Cardiac Monitoring Guidelines in Clinical Trials and Post-Approval Surveillance for Patients Exposed to Anticancer Treatments: Do the Data Support the Recommendations?

Concerns regarding cardiac adverse events during and after cancer care include contractile dysfunction, dysrhythmia, and inflammation. Clinical trials and practice guidelines may require or recommend sequential ejection fraction determinations for early recognition of contractile dysfunction, bio-marker screening where inflammation or contractile dysfunction could be anticipated, and multiple electrocardiograms with timings of cardiac intervals. In some instances, surveillance schedules used in clinical trial protocols have been incorporated in recommendations without revision or critical scrutiny. When adverse events are rare and interpretative parameters imperfect, false positive results may lead to delay or interruption of vital cancer treatment, may suggest that further cardiac testing be undertaken, and may add to patient anxiety. The risks of excessive monitoring also include inconvenience and increased cost. This paper looks at areas where surveillance recommendations may be problematic, specifically, ejection fractions, cardiac biomarkers, and electrocardiographic monitoring are considered. Changes reported following surveillance monitoring of cancer patients using these parameters may reflect true adverse events or clinically relevant future risk, but interpretative uncertainty or true physiologic change that is unrelated to the drug in question should be considered. Clinicians may not be sufficiently aware of the degree to which reported changes may reflect surveillance artifacts. A balance that incorporates both the likelihood of an event that could be prevented along with clinical implications is suggested. The authors recognize that differentiating among these variables is not always possible yet advocate for modifying surveillance schedules to balance the frequency and severity of events that can be mitigated, based on reliable data. SIGNIFICANCE STATEMENT: The authors' concerns regarding the predictive value of surveillance initiatives are explored. Confounding factors and false-positive results may add to the expense of cancer care and/or compromise optimal therapeutic initiatives.

Arrhythmia in Bruton Tyrosine Kinase Inhibitor-Treated Patients: Unanswered Questions.

(No abstract allowed for commentary).

Long-term cardiac outcomes of patients with HER2-positive breast cancer treated in the adjuvant lapatinib and/or trastuzumab Treatment Optimization Trial.

BACKGROUND: Cardiotoxicity is the most significant adverse event associated with trastuzumab (T), the main component of HER2-positive breast cancer (BC) treatment. Less is known about the cardiotoxicity of dual HER2 blockade with T plus lapatinib (L), although this regimen is used in the metastatic setting. METHODS: This is a sub-analysis of the ALTTO trial comparing adjuvant treatment options for patients with early HER2-positive BC. Patients randomised to either T or concomitant T + L were eligible. Cardiac events (CEs) rates were compared according to treatment arm. RESULTS: With 6.9 years of median follow-up (FU) and 4190 patients, CE were observed in 363 (8.6%): 166 (7.9%) of patient in T + L arm vs. 197 (9.3%) in T arm (OR = 0.85 [95% CI, 0.68-1.05]). During anti-HER2 treatment 270 CE (6.4%) occurred while 93 (2.2%) were during FU (median time to onset = 6.6 months [IQR = 3.4-11.7]). While 265 CEs were asymptomatic (73%), 94 were symptomatic (26%) and four were cardiac deaths (1%). Recovery was observed in 301 cases (83.8%). Identified cardiac risk factors were: baseline LVEF < 55% (vs > 64%, OR 3.1 [95% CI 1.54-6.25]), diabetes mellitus (OR 1.85 [95% CI 1.25-2.75]), BMI > 30 kg/m2 (vs < 25 mg/kg2, OR 2.21 [95% CI 1.40-3.49]), cumulative dose of doxorubicin ≥240 mg/m2 (OR 1.36 [95% CI 1.01-1.82]) and of epirubicin≥ 480 mg/m2 (OR 2.33 [95% CI 1.55-3.51]). CONCLUSIONS: Dual HER2 blockade with T + L is a safe regimen from a cardiac perspective, but cardiac-focused history for proper patient selection is crucial. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT00490139 (registration date: 22/06/2007); EudraCT Number: 2006-000562-36 (registration date: 04/05/2007); Sponsor Protocol Number: BIG2-06 /EGF106708/N063D.

Incidence of and risk factors for major haemorrhage in patients treated with ibrutinib: An integrated analysis.

Ibrutinib, a Bruton tyrosine kinase inhibitor, is approved for treatment of various B-cell malignancies. In ibrutinib clinical studies, low-grade haemorrhage was common, whereas major haemorrhage (MH) was infrequent. We analysed the incidence of and risk factors for MH from 15 ibrutinib clinical studies (N = 1768), including 4 randomised controlled trials (RCTs). Rates of any-grade bleeding were similar for single-agent ibrutinib and ibrutinib combinations (39% and 40%). Low-grade bleeding was more common in ibrutinib-treated than comparator-treated patients (35% and 15%), and early low-grade bleeding was not associated with MH. The proportion of MH in RCTs was higher with ibrutinib than comparators (4.4% vs. 2.8%), but after adjusting for longer exposure with ibrutinib (median 13 months vs. 6 months), the incidence of MH was similar (3.2 vs. 3.1 per 1000 person-months). MH led to treatment discontinuation in 1% of all ibrutinib-treated patients. Use of anticoagulants and/or antiplatelets (AC/AP) during the study was common (~50% of patients) and had an increased exposure-adjusted relative risk for MH in both the total ibrutinib-treated population (1.9; 95% confidence interval, 1.2-3.0) and RCT comparator-treated patients (2.4; 95% confidence interval, 1.0-5.6), indicating that ibrutinib may not alter the effect of AC/AP on the risk of MH in B-cell malignancies.

Cardiac biomarkers for early detection and prediction of trastuzumab and/or lapatinib-induced cardiotoxicity in patients with HER2-positive early-stage breast cancer: a NeoALTTO sub-study (BIG 1-06).

BACKGROUND: Biomarkers of cardiac damages, such as troponin T (TnT) and the amino-terminal fragment of brain natriuretic peptide (NT-proBNP), may be useful as early predictors of cardiac dysfunction. The role of these biomarkers in patients receiving lapatinib and/or trastuzumab before anthracyclines is unknown. This study explores TnT and NT-proBNP as predictors of early cardiac toxicity in neoadjuvant breast cancer patients. METHODS: This sub-study of the NEOALTTO trial tested if changes in the levels of TnT and NT-proBNP occurred after 2 weeks of anti-HER2 therapy (lapatinib, trastuzumab or their combination) alone and/or after 18 weeks of anti-HER2 therapy plus weekly paclitaxel. RESULTS: 173 and 172 were tested at all three timepoints for NT-proBNP and TnT, respectively. The incidence of biomarker elevation was overall low at all timepoints for all the three treatment arms. A total of 13 CEs in 11 patients occurred. Biomarker elevations in patients with CEs were very rare; only one patient with subsequent CE had a NT-proBNP elevation at baseline and at week 2. CONCLUSION: These results suggest that TnT and proBNP may not be useful as early predictors of cardiac toxicity in anthracycline-naïve patients receiving trastuzumab and/or lapatinib.

False Positive Cardiotoxicity Events in Cancer-Related Clinical Trials: Risks Related to Imperfect Noninvasive Parameters.

PURPOSE: Cardiac ultrasound provides important structural and functional information that makes identification of cardiac abnormalities possible. Left ventricular ejection fraction (LVEF) provides the most commonly used parameter for recognition of treatment-related cardiac dysfunction. Random reading variance and physiologic factors influence LVEF and make the reported value imperfect. We attempt to quantitate the likelihood of false positive events by computer simulation. METHODS: We simulated four visits on hypothetical trials. We assumed a baseline LVEF of 55% and normal distribution with regard to reading error and physiologic variation. 1,000 trials of sample size 1,500 were simulated. In a separate simulation, 1,000 patients entered with LVEFs of 45, 43, and 41% to estimate true positive incidence. RESULTS: At each examination, less than 1.0% of false positives were noted. The cumulative false positive rate over four visits was 3.60%. True cardiotoxicity identification is satisfactory only when LVEF declines substantially. CONCLUSION: A 3.60% false positive rate in trials where the expected level of toxicity is low suggests that false positives are troubling and may exceed true positive results. Strategies to reduce the number of false positive results include making confirmatory studies mandatory. Evaluating increases along with decreases obtains some estimation of variance.

Cardio-oncology: an ongoing evolution.

Cancer survivorship has been greatly impacted with the development of modern cancer treatments. While significant strides have been made in managing many types of cancer, now physicians face new challenges. Over the past decades, cardiovascular events in cancer survivors have increased in prevalence, driving the development of multidisciplinary cardio-oncology programs. Additionally, as cancer patients live longer, their risk of developing secondary cardiovascular events increases. The rapid development of novel cancer therapies will continue to generate questions of cardiac risk and cardiac protection in cancer patients over time. We wish to outline the development of cardio-oncology in its present state, and provide future perspectives for the discipline.

Evaluation of a novel blood pressure scoring method and its association with clinical response in cancer patients treated with anti-vascular endothelial growth factor therapy.

BACKGROUND: The purposes of this study were to establish a novel blood pressure (BP) scoring method and to correlate it with clinical response in advanced cancer patients treated with anti-vascular endothelial growth factor (VEGF) therapies. METHODS: We retrospectively analyzed data for 368 patients from 23 clinical trials that included at least one anti-VEGF agent. We determined BP scores using the traditional Common Terminology Criteria for Adverse Events (CTCAE) version 4.0 and our novel method that considers both BP readings and number of anti-hypertensive medications the patient received. BP scores were categorized at baseline and four months. Logistic regression analysis correlated elevated scores with clinical response. Agreement between the CTCAE and the new method was assessed. RESULTS: Under the new BP scoring method, partial response rates were 20 % in patients with an elevated score at four months versus 6 % in patients without elevated score (P < 0.001). When adjusted for tumor type, age, sex, history of anti-VEGF treatment, and number of anti-VEGF treatments, elevated BP under the new scoring method had an odds ratio of 3.8 (95 % confidence interval [CI]: 1.8, 8.2; P < 0.001). The kappa statistic for agreement between the CTCAE and new scoring methods was 0.57 (95 % CI: 0.47, 0.67; P < 0.001), indicating significant concordance. CONCLUSION: Using the novel scoring method, an increase in BP scores was a marker for favorable clinical response in patients who received anti-VEGF treatment. This new method ultimately provides information with regard to clinical tumor response over and above that provided by the CTCAE scoring method.

Cancer drugs and the heart: importance and management.

Progress in the detection and treatment of cancer has led to an impressive reduction in both mortality and morbidity. Due to their mechanism of action, however, conventional chemotherapeutics and some of the newer anti-cancer signaling inhibitors carry a substantial risk of cardiovascular side effects that include cardiac dysfunction and heart failure, arterial hypertension, vasospastic and thromboembolic ischaemia, dysrhythmia, and QT prolongation. While some of these side effects are irreversible and cause progressive cardiovascular disease, others induce only temporary dysfunction with no apparent long-term sequelae for the patient. The challenge for the cardiovascular specialist is to balance the need for life-saving cancer treatment with the assessment of risk from cancer drug-associated cardiovascular side effects to prevent long-term damage. This review discusses concepts for timely diagnosis, intervention, and surveillance of cancer patients undergoing treatment, and provides approaches to clinical uncertainties.

Fluorouracil, epirubicin, and cyclophosphamide (FEC-75) followed by paclitaxel plus trastuzumab versus paclitaxel plus trastuzumab followed by FEC-75 plus trastuzumab as neoadjuvant treatment for patients with HER2-positive breast cancer (Z1041): a randomised, controlled, phase 3 trial.

BACKGROUND: Neoadjuvant chemotherapy with trastuzumab for patients with HER2-positive breast cancer can produce a pathological complete response in the breast in 30-65% of patients. We investigated the effect of the timing of trastuzumab administration with anthracycline and taxane neoadjuvant chemotherapy. METHODS: This randomised trial was done at 36 centres in the USA and Puerto Rico. Women with operable HER2-positive invasive breast cancer were randomly assigned (1:1) with a biased coin minimisation algorithm, stratified for age, tumour size, and hormone receptor status. Neither patients nor investigators (except for a cardiac safety review panel) were masked to treatment assignment. Patients randomly assigned to sequential treatment received fluorouracil 500 mg/m(2), epirubicin 75 mg/m(2), and cyclophosphamide 500 mg/m(2) (FEC-75) on day 1 of a 21-day cycle for four cycles followed by paclitaxel 80 mg/m(2) and trastuzumab 2 mg/kg (after a 4 mg/kg loading dose) once per week for 12 weeks, while those randomly assigned to the concurrent treatment group received paclitaxel and trastuzumab once per week for 12 weeks followed by four cycles of FEC-75 (on day 1 of each 21-day cycle) and once-weekly trastuzumab, in the same doses as the sequential group. Surgery, including evaluation of the axilla, was done within 6 weeks of completion of neoadjuvant treatment. The primary outcome was the percentage of patients who had a pathological complete response in the intention-to-treat population. The study is registered with ClinicalTrials.gov, number NCT00513292. FINDINGS: From Sept 15, 2007, to Dec 15, 2011, 282 women were enrolled (140 in the sequential group, 142 in the concurrent group). Two patients in the sequential group withdrew consent before starting treatment. 78 of 138 (56·5%, 95% CI 47·8-64·9) patients who received sequential treatment had a pathological complete response in the breast versus 77 of 142 (54·2%, 95% CI 45·7-62·6) who received concurrent treatment (difference 2·3%, 95% CI -9·3 to 13·9). No treatment-related deaths occurred. The most common severe toxic effects were neutropenia (35 [25·3%] of 138 patients in the sequential group vs 45 [31·7%] of 142 patients in the concurrent group) and fatigue (six [4·3%] vs 12 [8·5%]). Left ventricular ejection fraction dropped below the institutional lower limit of normal at week 12 in one (0·8%) of 130 patients who received sequential treatment and four (2·9%) of 137 patients who received concurrent treatment; by week 24, it had dropped below this limit in nine (7·1%) of 126 patients and in six (4·6%) of 130 patients, respectively. INTERPRETATION: Concurrent administration of trastuzumab with anthracyclines offers no additional benefit and is not warranted. FUNDING: US National Cancer Institute.

Cardiac tolerability of pertuzumab plus trastuzumab plus docetaxel in patients with HER2-positive metastatic breast cancer in CLEOPATRA: a randomized, double-blind, placebo-controlled phase III study.

INTRODUCTION: We report cardiac tolerability of pertuzumab plus trastuzumab plus docetaxel versus placebo plus trastuzumab plus docetaxel observed in the phase III study CLEOPATRA in patients with HER2-positive first-line metastatic breast cancer (MBC). PATIENTS AND METHODS: Left ventricular ejection fraction (LVEF) ≥ 50% and ECOG performance status of 0 or 1 were required for study entry. During the study, LVEF assessments took place every 9 weeks. Pertuzumab/placebo was given at 840 mg, then 420 mg q3w; trastuzumab was administered at 8 mg/kg, then 6 mg/kg q3w, and docetaxel was initiated at 75 mg/m(2) q3w. RESULTS: The incidence of cardiac adverse events (all grades) was 16.4% in the placebo arm and 14.5% in the pertuzumab arm, with left ventricular systolic dysfunction (LVSD, all grades) being the most frequently reported event (8.3% versus 4.4% in the placebo and pertuzumab arm). Declines in LVEF by ≥ 10% points from baseline and to <50% were reported in 6.6% and 3.8% of patients in the placebo and pertuzumab arm, respectively. Seventy-two percent (placebo arm) and 86.7% (pertuzumab arm) of those patients recovered to a value ≥ 50%. The incidence of symptomatic LVSD was low, occurring in 1.8% (n = 7) versus 1.0% (n = 4) of patients in the placebo and pertuzumab arm. In 8/11 patients, the symptomatic LVSD had resolved at data cutoff. CONCLUSION: The combination of pertuzumab plus trastuzumab plus docetaxel did not increase the incidence of cardiac adverse events, including LVSD, compared with the control arm in HER2-positive MBC. The majority of cardiac adverse events were reversible.

Cardiovascular adverse events in oncology trials: understanding and appreciating the differences between clinical trial data and real-world reports.

Reports of cardiac adverse events from oncology clinical trials often are at variance with reports derived from clinical observations or data-base reviews. These differences may lead to confusion, as different levels of risks abound in the literature, and the true cardiac risk of using some agents is uncertain. Additionally, such discrepancies may lead to the creation of over-cautious surveillance algorithms. Reasons for these reported differences are complex and often reflect subtleties in the criteria for individual patient evaluation. Both clinical trial data and real-world data have potential flaws that make reconciliation problematic. Importantly, however, both provide crucial information regarding the risk of adverse events. Major factors contribute to these differences including different tools used to diagnose events, and how those tools are interpreted. Additionally, differences in the populations of clinical trial participants and real-world populations play a crucial role. This paper looks at these differences and provides a perspective intended to help clinicians interpret reported variations in event rates derived from highly scrutinized clinical trials and broader real-world data.

BERENICE Final Analysis: Cardiac Safety Study of Neoadjuvant Pertuzumab, Trastuzumab, and Chemotherapy Followed by Adjuvant Pertuzumab and Trastuzumab in HER2-Positive Early Breast Cancer.

BERENICE (NCT02132949) assessed the cardiac safety of the neoadjuvant−adjuvant pertuzumab−trastuzumab-based therapy for high-risk, HER2-positive early breast cancer (EBC). We describe key secondary objectives at final analysis. Eligible patients received dose-dense doxorubicin and cyclophosphamide q2w × 4 ➝ paclitaxel qw × 12 (Cohort A) or 5-fluorouracil, epirubicin, cyclophosphamide q3w × 4 ➝ docetaxel q3w × 4 (B) as per physician's choice. Pertuzumab−trastuzumab (q3w) was initiated from the taxane start and continued post-surgery to complete 1 year. Median follow-up: 64.5 months. There were no new cardiac issues and a low incidence of Class III/IV heart failure (Cohort B only: one patient (0.5%) in the adjuvant and treatment-free follow-up (TFFU) periods). Fourteen patients (7.7%) had LVEF declines of ≥10% points from baseline to <50% in Cohort A, as did 20 (10.5%) in B during the adjuvant period (12 (6.2%) in A and 7 (3.6%) in B during TFFU). The five-year event-free survival rates in Cohorts A and B were 90.8% (95% CI: 86.5, 95.2) and 89.2% (84.8, 93.6), respectively. The five-year overall survival rates were 96.1% (95% CI: 93.3, 98.9) and 93.8% (90.3, 97.2), respectively. The final analysis of BERENICE further supports pertuzumab−trastuzumab-based therapies as standard of care for high-risk, HER2-positive EBC.

Developing a transfer center in a tertiary cancer center: streamlining access and communication to accommodate increasing demand for service.

Hospital-to-hospital transfers in a tertiary cancer center present an unusual set of problems involving a diverse group of acutely ill patients with highly specialized needs. The level and urgency of care required and the costs of providing optimal management often are exceedingly high. We present the administrative issues involved during a major revamping and streamlining of the Transfer Center at The University of Texas MD Anderson Cancer Center. The impetus for change included overuse of the emergency facility as a triage center for transferred patients, lack of adequate preadmission medical and financial screening of patients in anticipation of a transfer, a suboptimal level of physician-to-physician handoff communication, and insufficient protocols for prioritizing potential admissions and thus optimizing the institution's limited resources. During implementation of these revised policies, additional concerns were identified, including reluctance to modify established protocols and an inability to ensure the arrival of non-emergent transfer patients at our institution during daytime hours. Prioritizing admissions based on the degree of urgency and available resources required ongoing flexibility in accepting new concepts and ideas. The success of the project is documented in this report, as are suggestions for how other centers that experience similar challenging reorganizations can apply the lessons learned from our endeavors.

A historical perspective of anthracycline cardiotoxicity.

Anthracyclines remain important agents in the treatment of solid and hematological malignancy. Early experience with these drugs reported cardiac failure as an adverse event. Later, clinical recognition of cell injury at the time of administration was appreciated. This article explores the evolution of our understanding about anthracycline-associated cardiotoxicity, including the various strategies for the pretreatment assessment of patients for whom anthracyclines are contemplated, the frustrations associated with the lack of specific tests that could identify patients at risk of developing problems with their next 1 or 2 cycles, the concept of balancing oncologic benefit with cardiac risk in the treatment of cancer patients, and the newer strategies for reducing the potentially devastating complications of the treatment of malignant disease with anthracyclines.

Cardiac Safety of Osimertinib: A Review of Data.

PURPOSE: Osimertinib is a third-generation, CNS-active, irreversible, oral epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that potently and selectively inhibits both EGFR-TKI-sensitizing and T790M resistance mutations. We assess the cardiac failure risk in patients receiving osimertinib by evaluating the available data. METHODS: Post hoc analyses of cardiac data from (1) studies in patients with advanced non-small-cell lung cancer, FLAURA (osimertinib, n = 279; comparator EGFR-TKI, n = 277) and AURA3 (osimertinib, n = 279; chemotherapy, n = 140), and (2) a pooled data set of patients treated with osimertinib 80 mg from across the clinical trial program (n = 1,142), including cardiac failure-related adverse events and left ventricular ejection fraction (LVEF) reductions. An LVEF pharmacokinetic or pharmacodynamic analysis of the pooled data set was performed. The sponsor's global safety database was analyzed for cardiac failure-related adverse events, and a literature search was conducted. RESULTS: Decreases in LVEF from a baseline of ≥ 10 percentage points to an absolute value of < 50% following osimertinib treatment were observed in 8 (3.1%) and 14 (5.5%) patients in FLAURA and AURA3, respectively, and in 35 (3.9%) patients in the pooled population. Most events were asymptomatic and resolved without treatment of the event or osimertinib discontinuation. The pharmacokinetic or pharmacodynamic analysis did not indicate a relationship between exposure to osimertinib and decreases in LVEF from baseline. The database and literature search showed no specific trend or pattern that was suggestive of a safety issue in patients receiving osimertinib. CONCLUSION: These data do not suggest a causal relationship between osimertinib and cardiac failure. However, because of LVEF decreases that were observed in patients with cardiac risk factors before osimertinib treatment, cardiac monitoring, including an assessment of LVEF at baseline and during osimertinib treatment, is advised.

TAVR and cancer: machine learning-augmented propensity score mortality and cost analysis in over 30 million patients.

INTRODUCTION: Cardiovascular disease (CVD) and cancer are the top mortality causes globally, yet little is known about how the diagnosis of cancer affects treatment options in patients with hemodynamically compromising aortic stenosis (AS). Patients with cancer often are excluded from aortic valve replacement (AVR) trials including trials with transcatheter AVR (TAVR) and surgical AVR (SAVR). This study looks at how cancer may influence treatment options and assesses the outcome of patients with cancer who undergo SAVR or TAVR intervention. Additionally, we sought to quantitate and compare both clinical and cost outcomes for patients with and without cancer. METHODS: This population-based case-control study uses the most recent year available National Inpatient Sample (NIS (2016) from the United States Department of Health and Human Services' Agency for Healthcare Research and Quality (AHRQ). Machine learning augmented propensity score adjusted multivariable regression was conducted based on the likelihood of undergoing TAVR versus medical management (MM) and TAVR versus SAVR with model optimization supported by backward propagation neural network machine learning. RESULTS: Of the 30,195,722 total hospital admissions, 39,254 (0.13%) TAVRs were performed, with significantly fewer performed in patients with versus without cancer even in those of comparable age and mortality risk (23.82% versus 76.18%, p < 0.001) despite having similar hospital and procedural mortality. Multivariable regression in patients with cancer demonstrated that mortality was similar for TAVR, MM, and SAVR, though LOS and cost was significantly lower for TAVR versus MM and comparable for TAVR versus SAVR. Patients with prostate cancer constituted the largest primary cancer among TAVR patients including those with metastatic disease. There were no significant race or geographic disparities for TAVR mortality. DISCUSSION: Comparison of aortic valve intervention in patients with and without cancer suggests that interventions are underutilized in the cancer population. This study suggests that patients with cancer including those with metastasis have similar inpatient outcomes to patients without cancer. Further, patients who have symptomatic AS and those with higher risk aortic valve disease should be offered the benefit of intervention. Modern techniques have reduced intervention-related adverse events, provided improved quality of life, and appear to be cost effective; these advantages should not necessarily be denied to patients with co-existing cancer.

Updated results from the international phase III ALTTO trial (BIG 2-06/Alliance N063D).

AIM: To present the pre-specified analyses of >5-years follow-up of the Phase III ALTTO trial. PATIENTS AND METHODS: 8381 patients with stage I-III HER2 positive breast cancer randomised to chemotherapy plus 1-year of trastuzumab (T), oral lapatinib (L; no longer evaluated), trastuzumab followed by lapatinib (T→L), and lapatinib + trastuzumab (L+T). The primary endpoint was disease-free survival (DFS). A secondary analysis examined DFS treatment effects by hormone receptor status, nodal status and chemotherapy timing; time to recurrence; overall survival (OS) and safety (overall and cardiac). RESULTS: At a median follow-up of 6.9 years, 705 DFS events for L+T versus T were observed. Hazard Ratio (HR) for DFS was 0.86 (95% CI, 0.74-1.00) for L+T versus T and 0.93 (95% CI, 0.81-1.08) for T→L versus T. The 6-year DFS were 85%, 84%, and 82% for L+T, T→L, and T, respectively. HR for OS was 0.86 (95% CI, 0.70-1.06) for L+T versus T and 0.88 (95% CI, 0.71-1.08) for T→L versus T. The 6-year OS were 93%, 92%, and 91% for L+T, T→L, and T, respectively. Subset analyses showed a numerically better HR for DFS in favour of L+T versus T for the hormone-receptor-negative [HR 0.80 (95% CI, 0.64-1.00; 6-yr DFS% = 84% versus 80%)] and the sequential chemotherapy [HR 0.83 (95% CI, 0.69-1.00; 6-yr DFS% = 83% versus79%)] subgroups. CONCLUSION: T+L did not significantly improve DFS and OS over T alone, both with chemotherapy, and, therefore, cannot be recommended for adjuvant treatment of early-stage HER2-positive breast cancer. TRIAL REGISTRATION: clinicaltrials.gov Identifier NCT00490139.