SUMMARY BACKGROUND Greater than 50% of recurrences in estrogen receptor-positive (ER+) breast cancer occur after 5 years of adjuvant endocrine therapy. Biomarkers capable of improving the risk-benefit of extended adjuvant endocrine therapy for these late recurrences would be clinically valuable. We compared the prognostic ability of the Breast Cancer Index (BCI), Oncotype DX Recurrence Score (RS) and IHC4 for both early and late recurrence among patients with ER+, node negative (N0) disease within the ATAC clinical trial. METHODS BCI was performed from 1102 primary tumor samples from ER+ patients and two versions (BCI-C (primary) and BCI-L (secondary), based on cubic and linear combinations of the variables) were evaluated. RS and IHC4 values were previously derived. Prognostic discrimination for early (<5y) and late recurrence (5–10y) was assessed. To evaluate the ability of the biomarkers to predict recurrence beyond standard clinicopathological parameters, the likelihood-ratio chi-square (LR-Δχ2) was calculated from Cox proportional hazards models. The primary endpoint was distant recurrence (DR). FINDINGS In the primary analysis of 665 ER+ N0 patients, categorical BCI-C demonstrated significant differences in risk of DR over 10 years (P<0·0001). In the secondary analysis, BCI-L proved to be a much stronger predictor, and BCI-L, IHC4 and RS had significant prognostic performance for early DR (BCI-L, p<0·0002), while only BCI-L was significant for late DR (LR-Δχ2: 7·97, p=0·0048). For risk of early DR at 5 years, BCI-L classified 59% (390/665), 25% (166/665) and 16% (109/665) of patients with 1.3% (0.5% – 3.1%), 5.6% (2.9% – 10.5%) and 18.1% (12.0% – 27.0%) for low, intermediate and high risk, respectively. For risk of late DR at 10 years, BCI-L classified 61% (366/596), 25% (146/596) and 14% (84/596) of patients with 3.5% (2.0% – 6.1%), 13.4% (8.5% – 20.8%) and 13.3% (7.4% – 23.4%) for low, intermediate and high, respectively. INTERPRETATION While all three biomarkers predicted for early DR, BCI-L was the only significant prognostic for risk of late DR. The three BCI-L groups identified two risk populations for both early and late DR with 84% (556/665) of patients having low risk for early DR, and a smaller population (39%, 230/596) having high risk for late DR who may benefit from extended endocrine or other therapy. FUNDING Avon Foundation, National Institutes of Health, Breast Cancer Foundation, DOD Breast Cancer Research Program, Susan G. Komen for the Cure, Breakthrough Breast Cancer through the Mary-Jean Mitchell Green Foundation, Astrazeneca, NIHR Biomedical Research Centre at the Royal Marsden.

Background Preoperative and perioperative aromatase inhibitor (POAI) therapy has the potential to improve outcomes in women with operable oestrogen receptor-positive primary breast cancer. It has also been suggested that tumour Ki67 values after 2 weeks (Ki67 2W ) of POAI predicts individual patient outcome better than baseline Ki67 (Ki67 B ). The POETIC trial aimed to test these two hypotheses. MethodsPOETIC was an open-label, multicentre, parallel-group, randomised, phase 3 trial (done in 130 UK hospitals) in which postmenopausal women aged at least 50 years with WHO performance status 0-1 and hormone receptor-positive, operable breast cancer were randomly assigned (2:1) to POAI (letrozole 2•5 mg per day orally or anastrozole 1 mg per day orally) for 14 days before and following surgery or no POAI (control). Adjuvant treatment was given as per UK standard local practice. Randomisation was done centrally by computer-generated permuted block method (variable block size of six or nine) and was stratified by hospital. Treatment allocation was not masked. The primary endpoint was time to recurrence. A key second objective explored association between Ki67 (dichotomised at 10%) and disease outcomes. The primary analysis for clinical endpoints was by modified intention to treat (excluding patients who withdrew consent). For Ki67 biomarker association and endpoint analysis, the evaluable population included all randomly assigned patients who had paired Ki67 values available. This study is registered with ClinicalTrials.gov, NCT02338310; the European Clinical Trials database, EudraCT2007-003877-21; and the ISRCTN registry, ISRCTN63882543. Recruitment is complete and long-term follow-up is ongoing.

Background-The impact of QRS morphology and duration on the effectiveness of cardiac resynchronization therapy (CRT) has been usually assessed separately. The interaction between these 2 simple ECG parameters and their effect on CRT has not been systematically assessed in a large-scale clinical trial. Methods and Results-The Resynchronization-Defibrillation for Ambulatory Heart Failure Trial showed that implantable cardioverter defibrillator-CRT was associated with a significant reduction in the primary end point of all-cause mortality or heart failure hospitalization. For this substudy, we excluded patients in atrial fibrillation and those with a previous pacemaker. All baseline ECGs were reviewed by a panel of 3 experienced electrocardiographers. A total of 1483 patients were included in this study. Of these, 1175 had left bundle-branch block (LBBB) and 308 had non-LBBB. In patients with LBBB receiving implantable cardioverter defibrillator-CRT, there was a reduction in the primary outcome and in each individual component of the primary outcome. Furthermore, there was continuous relationship between QRS duration and extent of benefit. In patients with non-LBBB and QRS ≥160 ms, the hazard ratio for the primary outcome was 0.52 (0.29-0.96; P=0.033); in patients with QRS <160 ms, the hazard ratio was 1.38 (0.88-2.14; P=0.155). Conclusions-In patients with LBBB, there was a continuous relationship between broader QRS and greater benefit from implantable cardioverter defibrillator-CRT. However, our data do not support the use of implantable cardioverter defibrillator-CRT in patients with non-LBBB, especially when the QRS duration is <160 ms. There may be some delayed benefit when the QRS is ≥160 ms, but this needs further investigation. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00251251.