Germline mutations in BRCA1/2 predispose individuals to breast cancer (termed germline-mutated BRCA1/2 breast cancer, gBRCA-BC) by impairing homologous recombination (HR) and causing genomic instability. HR also repairs DNA lesions caused by platinum agents and PARP inhibitors. Triple-negative breast cancers (TNBCs) harbor subpopulations with BRCA1/2 mutations, hypothesized to be especially platinum-sensitive. Cancers in putative 'BRCAness' subgroups-tumors with BRCA1 methylation; low levels of BRCA1 mRNA (BRCA1 mRNA-low); or mutational signatures for HR deficiency and those with basal phenotypes-may also be sensitive to platinum. We assessed the efficacy of carboplatin and another mechanistically distinct therapy, docetaxel, in a phase 3 trial in subjects with unselected advanced TNBC. A prespecified protocol enabled biomarker-treatment interaction analyses in gBRCA-BC and BRCAness subgroups. The primary endpoint was objective response rate (ORR). In the unselected population (376 subjects; 188 carboplatin, 188 docetaxel), carboplatin was not more active than docetaxel (ORR, 31.4% versus 34.0%, respectively; P = 0.66). In contrast, in subjects with gBRCA-BC, carboplatin had double the ORR of docetaxel (68% versus 33%, respectively; biomarker, treatment interaction P = 0.01). Such benefit was not observed for subjects with BRCA1 methylation, BRCA1 mRNA-low tumors or a high score in a Myriad HRD assay. Significant interaction between treatment and the basal-like subtype was driven by high docetaxel response in the nonbasal subgroup. We conclude that patients with advanced TNBC benefit from characterization of BRCA1/2 mutations, but not BRCA1 methylation or Myriad HRD analyses, to inform choices on platinum-based chemotherapy. Additionally, gene expression analysis of basal-like cancers may also influence treatment selection.

Summary Background Circulating tumour DNA (ctDNA) testing might provide a current assessment of the genomic profile of advanced cancer, without the need to repeat tumour biopsy. We aimed to assess the accuracy of ctDNA testing in advanced breast cancer and the ability of ctDNA testing to select patients for mutation-directed therapy. Methods We did an open-label, multicohort, phase 2a, platform trial of ctDNA testing in 18 UK hospitals. Participants were women (aged ≥18 years) with histologically confirmed advanced breast cancer and an Eastern Cooperative Oncology Group performance status 0–2. Patients had completed at least one previous line of treatment for advanced breast cancer or relapsed within 12 months of neoadjuvant or adjuvant chemotherapy. Patients were recruited into four parallel treatment cohorts matched to mutations identified in ctDNA: cohort A comprised patients with ESR1 mutations (treated with intramuscular extended-dose fulvestrant 500 mg); cohort B comprised patients with HER2 mutations (treated with oral neratinib 240 mg, and if oestrogen receptor-positive with intramuscular standard-dose fulvestrant); cohort C comprised patients with AKT1 mutations and oestrogen receptor-positive cancer (treated with oral capivasertib 400 mg plus intramuscular standard-dose fulvestrant); and cohort D comprised patients with AKT1 mutations and oestrogen receptor-negative cancer or PTEN mutation (treated with oral capivasertib 480 mg). Each cohort had a primary endpoint of confirmed objective response rate. For cohort A, 13 or more responses among 78 evaluable patients were required to infer activity and three or more among 16 were required for cohorts B, C, and D. Recruitment to all cohorts is complete and long-term follow-up is ongoing. This trial is registered with ClinicalTrials.gov , NCT03182634 ; the European Clinical Trials database, EudraCT2015-003735-36; and the ISRCTN registry, ISRCTN16945804. Findings Between Dec 21, 2016, and April 26, 2019, 1051 patients registered for the study, with ctDNA results available for 1034 patients. Agreement between ctDNA digital PCR and targeted sequencing was 96–99% (n=800, kappa 0·89–0·93). Sensitivity of digital PCR ctDNA testing for mutations identified in tissue sequencing was 93% (95% CI 83–98) overall and 98% (87–100) with contemporaneous biopsies. In all cohorts, combined median follow-up was 14·4 months (IQR 7·0–23·7). Cohorts B and C met or exceeded the target number of responses, with five (25% [95% CI 9–49]) of 20 patients in cohort B and four (22% [6–48]) of 18 patients in cohort C having a response. Cohorts A and D did not reach the target number of responses, with six (8% [95% CI 3–17]) of 74 in cohort A and two (11% [1–33]) of 19 patients in cohort D having a response. The most c...

Introduction: Subgroups within sporadic triple negative breast cancers (TNBCs) appear to share impaired DNA damage response mechanisms with BRCA1/2 mutation-associated breast cancers. This has been hypothesised to confer particular sensitivity to DNA-damaging platinum chemotherapy. The TNT trial, a randomized phase III trial in women with metastatic or recurrent locally advanced TNBC or BRCA1/2 mutation-associated breast cancer, aimed to test this hypothesis and examine treatment effect in biological subgroups. Patients & Methods: Eligible patients had either ER-, PR-, HER2- breast cancer or were known BRCA1/2 carriers (any ER/PR/HER2). Patients were randomized (1:1) to receive either C (AUC 6 q3wk) or D (100mg/m2 q3wk) for 6-8 cycles or until disease progression if sooner and could cross over to the alternative treatment on confirmed progression. Ineligible patients included those who had ECOG performance status >2, received adjuvant taxane therapy in the last 12 mths, any previous treatment with a platinum chemotherapy, or previous non-anthracycline chemotherapy for metastatic disease. For consenting patients a blood sample and archived tissue samples were obtained for BRCA1/2 genotyping and central biomarker analysis (primary tumour, lymph nodes and recurrent tumour biopsy if available) of subtypes within TNBC and biomarkers of DNA repair deficiency. The primary endpoint was RECIST objective tumour response up to cycle 6 of randomised treatment. Secondary endpoints included toxicity, progression free survival (PFS), time to progression and overall survival. TNT aimed to detect a 15% improvement in ORR with C compared to D, with planned target sample size range of 370-450 depending on assumed ORR in D patients (2-sided α=0.05, power=90%). 376 (188 C, 188 D) were recruited from 74 UK centres between Apr 08 and Mar 14. Results: A snapshot of the data was taken on 30/5/14 at which point 336 (89.4%) patients had experienced a PFS event, with overall median PFS time of 4.4 mths. Median age of patients was 55 yrs (IQR 48-63). 366/376 (97%) patients had TNBC of whom 18 were also known BRCA1/2 mutation carriers, with the remaining 10 patients receptor +ve and BRCA1/2 carriers. 338/376 (90%) had metastatic and 38/376 (10%) recurrent locally advanced disease. 53% had liver or lung metastases affecting the parenchyma and 34% had received previous adjuvant taxane therapy. Median time from initial diagnosis to entering TNT was 2.2 yrs (IQR 1.5-3.5). Primary tumour tissue has currently been received for 277 patients, blood from 286 patients and recurrent tumour tissue from 85 patients. Discussion: TNT will report evidence on the activity of single agent platinum chemotherapy compared with single agent taxane in patients with TNBC and BRCA1/2 associated breast cancer. Correlative analyses of BRCA1/2 mutation status, subtypes and DNA repair biomarkers will also be reported. TNT will be the first randomised trial to report the activity of platinum compared with standard chemotherapy within TNBC subtypes and in relation to BRCA1/2 mutation status and DNA repair biomarkers. Safety, tolerability and response to crossover treatment will also be presented. Citation Format: Andrew Tutt, Paul Ellis, Lucy Kilburn, Cheryl Gilett, Sarah Pinder, Jacinta Abraham, Sophie Barrett, Peter Barrett-Lee, Stephen Chan, Maggie Cheang, Mitch Dowsett, Lisa Fox, Patrycja Gazinska, Anita Grigoriadis, Alexander Gutin, Catherine Harper-Wynne, Matthew Hatton, Sarah Kernaghan, Jerry Lanchbury, James Morden, Julie Owen, Jyoti Parikh, Peter Parker, Nazneen Rahman, Rebecca Roylance, Adam Shaw, Ian Smith, Rose Thompson, Kirsten Timms, Holly Tovey, Andrew Wardley, Gregory Wilson, Mark Harries, Judith Bliss. The TNT trial: A randomized phase III trial of carboplatin (C) compared with docetaxel (D) for patients with metastatic or recurrent locally advanced triple negative or BRCA1/2 breast cancer (CRUK/07/012) [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr S3-01.

The genomics of advanced breast cancer (ABC) has been described through tumour tissue biopsy sequencing, although these approaches are limited by geographical and temporal heterogeneity. Here we use plasma circulating tumour DNA sequencing to interrogate the genomic profile of ABC in 800 patients in the plasmaMATCH trial. We demonstrate diverse subclonal resistance mutations, including enrichment of HER2 mutations in HER2 positive disease, co-occurring ESR1 and MAP kinase pathway mutations in HR + HER2− disease that associate with poor overall survival (p = 0.0092), and multiple PIK3CA mutations in HR + disease that associate with short progression free survival on fulvestrant (p = 0.0036). The fraction of cancer with a mutation, the clonal dominance of a mutation, varied between genes, and within hotspot mutations of ESR1 and PIK3CA. In ER-positive breast cancer subclonal mutations were enriched in an APOBEC mutational signature, with second hit PIK3CA mutations acquired subclonally and at sites characteristic of APOBEC mutagenesis. This study utilises circulating tumour DNA analysis in a large clinical trial to demonstrate the subclonal diversification of pre-treated advanced breast cancer, identifying distinct mutational processes in advanced ER-positive breast cancer, and novel therapeutic opportunities.

Summary Background Alveolar soft-part sarcoma (ASPS) is a rare soft-tissue sarcoma that is unresponsive to chemotherapy. Cediranib, a tyrosine-kinase inhibitor, has shown substantial activity in ASPS in non-randomised studies. The Cediranib in Alveolar Soft Part Sarcoma (CASPS) study was designed to discriminate the effect of cediranib from the intrinsically indolent nature of ASPS. Methods In this double-blind, placebo-controlled, randomised, phase 2 trial, we recruited participants from 12 hospitals in the UK (n=7), Spain (n=3), and Australia (n=2). Patients were eligible if they were aged 16 years or older; metastatic ASPS that had progressed in the previous 6 months; had an ECOG performance status of 0–1; life expectancy of more than 12 weeks; and adequate bone marrow, hepatic, and renal function. Participants had to have no anti-cancer treatment within 4 weeks before trial entry, with exception of palliative radiotherapy. Participants were randomly assigned (2:1), with allocation by use of computer-generated random permuted blocks of six, to either cediranib (30 mg orally, once daily) or matching placebo tablets for 24 weeks. Treatment was supplied in number-coded bottles, masking participants and clinicians to assignment. Participants were unblinded at week 24 or sooner if they had progression defined by Response Evaluation Criteria in Solid Tumors (version 1.1); those on placebo crossed over to cediranib and all participants continued on treatment until progression or death. The primary endpoint was percentage change in sum of target marker lesion diameters between baseline and week 24 or progression if sooner, assessed in the evaluable population (all randomly assigned participants who had a scan at week 24 [or sooner if they progressed] with target marker lesions measured). Safety was assessed in all participants who received at least one dose of study drug. This study is registered with ClinicalTrials.gov , number NCT01337401 ; the European Clinical Trials database, number EudraCT2010-021163-33; and the ISRCTN registry, number ISRCTN63733470 recruitment is complete and follow-up is ongoing. Findings Between July 15, 2011, and July 29, 2016, of 48 participants recruited, all were randomly assigned to cediranib (n=32) or placebo (n=16). 23 (48%) were female and the median age was 31 years (IQR 27–45). Median follow-up was 34·3 months (IQR 23·7–55·6) at the time of data cutoff for these analyses (April 11, 2018). Four participants in the cediranib group were not evaluable for the primary endpoint (one did not start treatment, and three did not have their scan at 24 weeks). Median percentage change in sum of target marker lesion diameters for the evaluable population was −8·3% (IQR −26·5 to 5·9) with cediranib versus 13·4% (IQR 1·1 to 21·3) with placebo (one-sided p=0·0010). The most common grade 3 adverse events on (blinded) cediranib were hypertension (six [19%] of ...