Effect of Metformin Versus Placebo on New Primary Cancers in Canadian Cancer Trials Group MA.32: A Secondary Analysis of a Phase III Randomized Double-Blind Trial in Early Breast Cancer.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.Metformin has been associated with lower cancer risk in epidemiologic and preclinical research. In the MA.32 randomized adjuvant breast cancer trial, metformin (v placebo) did not affect invasive disease-free or overall survival. Here, we report metformin effects on the risk of new cancer. Between 2010 and 2013, 3,649 patients with breast cancer younger than 75 years without diabetes with high-risk T1-3, N0-3 M0 breast cancer (any estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2) were randomly assigned to metformin 850 mg orally twice a day or placebo twice a day for 5 years. New primary invasive cancers (outside the ipsilateral breast) developing as a first event were identified. Time to events was described by the competing risks method; two-sided likelihood ratio tests adjusting for age, BMI, smoking, and alcohol intake were used to compare metformin versus placebo arms. A total of 184 patients developed new invasive cancers: 102 metformin and 82 placebo, hazard ratio (HR), 1.25; 95% CI, 0.94 to 1.68; P = .13. These included 48 contralateral invasive breast cancers (27 metformin v 21 placebo), HR, 1.29; 95% CI, 0.72 to 2.27; P = .40 and 136 new nonbreast primary cancers (75 metformin v 61 placebo), HR, 1.24; 95% CI, 0.88 to 1.74; P = .21. Metformin did not reduce the risk of new cancer development in these nondiabetic patients with breast cancer.

Effect of Metformin vs Placebo on Invasive Disease-Free Survival in Patients With Breast Cancer: The MA.32 Randomized Clinical Trial.

Importance: Metformin, a biguanide commonly used to treat type 2 diabetes, has been associated with potential beneficial effects across breast cancer subtypes in observational and preclinical studies. Objective: To determine whether the administration of adjuvant metformin (vs placebo) to patients with breast cancer without diabetes improves outcomes. Design, Setting, and Participants: MA.32, a phase 3 randomized, placebo-controlled, double-blind trial, conducted in Canada, Switzerland, US, and UK, enrolled 3649 patients with high-risk nonmetastatic breast cancer receiving standard therapy between August 2010 and March 2013, with follow-up to October 2020. Interventions: Patients were randomized (stratified for hormone receptor [estrogen receptor and/or progesterone receptor {ER/PgR}] status, positive vs negative; body mass index, ≤30 vs >30; human epidermal growth factor receptor 2 [ERBB2, formerly HER2 or HER2/neu], positive vs negative; and any vs no chemotherapy) to 850 mg of oral metformin twice a day (n = 1824) or oral placebo twice a day (n = 1825) for 5 years. Main Outcomes and Measures: The primary outcome was invasive disease-free survival in hormone receptor-positive breast cancer. Of the 8 secondary outcomes, overall survival, distant relapse-free survival, and breast cancer-free interval were analyzed. Results: Of the 3649 randomized patients (mean age, 52.4 years; 3643 women [99.8%]), all (100%) were included in analyses. After a second interim analysis, futility was declared for patients who were ER/PgR-, so the primary analysis was conducted for 2533 patients who were ER/PgR+. The median duration of follow-up in the ER/PgR+ group was 96.2 months (range, 0.2-121 months). Invasive disease-free survival events occurred in 465 patients who were ER/PgR+. The incidence rates for invasive disease-free survival events were 2.78 per 100 patient-years in the metformin group vs 2.74 per 100 patient-years in the placebo group (hazard ratio [HR], 1.01; 95% CI, 0.84-1.21; P = .93), and the incidence rates for death were 1.46 per 100 patient-years in the metformin group vs 1.32 per 100 patient-years in the placebo group (HR, 1.10; 95% CI, 0.86-1.41; P = .47). Among patients who were ER/PgR-, followed up for a median of 94.1 months, incidence of invasive disease-free survival events was 3.58 vs 3.60 per 100 patient-years, respectively (HR, 1.01; 95% CI, 0.79-1.30; P = .92). None of the 3 secondary outcomes analyzed in the ER/PgR+ group had statistically significant differences. Grade 3 nonhematological toxic events occurred more frequently in patients taking metformin than in patients taking placebo (21.5% vs 17.5%, respectively, P = .003). The most common grade 3 or higher adverse events in the metformin vs placebo groups were hypertension (2.4% vs 1.9%), irregular menses (1.5% vs 1.4%), and diarrhea (1.9% vs 7.0%). Conclusions and Relevance: Among patients with high-risk operable breast cancer without diabetes, the addition of metformin vs placebo to standard breast cancer treatment did not significantly improve invasive disease-free survival. Trial Registration: ClinicalTrials.gov Identifier: NCT01101438.

Discordance between Immunohistochemistry and Erb-B2 Receptor Tyrosine Kinase 2 mRNA to Determine Human Epidermal Growth Factor Receptor 2 Low Status for Breast Cancer.

Novel human epidermal growth factor receptor 2 (HER2)-directed antibody-drug conjugates have demonstrated efficacy in HER2-low expressing breast cancers, which are currently defined as those with immunohistochemistry (IHC) scores of 1+ or 2+ with a negative in situ hybridization assay. However, current HER2 testing methods are designed to identify HER2-amplified tumors with high expression levels. The true definition of HER2-low expressing breast cancers remains controversial. Using quantitative molecular analysis of breast cancers based on RNA expression, the dynamic range of HER2 expression exceeds that detected by in situ IHC approaches. Erb-B2 receptor tyrosine kinase 2 (ERBB2) mRNA expression levels across IHC groups using patient samples derived from the Tamoxifen Exemestane Adjuvant Multicenter Trial were investigated. The standardized mean differences in ERBB2 mRNA scores in log base 2 are 0.47 (95% CI, 0.36-0.57), 0.58 (95% CI, 0.26-0.70), and 0.32 (95% CI, -0.12 to 0.75) when comparing IHC 0+ without staining versus IHC 0+ with some staining, IHC 0+ with some staining versus IHC 1+, and IHC 1+ versus IHC 2+/fluorescence in situ hybridization-negative, respectively. The results showed immunohistochemical methods have a comparatively limited dynamic range for measuring HER2 protein expression. The range of expression based on RNA abundance suggests a molecular method defining HER2-low cancers may better serve the treatment decision needs of this group. Indeed, the validity of RNA abundance to identify HER2-low cancers and predict treatment response needs to be further evaluated by prospective clinical trials.

Breast Cancer Index Is a Predictive Biomarker of Treatment Benefit and Outcome from Extended Tamoxifen Therapy: Final Analysis of the Trans-aTTom Study.

PURPOSE: The Breast Cancer Index (BCI) HOXB13/IL17BR (H/I) ratio predicts benefit from extended endocrine therapy in hormone receptor-positive (HR+) early-stage breast cancer. Here, we report the final analysis of the Trans-aTTom study examining BCI (H/I)'s predictive performance. EXPERIMENTAL DESIGN: BCI results were available for 2,445 aTTom trial patients. The primary endpoint of recurrence-free interval (RFI) and secondary endpoints of disease-free interval (DFI) and disease-free survival (DFS) were examined using Cox proportional hazards regression and log-rank test. RESULTS: Final analysis of the overall study population (N = 2,445) did not show a significant improvement in RFI with extended tamoxifen [HR, 0.90; 95% confidence interval (CI), 0.69-1.16; P = 0.401]. Both the overall study population and N0 group were underpowered due to the low event rate in the N0 group. In a pre-planned analysis of the N+ subset (N = 789), BCI (H/I)-High patients derived significant benefit from extended tamoxifen (9.7% absolute benefit: HR, 0.33; 95% CI, 0.14-0.75; P = 0.016), whereas BCI (H/I)-Low patients did not (-1.2% absolute benefit; HR, 1.11; 95% CI, 0.76-1.64; P = 0.581). A significant treatment-to-biomarker interaction was demonstrated on the basis of RFI, DFI, and DFS (P = 0.037, 0.040, and 0.025, respectively). BCI (H/I)-High patients remained predictive of benefit from extended tamoxifen in the N+/HER2- subgroup (9.4% absolute benefit: HR, 0.35; 95% CI, 0.15-0.81; P = 0.047). A three-way interaction evaluating BCI (H/I), treatment, and HER2 status was not statistically significant (P = 0.849). CONCLUSIONS: Novel findings demonstrate that BCI (H/I) significantly predicts benefit from extended tamoxifen in HR+ N+ patients with HER2- disease. Moreover, BCI (H/I) demonstrates significant treatment to biomarker interaction across survival outcomes.

Cancer Antigen 15-3/Mucin 1 Levels in CCTG MA.32: A Breast Cancer Randomized Trial of Metformin vs Placebo.

Background: Circulating levels of cancer antigen (CA) 15-3, a tumor marker and regulator of cellular metabolism, were reduced by metformin in a nonrandomized neoadjuvant study. We examined the effects of metformin (vs placebo) on CA 15-3 in participants of MA.32, a phase III randomized trial in early-stage breast cancer. Methods: A total of 3649 patients with T1-3, N0-3, M0 breast cancer were randomly assigned; pretreatment and 6-month on-treatment fasting plasma were centrally assayed for CA 15-3. Genomic DNA was analyzed for the rs11212617 single nucleotide polymorphism. Absolute and relative change of CA 15-3 (metformin vs placebo) were compared using Wilcoxon rank and t tests. Regression models adjusted for baseline differences and assessed key interactions. All statistical tests were 2-sided. Results: Mean (SD) age was 52.4 (10.0) years. The majority of patients had T2/3, node-positive, hormone receptor-positive, HER2-negative breast cancer treated with (neo)adjuvant chemotherapy and hormone therapy. Mean (SD) baseline CA 15-3 was 17.7 (7.6) and 18.0 (8.1 U/mL). At 6 months, CA 15-3 was statistically significantly reduced in metformin vs placebo arms (absolute geometric mean reduction in CA 15-3 = 7.7% vs 2.0%, P < .001; relative metformin: placebo level of CA 15-3 [adjusted for age, baseline body mass index, and baseline CA 15-3] = 0.94, 95% confidence interval = 0.92 to 0.96). This reduction was independent of tumor characteristics, perioperative systemic therapy, baseline body mass index, insulin, and the single nucleotide polymorphism status (all Ps > .11). Conclusions: Our observation that metformin reduces CA 15-3 by approximately 6% was corroborated in a large placebo-controlled randomized trial. The clinical implications of this reduction in CA 15-3 will be explored in upcoming efficacy analyses of breast cancer outcomes in MA.32.

Effect of metformin versus placebo on metabolic factors in the MA.32 randomized breast cancer trial.

Metformin may exert anticancer effects through indirect (mediated by metabolic changes) or direct mechanisms. The goal was to examine metformin impact on metabolic factors in non-diabetic subjects and determine whether this impact varies by baseline BMI, insulin, and rs11212617 SNP in CCTG MA.32, a double-blind placebo-controlled randomized adjuvant breast cancer (BC) trial. 3649 subjects with T1-3, N0-3, M0 BC were randomized; pretreatment and 6-month on-treatment fasting plasma was centrally assayed for insulin, leptin, highly sensitive C-reactive protein (hsCRP). Glucose was measured locally and homeostasis model assessment (HOMA) calculated. Genomic DNA was analyzed for the rs11212617 SNP. Absolute and relative change of metabolic factors (metformin versus placebo) were compared using Wilcoxon rank and t-tests. Regression models were adjusted for baseline differences and assessed interactions with baseline BMI, insulin, and the SNP. Mean age was 52 years. The majority had T2/3, node positive, hormone receptor positive, HER2 negative BC treated with (neo)adjuvant chemotherapy and hormone therapy. Median baseline body mass index (BMI) was 27.4 kg/m2 (metformin) and 27.3 kg/m2 (placebo). Median weight change was -1.4 kg (metformin) vs +0.5 kg (placebo). Significant improvements were seen in all metabolic factors, with 6 month standardized ratios (metformin/placebo) of 0.85 (insulin), 0.83 (HOMA), 0.80 (leptin), and 0.84 (hsCRP), with no qualitative interactions with baseline BMI or insulin. Changes did not differ by rs11212617 allele. Metformin (vs placebo) led to significant improvements in weight and metabolic factors; these changes did not differ by rs11212617 allele status.

Overestimation of Late Distant Recurrences in High-Risk Patients With ER-Positive Breast Cancer: Validity and Accuracy of the CTS5 Risk Score in the TEAM and IDEAL Trials.

PURPOSE: Most distant recurrences (DRs) in women with hormone receptor-positive breast cancer occur after 5 years from diagnosis. The Clinical Treatment Score post-5 years (CTS5) estimates DRs after 5 years of adjuvant endocrine therapy (AET). The aim of this study was to externally validate the CTS5 as a prognostic/predictive tool. METHODS: The CTS5 categorizes patients who have been disease free for 5 years into low, intermediate, and high risk and calculates an absolute risk for developing DRs between 5 and 10 years. Discrimination and calibration were assessed using data from the TEAM and IDEAL trials. The predictive value of the CTS5 was tested with data from the IDEAL trial. RESULTS: A total of 5,895 patients from the TEAM trial and 1,591 patients from the IDEAL trial were included. When assessing the CTS5 discrimination, significantly more DRs were found at 10 years after diagnosis in the CTS5 high- and intermediate-risk groups than in the low-risk group (hazard ratio, 5.7 [95% CI, 3.6 to 8.8] and 2.8 [95% CI, 1.7 to 4.4], respectively). In low- and intermediate-risk patients, the CTS5-predicted DR rates were higher, although not statistically significantly so, than observed rates. However, in high-risk patients, the CTS5-predicted DR rates were significantly higher than observed rates (29% v 19%, respectively; P < .001). The CTS5 was not predictive for extended AET duration. CONCLUSION: The CTS5 score as applied to patients treated in the TEAM and IDEAL cohorts discriminates between risk categories but overestimates the risk of late DRs in high-risk patients. Therefore, the numerical risk assessment from the CTS5 calculator in its current form should be interpreted with caution when used in daily clinical practice, particularly in high-risk patients.

Synchronous versus sequential chemo-radiotherapy in patients with early stage breast cancer (SECRAB): A randomised, phase III, trial.

BACKGROUND: The optimal sequence of adjuvant chemotherapy and radiotherapy for breast cancer is unknown. SECRAB assesses whether local control can be improved without increased toxicity. METHODS: SECRAB was a prospective, open-label, multi-centre, phase III trial comparing synchronous to sequential chemo-radiotherapy, conducted in 48 UK centres. Patients with invasive, early stage breast cancer were eligible. Randomisation (performed using random permuted block assignment) was stratified by centre, axillary surgery, chemotherapy, and radiotherapy boost. Permitted chemotherapy regimens included CMF and anthracycline-CMF. Synchronous radiotherapy was administered between cycles two and three for CMF or five and six for anthracycline-CMF. Sequential radiotherapy was delivered on chemotherapy completion. Radiotherapy schedules included 40 Gy/15F over three weeks, and 50 Gy/25F over five weeks. The primary outcome was local recurrence at five and ten years, defined as time to local recurrence, and analysed by intention to treat. ClinicalTrials.gov NCT00003893. FINDINGS: Between 02-July-1998 and 25-March-2004, 2297 patients were recruited (1150 synchronous and 1146 sequential). Baseline characteristics were balanced. With 10.2 years median follow-up, the ten-year local recurrence rates were 4.6% and 7.1% in the synchronous and sequential arms respectively (hazard ratio (HR) 0.62; 95% confidence interval (CI): 0.43-0.90; p = 0.012). In a planned sub-group analysis of anthracycline-CMF, the ten-year local recurrence rates difference were 3.5% versus 6.7% respectively (HR 0.48 95% CI: 0.26-0.88; p = 0.018). There was no significant difference in overall or disease-free survival. 24% of patients on the synchronous arm suffered moderate/severe acute skin reactions compared to 15% on the sequential arm (p < 0.0001). There were no significant differences in late adverse effects apart from telangiectasia (p = 0.03). INTERPRETATION: Synchronous chemo-radiotherapy significantly improved local recurrence rates. This was delivered with an acceptable increase in acute toxicity. The greatest benefit of synchronous chemo-radiation was in patients treated with anthracycline-CMF. FUNDING: Cancer Research UK (CR UK/98/001) and Pharmacia.

Ductal carcinoma in situ: to treat or not to treat, that is the question.

Ductal carcinoma in situ (DCIS) now represents 20-25% of all 'breast cancers' consequent upon detection by population-based breast cancer screening programmes. Currently, all DCIS lesions are treated, and treatment comprises either mastectomy or breast-conserving surgery supplemented with radiotherapy. However, most DCIS lesions remain indolent. Difficulty in discerning harmless lesions from potentially invasive ones can lead to overtreatment of this condition in many patients. To counter overtreatment and to transform clinical practice, a global, comprehensive and multidisciplinary collaboration is required. Here we review the incidence of DCIS, the perception of risk for developing invasive breast cancer, the current treatment options and the known molecular aspects of progression. Further research is needed to gain new insights for improved diagnosis and management of DCIS, and this is integrated in the PRECISION (PREvent ductal Carcinoma In Situ Invasive Overtreatment Now) initiative. This international effort will seek to determine which DCISs require treatment and prevent the consequences of overtreatment on the lives of many women affected by DCIS.

Pathway-based subnetworks enable cross-disease biomarker discovery.

Biomarkers lie at the heart of precision medicine. Surprisingly, while rapid genomic profiling is becoming ubiquitous, the development of biomarkers usually involves the application of bespoke techniques that cannot be directly applied to other datasets. There is an urgent need for a systematic methodology to create biologically-interpretable molecular models that robustly predict key phenotypes. Here we present SIMMS (Subnetwork Integration for Multi-Modal Signatures): an algorithm that fragments pathways into functional modules and uses these to predict phenotypes. We apply SIMMS to multiple data types across five diseases, and in each it reproducibly identifies known and novel subtypes, and makes superior predictions to the best bespoke approaches. To demonstrate its ability on a new dataset, we profile 33 genes/nodes of the PI3K pathway in 1734 FFPE breast tumors and create a four-subnetwork prediction model. This model out-performs a clinically-validated molecular test in an independent cohort of 1742 patients. SIMMS is generic and enables systematic data integration for robust biomarker discovery.

Predictive Biomarkers for Endocrine Therapy: Retrospective Study in Tamoxifen and Exemestane Adjuvant Multinational (TEAM) Trial.

Background: Aromatase inhibitors improve disease-free survival compared with tamoxifen in postmenopausal women with hormone receptor-positive breast cancer. The Tamoxifen and Exemestane Adjuvant Multinational (TEAM) trial compared exemestane monotherapy with sequential therapy of tamoxifen followed by exemestane. The trial failed to show a statistically significant difference between treatment arms. A robust translational program was established to investigate predictive biomarkers. Methods: A tissue microarray was retrospectively constructed using a subset of patient tissues (n = 4631) from the TEAM trial (n = 9766). Immunohistochemistry was performed for biomarkers, classed into three groups: MAPK pathway, NF-kappa B pathway, and estrogen receptor (ER) phosphorylation. Expression was analyzed for association with relapse-free survival (RFS) at 2.5 and 10 years and treatment regimen using Kaplan-Meier curves and log-rank analysis. All statistical tests were two-sided. Results: In univariate analysis, ER167 (hazard ratio [HR] = 0.71, 95% confidence interval [CI] = 0.59 to 0.85, P < .001), IKKα (HR = 0.74, 95% CI = 0.60 to 0.92, P = .005), Raf-1338 (HR = 0.64, 95% CI = 0.52 to 0.80, P < .001), and p44/42 MAPK202/204 (HR = 0.77, 95% CI = 0.64 to 0.92, P = .004) were statistically significantly associated with improved RFS at 10 years in patients receiving sequential therapy. Associations were strengthened when IKKα, Raf-1338, and ER167 were combined into a cumulative prognostic score (HR = 0.64, 95% CI = 0.52 to 0.77, P < .001). Patients with an all negative IKKα, Raf-1338, and ER167 score favored exemestane monotherapy (odds ratio = 0.56, 95% CI = 0.35 to 0.90). In multivariable analysis, the IKKα, Raf-1338, and ER167 score (P = .001) was an independent prognostic factor for RFS at 10 years in patients receiving sequential therapy. Conclusions: The IKKα, Raf-1338, and ER167 score is an independent predictive biomarker for lower recurrence on sequential therapy. Negative expression may further offer predictive value for exemestane monotherapy.

Tumor PIK3CA Genotype and Prognosis in Early-Stage Breast Cancer: A Pooled Analysis of Individual Patient Data.

Purpose Phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha ( PIK3CA) mutations are frequently observed in primary breast cancer. We evaluated their prognostic relevance by performing a pooled analysis of individual patient data. Patients and Methods Associations between PIK3CA status and clinicopathologic characteristics were tested by applying Cox regression models adjusted for age, tumor size, nodes, grade, estrogen receptor (ER) status, human epidermal growth factor receptor 2 (HER2) status, treatment, and study. Invasive disease-free survival (IDFS) was the primary end point; distant disease-free survival (DDFS) and overall survival (OS) were also assessed, overall and by breast cancer subtypes. Results Data from 10,319 patients from 19 studies were included (median OS follow-up, 6.9 years); 1,787 patients (17%) received chemotherapy, 4,036 (39%) received endocrine monotherapy, 3,583 (35%) received both, and 913 (9%) received none or their treatment was unknown. PIK3CA mutations occurred in 32% of patients, with significant associations with ER positivity, increasing age, lower grade, and smaller size (all P < .001). Prevalence of PIK3CA mutations was 18%, 22%, and 37% in the ER-negative/HER2-negative, HER2-positive, and ER-positive/HER2-negative subtypes, respectively. In univariable analysis, PIK3CA mutations were associated with better IDFS (HR, 0.77; 95% CI, 0.71 to 0.84; P < .001), with evidence for a stronger effect in the first years of follow-up (0 to 5 years: HR, 0.73; 95% CI, 0.66 to 0.81; P < .001; 5 to 10 years: HR, 0.82; 95% CI, 0.68 to 0.99; P = .037); > 10 years: (HR, 1.15; 95% CI, 0.84 to 1.58; P = .38; P heterogeneity = .02). In multivariable analysis, PIK3CA genotype remained significant for improved IDFS ( P = .043), but not for the DDFS and OS end points. Conclusion In this large pooled analysis, PIK3CA mutations were significantly associated with a better IDFS, DDFS, and OS, but had a lesser prognostic effect after adjustment for other prognostic factors.

Nonoperative Management for Invasive Breast Cancer After Neoadjuvant Systemic Therapy: Conceptual Basis and Fundamental International Feasibility Clinical Trials.

With current advances in neoadjuvant systemic therapy (NST) and improved breast imaging, the potential of nonoperative therapy for invasive breast cancer has emerged as a viable option when utilizing meticulous image-guided percutaneous biopsy to document pathologic complete response. Feasibility clinical trials utilizing this approach are being performed by teams of investigators from single and multicenter/cooperative groups around the world. Imaging alone after NST lacks sufficient sensitivity and specificity in predicting pCR and therefore cannot be utilized for clinical selection of patients for omission of surgery. Imaging with adequate sampling after NST of the residual lesions (or around the remaining clip if a complete radiologic response occurs) appears to be essential in selecting patients with pCR to lower the false-negative rates based on initial reported feasibility studies to identify pCR without surgery that range from 5 to 49%. In this manuscript, recently completed, ongoing, and planned clinical feasibility trials and a new omission of surgery trial are described. Drastic rethinking of all diagnostic and therapeutic management strategies that are ordinarily utilized for patients who receive standard breast cancer surgery is required. A roadmap of essential questions and issues that will have to be resolved as the field of nonoperative breast cancer management advances is described in detail.

HER2 status predicts for upfront AI benefit: A TRANS-AIOG meta-analysis of 12,129 patients from ATAC, BIG 1-98 and TEAM with centrally determined HER2.

BACKGROUND: A meta-analysis of the effects of HER2 status, specifically within the first 2-3 years of adjuvant endocrine therapy, has the potential to inform patient selection for upfront aromatase inhibitor (AI) therapy or switching strategy tamoxifen followed by AI. The pre-existing standardisation of methodology for HER2 (immunohistochemistry/fluorescence in situ hybridization) facilitates analysis of existing data for this key marker. METHODS: Following a prospectively designed statistical analysis plan, patient data from 3 phase III trials Arimidex, Tamoxifen, Alone or in Combination Trial (ATAC), Breast International Group (BIG) 1-98 and Tamoxifen Exemestane Adjuvant Multicentre Trial (TEAM)] comparing an AI to tamoxifen during the first 2-3 years of adjuvant endocrine treatment were collected and a treatment-by-marker analysis of distant recurrence-free interval-censored at 2-3 years treatment - for HER2 status × AI versus tamoxifen treatment was performed to address the clinical question relating to efficacy of 'upfront' versus 'switch' strategies for AIs. RESULTS: A prospectively planned, patient-level data meta-analysis across 3 trials demonstrated a significant treatment (AI versus tamoxifen) by marker (HER2) interaction in a multivariate analysis; (interaction hazard ratio [HR] = 1.61, 95% CI 1.01-2.57; p < 0.05). Heterogeneity between trials did not reach statistical significance. The HER2 negative (HER2-ve) group gained greater benefit from AI versus tamoxifen (HR = 0.70, 95% CI 0.56-0.87) than the HER2-positive (HER2+ve) group (HR = 1.13, 95% CI 0.75-1.71). However, the small number of HER2+ve cases (n = 1092 across the 3 trials) and distant recurrences (n = 111) may explain heterogeneity between trials. CONCLUSIONS: A patient-level data meta-analysis demonstrated a significant interaction between HER2 status and treatment with AI versus tamoxifen in the first 2-3 years of adjuvant endocrine therapy. Patients with HER2-ve cancers experienced improved outcomes (distant relapse) when treated with upfront AI rather than tamoxifen, whilst patients with HER2+ve cancers fared no better or slightly worse in the first 2-3 years. However, the small number of HER2+ve cancers/events may explain a large degree of heterogeneity in the HER2+ve groups across all 3 trials. Other causes, perhaps related to subtle differences between AIs, cannot be excluded and warrant further exploration.

Addition of gemcitabine to paclitaxel, epirubicin, and cyclophosphamide adjuvant chemotherapy for women with early-stage breast cancer (tAnGo): final 10-year follow-up of an open-label, randomised, phase 3 trial.

BACKGROUND: The tAnGo trial was designed to investigate the potential role of gemcitabine when added to anthracycline and taxane-containing adjuvant chemotherapy for early breast cancer. When this study was developed, gemcitabine had shown significant activity in metastatic breast cancer, and there was evidence of a favourable interaction with paclitaxel. METHODS: tAnGo was an international, open-label, randomised, phase 3 superiority trial that enrolled women aged 18 years or older with newly diagnosed, early-stage breast cancer who had a definite indication for chemotherapy, any nodal status, any hormone receptor status, Eastern Cooperative Oncology Group performance status of 0-1, and adequate bone marrow, hepatic, and renal function. Women were recruited from 127 clinical centres and hospitals in the UK and Ireland, and randomly assigned (1:1) to one of two treatment regimens: epirubicin, cyclophosphamide, and paclitaxel (four cycles of 90 mg/m2 intravenously administered epirubicin and 600 mg/m2 intravenously administered cyclophosphamide on day 1 every 3 weeks, followed by four cycles of 175 mg/m2 paclitaxel as a 3 h infusion on day 1 every 3 weeks) or epirubicin, cyclophosphamide, and paclitaxel plus gemcitabine (the same chemotherapy regimen as the other group, with the addition of 1250 mg/m2 gemcitabine to the paclitaxel cycles, administered intravenously as a 0·5 h infusion on days 1 and 8 every 3 weeks). Patients were randomly assigned by a central computerised deterministic minimisation procedure, with stratification by country, age, radiotherapy intent, nodal status, and oestrogen receptor and HER-2 status. The primary endpoint was disease-free survival and the trial aimed to detect 5% differences in 5-year disease-free survival between the treatment groups. Recruitment completed in 2004 and this is the final, intention-to-treat analysis. This trial is registered with EudraCT (2004-002927-41), ISRCTN (51146252), and ClinicalTrials.gov (NCT00039546). FINDINGS: Between Aug 22, 2001, and Nov 26, 2004, 3152 patients were enrolled and randomly assigned to epirubicin, cyclophosphamide, paclitaxel, and gemcitabine (gemcitabine group; n=1576) or to epirubicin, cyclophosphamide, and paclitaxel (control group; n=1576). 11 patients (six in the gemcitabine group and five in the control group) were ineligible because of pre-existing metastases and were therefore excluded from the analysis. At this protocol-specified final analysis (median follow-up 10 years [IQR 10-10]), 1087 disease-free survival events and 914 deaths had occurred. Disease-free survival did not differ significantly between the treatment groups at 10 years (65% [63-68] in the gemcitabine group vs 65% [62-67] in the control group), and median disease-free survival was not reached (adjusted hazard ratio 0·97 [95% CI 0·86-1·10], p=0·64). Toxicity, dose intensity, and a detailed safety substudy showed both regimens to be safe, deliverable, and tolerable. Grade 3 and 4 toxicities were reported at expected levels in both groups. The most common were neutropenia (527 [34%] of 1565 patients in the gemcitabine group vs 412 [26%] of 1567 in the control group), myalgia and arthralgia (207 [13%] vs 186 [12%]), fatigue (207 [13%] vs 152 [10%]), infection (202 [13%] vs 141 [9%]), vomiting (143 [9%] vs 108 [7%]), and nausea (132 [8%] vs 102 [7%]). INTERPRETATION: The addition of gemcitabine to anthracycline and taxane-based adjuvant chemotherapy at this dose and schedule confers no therapeutic advantage in terms of disease-free survival in early breast cancer, although it can cause increased toxicity. Therefore, gemcitabine has not been added to standard adjuvant chemotherapy in breast cancer for any subgroup. FUNDING: Cancer Research UK core funding for Clinical Trials Unit at the University of Birmingham, Eli Lilly, Bristol-Myers Squibb, and Pfizer.

Comparing Breast Cancer Multiparameter Tests in the OPTIMA Prelim Trial: No Test Is More Equal Than the Others.

BACKGROUND: Previous reports identifying discordance between multiparameter tests at the individual patient level have been largely attributed to methodological shortcomings of multiple in silico studies. Comparisons between tests, when performed using actual diagnostic assays, have been predicted to demonstrate high degrees of concordance. OPTIMA prelim compared predicted risk stratification and subtype classification of different multiparameter tests performed directly on the same population. METHODS: Three hundred thirteen women with early breast cancer were randomized to standard (chemotherapy and endocrine therapy) or test-directed (chemotherapy if Oncotype DX recurrence score >25) treatment. Risk stratification was also determined with Prosigna (PAM50), MammaPrint, MammaTyper, NexCourse Breast (IHC4-AQUA), and conventional IHC4 (IHC4). Subtype classification was provided by Blueprint, MammaTyper, and Prosigna. RESULTS: Oncotype DX predicted a higher proportion of tumors as low risk (82.1%, 95% confidence interval [CI] = 77.8% to 86.4%) than were predicted low/intermediate risk using Prosigna (65.5%, 95% CI = 60.1% to 70.9%), IHC4 (72.0%, 95% CI = 66.5% to 77.5%), MammaPrint (61.4%, 95% CI = 55.9% to 66.9%), or NexCourse Breast (61.6%, 95% CI = 55.8% to 67.4%). Strikingly, the five tests showed only modest agreement when dichotomizing results between high vs low/intermediate risk. Only 119 (39.4%) tumors were classified uniformly as either low/intermediate risk or high risk, and 183 (60.6%) were assigned to different risk categories by different tests, although 94 (31.1%) showed agreement between four of five tests. All three subtype tests assigned 59.5% to 62.4% of tumors to luminal A subtype, but only 121 (40.1%) were classified as luminal A by all three tests and only 58 (19.2%) were uniformly assigned as nonluminal A. Discordant subtyping was observed in 123 (40.7%) tumors. CONCLUSIONS: Existing evidence on the comparative prognostic information provided by different tests suggests that current multiparameter tests provide broadly equivalent risk information for the population of women with estrogen receptor (ER)-positive breast cancers. However, for the individual patient, tests may provide differing risk categorization and subtype information.

Validation of the IHC4 Breast Cancer Prognostic Algorithm Using Multiple Approaches on the Multinational TEAM Clinical Trial.

CONTEXT: Hormone receptors HER2/neu and Ki-67 are markers of residual risk in early breast cancer. An algorithm (IHC4) combining these markers may provide additional information on residual risk of recurrence in patients treated with hormone therapy. OBJECTIVE: To independently validate the IHC4 algorithm in the multinational Tamoxifen Versus Exemestane Adjuvant Multicenter Trial (TEAM) cohort, originally developed on the trans-ATAC (Arimidex, Tamoxifen, Alone or in Combination Trial) cohort, by comparing 2 methodologies. DESIGN: The IHC4 biomarker expression was quantified on TEAM cohort samples (n = 2919) by using 2 independent methodologies (conventional 3,3'-diaminobezidine [DAB] immunohistochemistry with image analysis and standardized quantitative immunofluorescence [QIF] by AQUA technology). The IHC4 scores were calculated by using the same previously established coefficients and then compared with recurrence-free and distant recurrence-free survival, using multivariate Cox proportional hazards modeling. RESULTS: The QIF model was highly significant for prediction of residual risk (P < .001), with continuous model scores showing a hazard ratio (HR) of 1.012 (95% confidence interval [95% CI]: 1.010-1.014), which was significantly higher than that for the DAB model (HR: 1.008, 95% CI: 1.006-1.009); P < .001). Each model added significant prognostic value in addition to recognized clinical prognostic factors, including nodal status, in multivariate analyses. Quantitative immunofluorescence, however, showed more accuracy with respect to overall residual risk assessment than the DAB model. CONCLUSIONS: The use of the IHC4 algorithm was validated on the TEAM trial for predicting residual risk in patients with breast cancer. These data support the use of the IHC4 algorithm clinically, but quantitative and standardized approaches need to be used.

Predicting Anthracycline Benefit: TOP2A and CEP17-Not Only but Also.

PURPOSE: Evidence supporting the clinical utility of predictive biomarkers of anthracycline activity is weak, with a recent meta-analysis failing to provide strong evidence for either HER2 or TOP2A. Having previously shown that duplication of chromosome 17 pericentromeric alpha satellite as measured with a centromere enumeration probe (CEP17) predicted sensitivity to anthracyclines, we report here an individual patient-level pooled analysis of data from five trials comparing anthracycline-based chemotherapy with CMF (cyclophosphamide, methotrexate, and fluorouracil) as adjuvant chemotherapy for early breast cancer. PATIENTS AND METHODS: Fluorescent in situ hybridization for CEP17, HER2, and TOP2A was performed in three laboratories on samples from 3,846 of 4,864 eligible patients from five trials evaluating anthracycline-containing chemotherapy versus CMF. Methodologic differences did not affect HER2-to-CEP17 ratios but necessitated different definitions for CEP17 duplication: > 1.86 observed copies per cell for BR9601, NEAT, Belgian, and DBCG89D trials and > 2.25 for the MA.5 trial. RESULTS: Fluorescent in situ hybridization data were available in 89.3% (HER2), 83.9% (CEP17), and 80.6% (TOP2A) of 3,846 patient cases with available tissue. Both CEP17and TOP2A treatment-by-marker interactions remained significant in adjusted analyses for recurrence-free and overall survival, whereas HER2 did not. A combined CEP17 and TOP2A-adjusted model predicted anthracycline benefit across all five trials for both recurrence-free (hazard ratio, 0.64; 95% CI, 0.51 to 0.82; P = .001) and overall survival (hazard ratio, 0.66; 95% CI, 0.51 to 0.85; P = .005). CONCLUSION: This prospectively planned individual-patient pooled analysis of patient cases from five adjuvant trials confirms that patients whose tumors harbor either CEP17 duplication or TOP2A aberrations, but not HER2 amplification, benefit from adjuvant anthracycline chemotherapy.

Mutational analysis of PI3K/AKT signaling pathway in tamoxifen exemestane adjuvant multinational pathology study.

PURPOSE: Deregulation of key PI3K/AKT pathway genes may contribute to endocrine resistance in breast cancer (BC). PIK3CA is the most frequently mutated gene in luminal BC (35%); however, the effect of mutations in helical versus kinase domains remains controversial. We hypothesize that improved outcomes occur in patients with estrogen receptor­positive (ER positive) BC receiving endocrine therapy and possessing PIK3CA mutations. MATERIALS AND METHODS: DNA was extracted from 4,540 formalin-fixed paraffin-embedded BC samples from the Exemestane Versus Tamoxifen-Exemestane pathology study. Mutational analyses were performed for 25 mutations (PIK3CAx10, AKT1x1, KRASx5, HRASx3, NRASx2 and BRAFx4). RESULTS: PIK3CA mutations were frequent (39.8%), whereas RAS/RAF mutations were rare (1%). In univariable analyses PIK3CA mutations were associated with significantly improved 5-year distant relapse-free survival (DRFS; HR, 0.76; 95% CI, 0.63 to 0.91; P = .003). However, a multivariable analysis correcting for known clinical and biologic prognostic factors failed to demonstrate that PIK3CA mutation status is an independent prognostic marker for DRFS (HR, 0.92; 95% CI, 0.75 to 1.12; P = .4012). PIK3CA mutations were more frequent in low-risk luminal BCs (e.g., grade 1 nodev 3, node-negative v -positive), confounding the relationship between mutations and outcome. CONCLUSION: PIK3CA mutations are present in approximately 40% of luminal BCs but are not an independent predictor of outcome in the context of endocrine therapy, whereas RAS/RAF mutations are rare inluminal BC. A complex relationship between low-risk cancers and PIK3CA mutations was identified. Although the PI3K/AKT pathway remains a viable therapeutic target as the result of ahigh mutation frequency, PIK3CA mutations do not seem to affect residual risk following treatment with endocrine therapy.

Systematic review of lapatinib in combination with letrozole compared with other first-line treatments for hormone receptor positive(HR+) and HER2+ advanced or metastatic breast cancer(MBC).

BACKGROUND: Third-generation aromatase inhibitors (letrozole, anastrozole) have shown superior efficacy in early and advanced breast cancer compared with tamoxifen. For HR+, HER2+ MBC, combination of an AI with an anti-HER2 agent (lapatinib or trastuzumab) has shown clinical benefit. METHODS: Six databases were searched until January 2009 for randomized controlled clinical trials, assessing the safety and efficacy of first-line treatments for postmenopausal women with HR+ and HER2 (ErbB2) positive MBC, who have not received prior therapy for advanced or metastatic disease. Relevant interventions were lapatinib, aromatase inhibitors, tamoxifen, and trastuzumab. Outcomes included overall survival (OS), progression-free-survival (PFS), time-to-progression (TTP), and objective response rate (ORR). RESULTS: Eighteen studies (62 papers) were included. Lapatinib + letrozole was significantly superior to letrozole alone based on a direct head-to-head study in terms of PFS/TTP and ORR. Using a network meta-analysis, compared with lapatinib + letrozole, tamoxifen (HR = 0.45 (95% CI: 0.32, 0.65) and anastrozole (HR = 0.53 (0.36, 0.80)) scored significantly worse in terms of PFS/TTP and ORR (tamoxifen: OR = 0.25 (0.12, 0.53), anastrozole: OR = 0.27 (0.12, 0.58). The combination also seemed significantly superior to exemestane in terms of PFS/TTP (HR = 0.52 (0.34, 0.79)). Lapatinib + letrozole also seemed better, although not significantly, in terms of OS versus tamoxifen: HR = 0.74 (0.49, 1.12), anastrozole: HR = 0.71 (0.45, 1.14) and exemestane: HR = 0.65 (0.39, 1.11). When compared with trastuzumab + anastrozole, lapatinib + letrozole seemed to be better in terms of OS (HR = 0.85 (0.47, 1.54)), PFS/TTP (HR = 0.89 (0.54, 1.47)) and ORR (OR = 0.92 (0.24, 3.48)), although, none of these results were significant. DISCUSSION: Lapatinib + letrozole was significantly superior to letrozole in terms of PFS/TTP and ORR based on a direct head-to-head study. Indirect comparisons appeared to favor lapatinib + letrozole versus other first-line treatments used in this patient population in terms of three main outcomes: OS, PFS/TTP and ORR. Indirect comparison results are based on a network analysis for which the basic assumptions of homogeneity, similarity and consistency were not fulfilled. Therefore, despite the fact that these are the best available data, the results need to be interpreted with caution.