ABSTRACT
Objective: During the COVID-19 pandemic, cancer patients had restricted access to standard of care tissue biopsy. Liquid biopsy assays using next generation sequencing technology provides a less invasive method for determining circulating tumour mutations (ctDNA) associated with targeted treatments or prognosis. As part of deploying technology to help cancer patients obtain molecular testing, a clinical program was initiated to offer liquid biopsy testing for Canadian patients with advanced or metastatic breast cancer. Method(s): Blood was drawn in two 10 mL StreckTM DNA BCTs and sent to the CAP/CLIA/DAP accredited Imagia Canexia Health laboratory for testing using the clinically validated Follow ItTM liquid biopsy assay. Plasma was isolated using a double spin protocol and plasma cell-free DNA (cfDNA) extracted using an optimized Promega Maxwell RSC method. Extracted cfDNA was amplified using the multiplex amplicon-based hotspot 30 or 38 gene panel and sequenced. An inhouse developed bioinformatics pipeline and reporting platform were used to identify pathogenic single nucleotide variants (SNVs), indels (insertions and deletions), and gene amplification. Included in the panel are genes associated with metastatic breast cancer: AKT1, BRAF, ERBB2, ESR1, KRAS, PIK3CA, TP53. Result(s): To identify biomarkers, 1214 metastatic or advanced breast cancer patient cfDNA samples were tested. There were 15 cases sent for repeat testing. We reported 48% of samples harboring pathogenic ctDNA mutations in TP53 (22%), PIK3CA (19%), ESR1 (18%), AKT1 (2%), ERBB2 (1.5%). Co-occurring variants were identified in samples with ESR1/PIK3CA as well as TP53/PIK3CA (both p-values <0.001). Interestingly, 29% of samples with mutated ESR1 harbored >= 2 ESR1 ctDNA mutations. In 56% of cases, previous molecular testing indicated the cancer subtype as hormone receptor (ER, PR) positive with/without HER2 negative status. In this specific subgroup, 49% harbored ctDNA mutations with 63% of those being PIK3CA and/or ESR1 mutations. Conclusion(s): A population of Canadian women with metastatic breast cancer were tested using a liquid biopsy gene panel during the COVID-19 pandemic for identification of biomarkers for targeted therapeutic options. Over 50% of the samples were identified as hormone positive, with greater than 60% harboring PIK3CA and ESR1 ctDNA mutations. Studies have shown that metastatic PIK3CA mutated ER-positive/HER2-negative tumors are predictive to respond to alpelisib therapy and have FDA and Health Canada approval. Additionally, ESR1 mutations are associated with acquired resistance to antiestrogen therapies, and interestingly we identified 29% of ESR1 mutated samples with multiple mutations possibly indicating resistance subclones. In future studies, longitudinal monitoring for presence of multiple targetable and resistance mutations could be utilized to predict or improve clinical management.
ABSTRACT
Background: During the COVID-19 pandemic, Twitter has been instrumental in accelerating knowledge dissemination and forging collaborations within the medical community and amongst patient advocates. Tweetchats within Twitter are scheduled conversations on a specific topic. In oncology, Tweetchats have been used by cancer advocates to spread awareness and for patient and caregiver education. A colorectal cancer (CRC) specific tweetchat did not previously exist. This describes the creation, and experiences with a CRC specific tweetchat. Method(s): The #CRCTrialsChat tweetchat was created by a patient advocate for colorectal cancer patients, caregivers and clinicians to meet and exchange clinical trial-related information. Two gastrointestinal (GI) medical oncologists and two radiation oncologists were enlisted as moderators. The topic for each session is chosen by the patient advocate, who creates an outline and divides the content, which is designed to last a one hour session. The idea is to create engaging, technical, but easy to understand content. Each moderator then works on the answers to their assigned section, which is edited to fit tweet character limit. Sessions may also have guest moderators with expertise on a specific topic. Through tweeting, moderators answer specific questions that come up during the session and later. Result(s): To date, we have had four sessions covering the following topics: Clinical trial basics, CRC Updates from ASCO22, ClinicalTrialFinders and BRAF-mutated tumors. The content created has been simple and engaging, the format has functioned smoothly, and the reach of #CRCTrialsChat has been steadily increasing. After the most recent session on BRAF in September 2022, the @CRCTrialsChat has 281 followers, 17K impressions and 14.6K profile visits, a reflection of its excellent content. From a clinician perspective, this is a great format to interact with colleagues, discuss enrolling trials and also become familiar with using Twitter. Conclusion(s): A CRC clinical trial focused tweetchat is an engaging way to deliver trial-related content to an audience of clinicians, patients and caregivers. The current format appears to be an effective way to create and disseminate information. Future sessions will focus on ctDNA, molecular markers such as KRAS and HER2, and rectal cancer trials. Our hope is that #CRCTrialsChat will stimulate continued patient and clinician engagement, increase awareness of clinical trials, enhance trial participation and initiate patient-centric research and collaborations.
ABSTRACT
Background: RET fusions are found in 1-2% of patients (pts) with advanced non-small cell lung cancer (aNSCLC). Targeted therapy with RET inhibitors (RETi) significantly improved prognosis. Molecular mechanisms of resistance are still incompletely characterized. Methods: This multicentric retrospective study included 24 centres. Eligible pts had a RET+ aNSCLC, were treated with a RETi and had at least one molecular profile by next-generation sequencing (NGS), performed before and/or after RETi, on tissue and/or plasma samples. Primary resistance under RETi was defined as disease progression (PD) within 6 months of therapy. Results: 95 patients were included with 112 biopsies: 93 at baseline, 19 at PD. 17 patients had paired NGS (baseline and PD). Median age was 65 years (range 56-72);62% were female, 54% were never smokers, 17% had brain metastasis (BM) at diagnosis. 55 patients received pralsetinib, 36 selpercatinib, 4 other RETi. Overall, median PFS under RETi was 17.1 months (95%CI 12.6-28). Primary resistance to RETi occurred in 22 (23%) patients. Primary resistant versus durable responders to RETi had non-adenocarcinoma histology in 9% vs 46% (p=0.61), smoking history in 57% vs 40% (p=0.21), BM in 5% vs 21% (p=0.1), TP53 mutations in 37% vs 22% (p=0.23). KRAS G12V mutation and SMARCA4 alterations were found only in poor responders (4.5% vs 0%, p=0.2;and 25% vs 0%, p=0.04, respectively). Among biopsies at PD (N=19, 13 liquid and 6 tissue biopsies), 7/13 (54%) liquid biopsies failed due to insufficient ctDNA. In 12 evaluable pts, 3 (25%) acquired secondary RET mutations (2 G810S and 1 S904F), 3 (25%) had novel RET rearrangements (2 in intron 11, 1 RET-DOCK1, 1 RET-CSGALNACT2) and 3 (25%) pts had off-target alterations (2 MET and 1 MYC amplification). Three pts (25%) developed novel TP53 mutations, while 3 (25%) had no novel identifiable alterations at PD. Conclusions: SMARCA4 and KRAS co-mutations may have a role in primary resistance to RETi. Secondary RET mutations, novel RET rearrangements and MET/MYC amplifications were identified after treatment with RETi. More than half of pts had insufficient ctDNA at PD, making tissue biopsy essential to identify resistance mechanisms. Legal entity responsible for the study: Institut Gustave Roussy. Funding: Has not received any funding. Disclosure: V. Fallet: Financial Interests, Personal, Advisory Board: AstraZeneca, BMS, Takeda, Roche, Pfizer, Sanofi, Sandoz, Jansen;Financial Interests, Personal, Invited Speaker: AstraZeneca, BMS, Takeda, Pfizer, MSD;Financial Interests, Personal, Expert Testimony: GSK, Boehringer. C. Audigier-Valette: Financial Interests, Personal, Advisory Role: AbbVie, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Ipsen, Eli Lilly, Novartis, Pfizer, and Roche. A. Russo: Financial Interests, Personal, Advisory Board: Pfizer, AstraZeneca, MSD, Novartis;Financial Interests, Personal, Writing Engagements: AstraZeneca, Novartis. A. Calles Blanco: Financial Interests, Personal, Advisory Board: AstraZeneca, Boehringer Ingelheim, Pfizer, Roche, Lilly, Merck Sharp & Dohme, Novartis, Bristol-Myers Squibb, Takeda, Sanofi;Financial Interests, Personal, Other, Speaker honoraria: Bayer;Financial Interests, Institutional, Research Grant, Drug-only for Investigator-initiated trial: Merck Sharp & Dohme. P. Iranzo Gomez: Financial Interests, Personal, Advisory Role: Bristol-Myers Squibb Recipient, F. Hoffmann, La Roche AG, Merck Sharp & Dohme, Boehringer Ingelheim, MSD Oncology, Rovi, Yowa Kirin, Grunenthal Pharma S.A., Pfizer. M. Tagliamento: Financial Interests, Personal, Other, medical writer: Novartis, Amgen;Financial Interests, Personal, Invited Speaker, travel/accommodation: Roche, Bristol-Myers Squibb, AstraZeneca, Takeda. L. Mezquita: Financial Interests, Personal, Advisory Board: Takeda, AstraZeneca, Roche;Financial Interests, Personal, Invited Speaker: Roche, BMS, AstraZeneca, Takeda;Financial Interests, Personal, Research Grant, SEOM Beca Retorno 2019: BI;Financial Interests, Personal, Research Grant, ESMO TR Research Fellowship 2019: BMS;Financial Interests, Institutional, Research Grant, COVID research Grant: Amgen;Financial Interests, Institutional, Invited Speaker: Inivata, Stilla. C. Lindsay: Financial Interests, Institutional, Principal Investigator: Roche, Amgen, BI;Financial Interests, Personal, Advisory Role: CBPartners, Amgen. S. Ponce: Financial Interests, Institutional, Principal Investigator: Merck Sharp and Dohme, F. Hoffmann-La Roche, Foundation Medicine, PharmaMar. Personal fees: Merck Sharp and Dohme, Bristol-Myers Squibb, F. Hoffmann-La Roche, Foundation Medicine, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Pfizer, Amgen, Celgene.;Financial Interests, Personal, Advisory Board: Merck Sharp and Dohme, Bristol-Myers Squibb, F. Hoffmann-La Roche, Foundation Medicine, AstraZeneca, Boehringer Ingelheim, Eli Lilly, Pfizer, Amgen, Celgene.;Non-Financial Interests, Personal, Other: Merck Sharp and Dohme, Bristol-Myers Squibb, F. Hoffmann-La Roche. M. Aldea: Financial Interests, Personal, Invited Speaker, travel/accommodation: Sandoz. All other authors have declared no conflicts of interest.
ABSTRACT
Background Detection of circulating tumour DNA (ctDNA) in patients (pts) who have completed treatment for early-stage triple negative breast cancer (TNBC) is associated with a very high risk of future relapse. Identifiying those at high risk of subsequent relapse may allow tailoring of further therapy to delay or prevent recurrence. The c-TRAK TN trial assessed the utility of prospective ctDNA surveillance in pts treated for TNBC and the activity of pembrolizumab (P) in pts with ctDNA detected. Methods c-TRAK TN, a multi-centre phase II trial with integrated prospective screening component, enrolled pts with early-stage TNBC and either residual disease following neoadjuvant chemotherapy, or tumour size >20mm and/or axillary lymph node involvement if adjuvant chemotherapy was given. Tumour tissue was sequenced to identify somatic mutations suitable for tracking using personalised digital PCR ctDNA assays (BioRad QX200). Pts had "active" ctDNA surveillance via blood sample testing every 3 months to 12 months (potential up to 18 months if S samples missed due to COVID) during which time if ctDNA was detected (ctDNA+) pts could be randomised 2:1 to P (200mg i.v. q 3 weeks for 1 year) or observation (Obs). Pts and clinicians were blinded to ctDNA+ results unless they were allocated P, when staging scans were done and those free of clinical recurrence started treatment. Following advice from the Independent Data Monitoring Committee, the Obs arm closed on 16/06/2020 with all subsequent ctDNA+ pts allocated P. Following the completion of active ctDNA surveillance, 3-monthly visits continued to 24 months to be analysed retrospectively. The aim was to recruit 150 pts to ctDNA surveillance, assuming 30% would be ctDNA+ within 12 months, allowing ctDNA+ rate to be estimated with a 2-sided 95%CI of +/-7.3%. Co-primary endpoints are i) rates of ctDNA detection by 12 and 24 months from start of ctDNA surveillance;ii) rates of sustained ctDNA clearance on P defined as absence of detectable ctDNA, or disease recurrence 6 months after starting P. Results 208 pts were registered between 30/01/18 and 06/12/19, 185 had tumour sequenced, 171 (92.4%) had trackable mutations, and 161 entered ctDNA surveillance. The rate of ctDNA detection by 12 months after start of surveillance was 27.3% (44/161, 95% CI 20.6-34.9). ctDNA+ rates from baseline, 3, 6, 9 and 12 month ctDNA samples were 23/161 (14.3%), 6/115 (5.2%), 6/99 (5.1%), 7/84 (8.3%), and 2/84 (2.4%) respectively. An additional 2 pts were ctDNA+ on COVID extended active surveillance at 15 (1/51, 2%) or 18 months (1/11, 9%). 7 pts relapsed without prior ctDNA detection. 45 pts entered the therapeutic component of the trial (initially 31 to P and 14 to Obs). 1 Obs pt was re-allocated to P. Of pts allocated to P, 72% (23/32) had metastatic disease at time of ctDNA detection on staging scans (75% (12/16) who were ctDNA+ at baseline and 69% (11/16) at other timepoints). 4 pts declined to start P, largely due to COVID concerns. Of the 5 pts who commenced P, at the time of analysis none achieved sustained ctDNA clearance and 4 had recurred. In pts allocated to Obs, median time to recurrence was 4.1 months (95% CI: 3.2-not-defined). Conclusion The c-TRAK TN trial is to our knowledge the first study to assess the proof-of-principle of whether ctDNA assays have clinical utility in guiding further therapy in TNBC. Relatively few pts commenced P treatment precluding assessment of potential activity. At enrollment, patients had a relatively high of rate of undiagnosed metastatic disease when imaged. Our findings have implications for future trial design, emphasizing the importance of early start of ctDNA testing, and more sensitive and/or more frequent ctDNA testing regimes.
ABSTRACT
Background: Most patients with pancreatic cancer (PC) and biliary tract cancer (BTC) present with advanced disease. In confirmed cases, circulating tumour DNA (ctDNA) may be detected through liquid biopsy in 80-90%. Obtaining a diagnostic biopsy can be technically challenging, require complex invasive procedures and may not be feasible due to comorbidity. Reduction in capacity of aerosol generating diagnostic procedures in many healthcare systems due to COVID19 has highlighted the unmet need for simple, noninvasive diagnostic tools. We piloted the use of ctDNA to support the diagnostic pathway in patients with suspected cancer across 6 tumour types, here we present its use in PC/BTC. Methods: This single centre prospective cohort pilot trial was conducted at the Royal Marsden from June 2020 to August 2021. 16 patients were planned each in the PC and BTC cohorts. Eligibility included radiologically suspicious PC/BTC without histological diagnosis, patients with prior non-diagnostic biopsy and inaccessible tumours. Liquid biopsy for ctDNA was collected for plasma based next generation sequencing, using a custom 59 gene panel of common variants in PC/BTC tumours, including analysis for somatic, copy number and structural variants. Clonal haematopoiesis of indeterminate potential (CHIP) and germline variants were identified and subtracted. A molecular tumour board (MTB) reviewed results for interpretation and clinical context. Primary outcome was the proportion of patients with a ctDNA result consistent with a diagnosis of malignancy following MTB discussion. Results: 32 patients with suspected PC (n= 16) and BTC (n=16) were recruited. Baseline characteristics are shown in table. ctDNA was detected in 69% off, 23 patients had a subsequent biopsy. The sensitivity and specificity of ctDNA as a diagnostic tool was 80% (90% CI 49.3-96.3) and 100% (90% CI 36.8-100) for PC respectively, and 100% (90% CI 60.7-100) and 75% (90% CI 24.9- 98.7) for BTC respectively. There were 2 false negatives in the PC cohort subsequently diagnosed with PC, and 1 false positive in the BTC cohort subsequently diagnosed with oesophageal cancer. Conclusions: ctDNA can be used to support a diagnosis of cancer in patients with radiologically suspected PC/BTC. A blood first, tissue second strategy in the diagnosis of PC/BTC could improve diagnostic efficiency, speed, and add resilience to the current diagnostic pathway.