other outcomes of interest include overall survival (OS), breast cancer-free survival (BCFS), distant recurrence-free survival (DRFS), brain metastases-free survival (BMFS) and disease-free survival (DFS). Correlative biomarker, quality of life (QoL) and pharmacokinetic (PK) end points are also evaluated.

Lay abstract In this research study (A011801; CompassHER2 RD), patients with early stage HER2-positive breast cancer who already received treatment with chemotherapy and anti-HER2 targeted therapies followed by surgery are mainly enrolled. If cancer is still present in the breast and/or lymph nodes at the time of surgery, there is a higher risk of a recurrence in the future, and enrollment on A011801 is an option. Usually, if there is tumor remaining after chemotherapy and anti-HER2 targeted therapies, the main treatment is the use of an FDA-approved intravenous drug called T-DM1. Additional treatment may also include radiotherapy and/or medications to block the activity of estrogen. The usual treatment approach reduces the likelihood of breast cancer recurring in the future. This study has been performed to answer the following question: Is the combination of T-DM1 and a newer drug tucatinib better than usual treatment with T-DM1 alone at preventing cancer from returning? Study participants will receive treatment with T-DM1 and placebo (a pill that looks like the study drug but contains no medication) or T-DM1 and tucatinib, for up to 14 cycles, unless their breast cancer returns or the side effects become too severe. Research bloods are taken on study along with standard blood work, and we also request a stored tumor sample from the original biopsy and from the breast cancer surgery for research purposes. Optional Quality of Life Questionnaires are also included in the trial. After the study, participants finish T-DM1 and placebo, or T-DM1 and tucatinib, and their doctor will continue to follow their condition with clinic visits every 6 months for 10 years and watch for side effects and for signs of breast cancer recurring. Clinical Trial Registration: NCT04457596 (ClinicalTrials.gov).

Real-World Performance of a Comprehensive Genomic Profiling Test Optimized for Small Tumor Samples.

PURPOSE: Tissue-based comprehensive genomic profiling (CGP) is increasingly used for treatment selection in patients with advanced cancer; however, tissue availability may limit widespread implementation. Here, we established real-world CGP tissue availability and assessed CGP performance on consecutively received samples. MATERIALS AND METHODS: We conducted a post hoc, nonprespecified analysis of 32,048 consecutive tumor tissue samples received for StrataNGS, a multiplex polymerase chain reaction (PCR)-based comprehensive genomic profiling (PCR-CGP) test, as part of an ongoing observational trial (NCT03061305). Sample characteristics and PCR-CGP performance were assessed across all tested samples, including exception samples not meeting minimum input quality control (QC) requirements (< 20% tumor content [TC], < 2 mm2 tumor surface area [TSA], DNA or RNA yield < 1 ng/µL, or specimen age > 5 years). Tests reporting ≥ 1 prioritized alteration or meeting TC and sequencing QC were considered successful. For prostate carcinoma and lung adenocarcinoma, tests reporting ≥ 1 actionable or informative alteration or meeting TC and sequencing QC were considered actionable. RESULTS: Among 31,165 (97.2%) samples where PCR-CGP was attempted, 10.7% had < 20% TC and 59.2% were small (< 25 mm2 tumor surface area). Of 31,101 samples evaluable for input requirements, 8,089 (26.0%) were exceptions not meeting requirements. However, 94.2% of the 31,101 tested samples were successfully reported, including 80.5% of exception samples. Positive predictive value of PCR-CGP for ERBB2 amplification in exceptions and/or sequencing QC-failure breast cancer samples was 96.7%. Importantly, 84.0% of tested prostate carcinomas and 87.9% of lung adenocarcinomas yielded results informing treatment selection. CONCLUSION: Most real-world tissue samples from patients with advanced cancer desiring CGP are limited, requiring optimized CGP approaches to produce meaningful results. An optimized PCR-CGP test, coupled with an inclusive exception testing policy, delivered reportable results for > 94% of samples, potentially expanding the proportion of CGP-testable patients and impact of biomarker-guided therapies.

Phase II study of durvalumab plus tremelimumab as therapy for patients with previously treated anti-PD-1/PD-L1 resistant stage IV squamous cell lung cancer (Lung-MAP substudy S1400F, NCT03373760).

INTRODUCTION: S1400F is a non-match substudy of Lung Cancer Master Protocol (Lung-MAP) evaluating the immunotherapy combination of durvalumab and tremelimumab to overcome resistance to anti-programmed death ligand 1 (PD-(L)1) therapy in patients with advanced squamous lung carcinoma (sq non-small-cell lung cancer (NSCLC)). METHODS: Patients with previously treated sqNSCLC with disease progression after anti-PD-(L)1 monotherapy, who did not qualify for any active molecularly targeted Lung-MAP substudies, were eligible. Patients received tremelimumab 75 mg plus durvalumab 1500 mg once every 28 days for four cycles then durvalumab alone every 28 days until disease progression. The primary endpoint was the objective response rate (RECIST V.1.1). Primary and acquired resistance cohorts, defined as disease progression within 24 weeks versus ≥24 weeks of starting prior anti-PD-(L)1 therapy, were analyzed separately and an interim analysis for futility was planned after 20 patients in each cohort were evaluable for response. RESULTS: A total of 58 eligible patients received drug, 28 with primary resistance and 30 with acquired resistance to anti-PD-(L)1 monotherapy. Grade ≥3 adverse events at least possibly related to treatment were seen in 20 (34%) patients. The response rate in the primary resistance cohort was 7% (95% CI 0% to 17%), with one complete and one partial response. No responses were seen in the acquired resistance cohort. In the primary and resistance cohorts the median progression-free survival was 2.0 months (95% CI 1.6 to 3.0) and 2.1 months (95% CI 1.6 to 3.2), respectively, and overall survival was 7.7 months (95% CI 4.0 to 12.0) and 7.6 months (95% CI 5.3 to 10.2), respectively. CONCLUSION: Durvalumab plus tremelimumab had minimal activity in patients with advanced sqNSCLC progressing on prior anti-PD-1 therapy.Trial registration numberNCT03373760.

Chemotherapy and Targeted Therapy for Patients With Human Epidermal Growth Factor Receptor 2-Negative Metastatic Breast Cancer That is Either Endocrine-Pretreated or Hormone Receptor-Negative: ASCO Guideline Update.

PURPOSE: This guideline updates recommendations of the ASCO guideline on chemotherapy and targeted therapy for patients with human epidermal growth factor receptor 2-negative metastatic breast cancer (MBC) that is either endocrine-pretreated or hormone receptor (HR)-negative. METHODS: An Expert Panel conducted a targeted systematic literature review guided by a signals approach to identify new, potentially practice-changing data that might translate into revised guideline recommendations. RESULTS: The Expert Panel reviewed abstracts from the literature review and retained 14 articles. RECOMMENDATIONS: Patients with triple-negative, programmed cell death ligand-1-positive MBC may be offered the addition of immune checkpoint inhibitor to chemotherapy as first-line therapy. Patients with triple-negative, programmed cell death ligand-1-negative MBC should be offered single-agent chemotherapy rather than combination chemotherapy as first-line treatment, although combination regimens may be offered for life-threatening disease. Patients with triple-negative MBC who have received at least two prior therapies for MBC should be offered treatment with sacituzumab govitecan. Patients with triple-negative MBC with germline BRCA mutations previously treated with chemotherapy may be offered a poly (ADP-ribose) polymerase inhibitor rather than chemotherapy. Patients with HR-positive human epidermal growth factor receptor 2-negative MBC for whom chemotherapy is being considered should be offered single-agent chemotherapy rather than combination chemotherapy, although combination regimens may be offered for highly symptomatic or life-threatening disease. Patients with HR-positive MBC with disease progression on an endocrine agent may be offered treatment with either endocrine therapy with or without targeted therapy or single-agent chemotherapy. Patients with HR-positive MBC with germline BRCA mutations no longer benefiting from endocrine therapy may be offered a poly (ADP-ribose) polymerase inhibitor rather than chemotherapy. No recommendation regarding when a patient's care should be transitioned to hospice or best supportive care alone is possible.Additional information is available at www.asco.org/breast-cancer-guidelines.

Comprehensive assessment of cytochromes P450 and transporter genetics with endoxifen concentration during tamoxifen treatment.

OBJECTIVES: Tamoxifen bioactivation to endoxifen is mediated primarily by CYP2D6; however, considerable variability remains unexplained. Our aim was to perform a comprehensive assessment of the effect of genetic variation in tamoxifen-relevant enzymes and transporters on steady-state endoxifen concentrations. PATIENTS AND METHODS: Comprehensive genotyping of CYP enzymes and transporters was performed using the iPLEX ADME PGx Pro Panel in 302 tamoxifen-treated breast cancer patients. Predicted activity phenotype for 19 enzymes and transporters were analyzed for univariate association with endoxifen concentration, and then adjusted for CYP2D6 and clinical covariates. RESULTS: In univariate analysis, higher activity of CYP2C8 (regression ß=0.22, P=0.020) and CYP2C9 (ß=0.20, P=0.04), lower body weight (ß=-0.014, P<0.0001), and endoxifen measurement during winter (each ß<-0.39, P=0.002) were associated with higher endoxifen concentrations. After adjustment for the CYP2D6 diplotype, weight, and season, CYP2C9 remained significantly associated with higher concentrations (P=0.02), but only increased the overall model R by 1.3%. CONCLUSION: Our results further support a minor contribution of CYP2C9 genetic variability toward steady-state endoxifen concentrations. Integration of clinician and genetic variables into individualized tamoxifen dosing algorithms would marginally improve their accuracy and potentially enhance tamoxifen treatment outcomes.

Tamoxifen Dose Escalation in Patients With Diminished CYP2D6 Activity Normalizes Endoxifen Concentrations Without Increasing Toxicity.

BACKGROUND: Polymorphic CYP2D6 is primarily responsible for metabolic activation of tamoxifen to endoxifen. We previously reported that by increasing the 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 genotype-guided 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. RESULTS: In 353 newly enrolled patients, genotype-guided dose escalation eliminated baseline concentration differences in IM (p = .08), but not PM (p = .009), patients. Endoxifen concentrations were similar in black and white patients overall (p = .63) and within CYP2D6 phenotype groups (p > .05). In the quality-of-life analysis of 480 patients, dose escalation did not meaningfully diminish quality of life; in fact, improvements were seen in several measures including the FACT Breast Cancer subscale (p = .004) and limitations in range of motion (p < .0001) in IM patients. CONCLUSION: Differences in endoxifen concentration during treatment can be eliminated by doubling the tamoxifen dose in IM patients, without an appreciable effect on quality of life. Validation of the association between endoxifen concentration and efficacy or prospective demonstration of improved efficacy is necessary to warrant clinical uptake of this personalized treatment strategy. IMPLICATIONS FOR PRACTICE: This secondary analysis of a prospective CYP2D6 genotype-guided tamoxifen dose escalation study confirms that escalation to 40 mg/day in patients with low-activity CYP2D6 phenotypes (poor or intermediate metabolizers) increases endoxifen concentrations without any obvious increases in treatment-related toxicity. It remains unknown whether endoxifen concentration is a useful predictor of tamoxifen efficacy, and thus, there is no current role in clinical practice for CYP2D6 genotype-guided tamoxifen dose adjustment. If future studies confirm the importance of endoxifen concentrations for tamoxifen efficacy and report a target concentration, this study provides guidance for a dose-adjustment approach that could maximize efficacy while maintaining patient quality of life.

In vivo assessment of the metabolic activity of CYP2D6 diplotypes and alleles.

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.

Significance of Circulating Tumor Cells in Metastatic Triple-Negative Breast Cancer Patients within a Randomized, Phase II Trial: TBCRC 019.

PURPOSE: Circulating tumor cells (CTC) are prognostic in metastatic breast cancer (MBC). We tested whether 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 were 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-paclitaxel) with or without tigatuzumab. 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 of 52 (26.9%), and 13 of 49 (26.5%) patients who were evaluable had elevated CTC (≥5 CTC/7.5 mL whole blood) at baseline and at days 15 and 29, respectively. Patients with elevated versus 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 versus 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 versus 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.

TBCRC 019: A Phase II Trial of Nanoparticle Albumin-Bound Paclitaxel with or without the Anti-Death Receptor 5 Monoclonal Antibody Tigatuzumab in Patients with Triple-Negative Breast Cancer.

PURPOSE: Tigatuzumab (TIG), an agonistic anti-DR5 antibody, triggers apoptosis in DR5(+) human tumor cells without crosslinking. TIG has strong in vitro/in vivo activity against basal-like breast cancer cells enhanced by chemotherapy agents. This study evaluates activity of TIG and chemotherapy in patients with metastatic triple-negative breast cancer (TNBC). EXPERIMENTAL DESIGN: Randomized 2:1 phase II trial of albumin-bound paclitaxel (nab-PAC) ± TIG in patients with TNBC stratified by prior chemotherapy. Patients received nab-PAC weekly × 3 ± TIG every other week, every 28 days. Primary objective was within-arm objective response rate (ORR). Secondary objectives were safety, progression-free survival (PFS), clinical benefit, and TIG immunogenicity. Metastatic research biopsies were required. RESULTS: Among 64 patients (60 treated; TIG/nab-PAC n = 39 and nab-PAC n = 21), there were 3 complete remissions (CR), 8 partial remissions (PR; 1 almost CR), 11 stable diseases (SD), and 17 progressive diseases (PD) in the TIG/nab-PAC arm (ORR, 28%), and no CRs, 8 PRs, 4 SDs, and 9 PDs in the nab-PAC arm (ORR, 38%). There was a numerical increase in CRs and several patients had prolonged PFS (1,025+, 781, 672, 460, 334) in the TIG/nab-PAC arm. Grade 3 toxicities were 28% and 29%, respectively, with no grade 4-5. Exploratory analysis suggests an association of ROCK1 gene pathway activation with efficacy in the TIG/nab-PAC arm. CONCLUSIONS: ORR and PFS were similar in both. Preclinical activity of TIG in basal-like breast cancer and prolonged PFS in few patients in the combination arm support further investigation of anti-DR5 agents. ROCK pathway activation merits further evaluation.

Tamoxifen and CYP2D6: a contradiction of data.

Tamoxifen is an effective antiestrogen used in the treatment of hormone receptor-positive breast cancer. Bioconversion of tamoxifen to endoxifen, its most abundant active metabolite, is primarily dependent on the activity of cytochrome P450 2D6 (CYP2D6), which is highly polymorphic. Over 20 published studies have reported on the potential association between CYP2D6 polymorphism and tamoxifen treatment outcome, with highly inconsistent results. The purpose of this review is to explore differences among 17 independent studies to identify factors that may have contributed to the discrepant findings. This report discusses six putative factors that are grouped into two categories: (a) clinical management criteria: hormone receptor classification, menopausal status, and tamoxifen combination therapy; (b) pharmacologic criteria: genotyping comprehensiveness, CYP2D6 inhibitor coadministration, and tamoxifen adherence. Comparison of these factors between the positive and negative studies suggests that tamoxifen combination therapy, genotyping comprehensiveness, and CYP2D6 inhibitor coadministration may account for some of the contradictory results. Future association studies on the link between CYP2D6 genotype and tamoxifen treatment efficacy should account for combination therapy and CYP2D6 inhibition, and interrogate as many CYP2D6 alleles as possible.

Genotype-guided tamoxifen dosing increases active metabolite exposure in women with reduced CYP2D6 metabolism: a multicenter study.

PURPOSE: We examined the feasibility of using CYP2D6 genotyping to determine optimal tamoxifen dose and investigated whether the key active tamoxifen metabolite, endoxifen, could be increased by genotype-guided tamoxifen dosing in patients with intermediate CYP2D6 metabolism. PATIENTS AND METHODS: One hundred nineteen patients on tamoxifen 20 mg daily ≥ 4 months and not on any strong CYP2D6 inhibiting medications were assayed for CYP2D6 genotype and plasma tamoxifen metabolite concentrations. Patients found to be CYP2D6 extensive metabolizers (EM) remained on 20 mg and those found to be intermediate (IM) or poor (PM) metabolizers were increased to 40 mg daily. Eighty-nine evaluable patients had tamoxifen metabolite measurements repeated 4 months later. RESULTS: As expected, the median baseline endoxifen concentration was higher in EM (34.3 ng/mL) compared with either IM (18.5 ng/mL; P = .0045) or PM (4.2 ng/mL; P < .001). When the dose was increased from 20 mg to 40 mg in IM and PM patients, the endoxifen concentration rose significantly; in IM there was a median intrapatient change from baseline of +7.6 ng/mL (-0.6 to 23.9; P < .001), and in PM there was a change of +6.1 ng/mL (2.6 to 12.5; P = .020). After the dose increase, there was no longer a significant difference in endoxifen concentrations between EM and IM patients (P = .84); however, the PM endoxifen concentration was still significantly lower. CONCLUSION: 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.

Phase II study of bortezomib and pegylated liposomal doxorubicin in the treatment of metastatic breast cancer.

BACKGROUND: Based on preclinical studies and a phase I trial of the combination of bortezomib and pegylated liposomal doxorubicin (PLD), which both showed activity in breast cancer, we conducted a phase II study of this regimen in patients with metastatic breast cancer. PATIENTS AND METHODS: Patients received bortezomib 1.3 mg/m2 on days 1, 4, 8, and 11 of an every-21-day cycle, along with PLD 30 mg/m2 on day 4. The primary objective was to evaluate the response rate of this combination, while secondary objectives were to obtain further safety data about this combination, to evaluate the time to disease progression (TTP), and to evaluate response by the breast cancer subtype. RESULTS: One of 12 evaluable patients had a partial response (8%), while 3 (25%) had stable disease. At 26 months follow-up, the median overall survival was 4.3 months (95% CI, 1.2-26.2) and the median TTP was 1.3 months (95% CI, 0.8-14.0 months). The combination was well tolerated, with the most common events including low-grade nausea and vomiting, neutropenia, and neuropathy, and no cardiac toxicity was seen. Of the 7 tumors subtyped, no association was seen between intrinsic subtype or receptor status and response. CONCLUSION: The combination of PLD and bortezomib was well tolerated but has minimal activity in heavily pretreated unselected metastatic breast cancer.

Institutional profile. UNC Institute for Pharmacogenomics and Individualized Therapy: interdisciplinary research for individual care.

The Institute for Pharmacogenomics and Individualized Therapy (IPIT) at the University of North Carolina at Chapel Hill (NC, USA) is a collaborative, multidisciplinary unit that brings together faculty from different disciplines and crosses the traditional departmental/school structure to perform pharmacogenomics research. IPIT investigators work together towards the goal of developing therapies to enable the delivery of individualized medical care. The NIH-supported Comprehensive Research on Expressed Alleles in Therapeutic Evaluation (CREATE) group leads the field in the evaluation of pathways regulating drug activity, and also provides a foundation for future IPIT research. IPIT members perform bench research, clinical cohort analysis and prospective clinical intervention studies, research on the integration of pharmacogenomic therapy into practice and research to foster global health pharmacogenomics application through the Pharmacogenetics for Every Nation Initiative. IPIT Investigators are actively incorporating a pharmacogenomics curriculum into existing teaching programs at all levels.

What is triple-negative breast cancer?

Triple-negative (ER-negative, PR-negative, HER2/neu not overexpressed) breast cancer has distinct clinical and pathologic features, and is a clinical problem because of its relatively poor prognosis, aggressive behaviour and lack of targeted therapies, leaving chemotherapy as the mainstay of treatment. Most triple-negative tumours fall into the basal-like molecular subtype of breast cancer, but the terms are not completely synonymous. Among the intriguing characteristics of triple-negative breast cancer is its association with cancers arising in BRCA1 mutation carriers, in young women and in African-American women. The reasons for these associations are unclear but may ultimately provide avenues for prevention and targeted therapy. This review discusses the definitions and characteristics of as well as current and evolving therapies for triple-negative and basal-like breast cancer.