PETAL protocol: a phase Ib study of pembrolizumab after transarterial chemoembolization in hepatocellular carcinoma.

Transarterial chemoembolization (TACE) is the treatment of choice for intermediate-stage hepatocellular carcinoma (HCC). Recent data suggest that TACE may boost the efficacy of anti-PD-1 immunotherapy. The authors present the trial protocol for PETAL, a phase Ib study, which will assess the safety and bioactivity of pembrolizumab, an anti-PD-1 antibody, following TACE in HCC. After a run-in phase evaluating six patients to establish preliminary safety, up to 26 additional participants will be enrolled. Pembrolizumab will be administered three-times weekly for 1 year or until progression, starting 30-45 days after TACE. The primary objective is to determine safety and the secondary objective is to preliminarily evaluate efficacy. Radiological responses will be evaluated every four cycles. Clinical Trial Registration: NCT03397654 (ClinicalTrials.gov).

Qualification of tumour mutational burden by targeted next-generation sequencing as a biomarker in hepatocellular carcinoma.

BACKGROUND & AIMS: Tumour mutational burden (TMB) predicts improved response and survival to immunotherapy. In this pilot study, we optimized targeted next-generation sequencing (tNGS) to estimate TMB in hepatocellular carcinoma (HCC). METHODS: We sequenced 48 non-paired samples (21 fresh-frozen [FF] and 27 paraffin-embedded [FFPE]), among which 11 FFPE samples were pretreated with uracil-DNA glycosylase (UDG). Thirty samples satisfied post-sequencing quality control. High/low TMB was defined by median number of mutations/Mb (Mut/Mb), across different minimum allele frequency (MAF) thresholds (≥0.05, ≥0.1 and ≥0.2). RESULTS: Eligible patients (n = 29) were cirrhotic (84%) with TNM stage I-II HCC (75%). FFPE samples had higher TMB (median 958.39 vs 2.51 Mut/Mb, P < .0001), estimated deamination counts (median 1335.50 vs 0, P < .0001) and C > T transitions at CpG sites (median 60.3% vs 9.1%, P = .002) compared to FF. UDG-treated samples had lower TMB (median 4019.92 vs 353 Mut/Mb, P = .041) and deamination counts (median 6393.5 vs 328.5, P = .041) vs untreated FFPE. At 0.2 MAF threshold with UDG treatment, median TMB was 5.48 (range 1.68-16.07) and did not correlate with salient pathologic features of HCC, including survival. CONCLUSION: While tNGS on fresh HCC samples appears to be the optimal source of tumour DNA, the low median TMB values observed may limit the role of TMB as a predictor of response to immunotherapy in HCC.

Immunotoxicity from checkpoint inhibitor therapy: clinical features and underlying mechanisms.

Immune checkpoint inhibition with monoclonal antibodies is becoming increasingly commonplace in cancer medicine, having contributed to a widening of therapeutic options across oncological indications. Disruption of immune tolerance is the key mechanism of action of checkpoint inhibitors and although immune-related adverse events are a typical class effect of these compounds, the relationship between toxicity and response is not fully understood. Awareness and vigilance are paramount in recognizing potentially life-threatening toxicities and managing them in a timely manner. In this review article, we provide an overview of the clinical features, pathological findings and management principles of common immune-related toxicities, attempting to provide mechanistic insight into an increasingly common complication of cancer therapy.

Insights into the metastatic cascade through research autopsies.

Metastasis is a complex process and the leading cause of cancer-related death globally. Recent studies have demonstrated that genomic sequencing data from paired primary and metastatic tumours can be used to trace the evolutionary origins of cells responsible for metastasis. This approach has yielded new insights into the genomic alterations that engender metastatic potential, and the mechanisms by which cancer spreads. Given that the reliability of these approaches is contingent upon how representative the samples are of primary and metastatic tumour heterogeneity, we review insights from studies that have reconstructed the evolution of metastasis within the context of their cohorts and designs. We discuss the role of research autopsies in achieving the comprehensive sampling necessary to advance the current understanding of metastasis.

Integrated phenotyping of the anti-cancer immune response in HIV-associated hepatocellular carcinoma.

Background & Aims: HIV-seropositivity shortens survival in patients with hepatocellular carcinoma (HCC). Although risk factors for HCC including HCV infection can influence T cell phenotype, it is unknown whether HIV can influence functional characteristics of the T cell infiltrate. Methods: From the Liver Cancer in HIV biorepository, we derived 129 samples of transplanted (76%) or resected (20%) HCC in eight European and North American centres. We profiled intra- and peritumoural tissue to evaluate regulatory CD4+/FOXP3+ and immune-exhausted CD8+/PD1+ T cells in HIV+ (n = 66) and HIV- (n = 63) samples. We performed targeted transcriptomics and T-cell receptor sequencing in a restricted subset of samples evaluated in relationship with HIV status. We correlated immunopathologic features with patients' characteristics including markers of HIV infection. Results: Of the 66 HIV+ patients, 83% were HCV coinfected with an undetectable HIV viral load (51%) and a median blood CD4+ cell count of 430 cells/mm3 (range 15-908). Patients who were HIV+ were compared with HIV- controls with similar staging characteristics including Barcelona Clinic Liver Cancer (BCLC) stage A-B (86% vs. 83%, p = 0.16), <3 nodules (90% vs. 83%, p = 0.3) and median alpha-foetoprotein values (10.9 vs. 12.8 ng/ml, p = 0.72). HIV+ samples had higher PD-L1 expression rates in tumour tissue (51% vs. 8% p <0.0001) and displayed denser intratumoural CD4+/FOXP3+ (p <0.0001), CD8+/PD1+ (p <0.0001), with lower total peritumoural CD4+ (p <0.0001) and higher peritumoural CD8+/PD1+ (p <0.0001). Gene set analysis revealed HIV+ cases to have evidence of dysregulated adaptive and innate immunity. Tumour-infiltrating lymphocyte clonality was not influenced by HIV status. Conclusions: HIV-associated HCC harbours a profoundly immune-exhausted tumour microenvironment, warranting prospective testing of immunotherapy in this treatment-deprived patient population. Impact and Implications: Hepatocellular carcinoma is a non-AIDS defining malignancy characterised by poor survival. The programmed cell death (PD-1) pathway governs antiviral and anticancer immune exhaustion and is a therapeutic target in HCC. This study highlights how HIV infection is associated with significantly higher PD-L1 expression in HCC cells and in the surrounding microenvironment, leading to changes in cytotoxic and regulatory T cell function and dysregulation of proinflammatory pathways. Taken together, our results suggest dysfunctional T cell immunity as a mechanism of worse outcome in these patients and suggest clinical testing of checkpoint inhibitors in HIV-associated HCC.

Immune Checkpoint Inhibitors for Child-Pugh Class B Advanced Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis.

Importance: Immune checkpoint inhibitors (ICIs) are increasingly used in patients with advanced hepatocellular carcinoma (HCC). However, data on ICI therapy in patients with advanced HCC and impaired liver function are scarce. Objective: To conduct a systematic review and meta-analysis to determine the efficacy and safety of ICI treatment for advanced HCC with Child-Pugh B liver function. Data Sources: PubMed, Embase, Web of Science, and Cochrane Library were searched for relevant studies from inception through June 15, 2022. Study Selection: Randomized clinical trials, cohort studies, or single-group studies that investigated the efficacy or safety of ICI therapy for Child-Pugh B advanced HCC were included. Data Extraction and Synthesis: The Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline was followed to extract data. A random-effects model was adopted if the heterogeneity was significant (I2 > 50%); otherwise, a fixed-effect model was used. Main Outcomes and Measures: The objective response rate (ORR) and overall survival (OS) were considered to be the primary efficacy outcomes of ICI treatment for Child-Pugh B advanced HCC, and the incidence of treatment-related adverse events (trAEs) was set as the primary measure for the safety outcome. Results: A total of 22 studies including 699 patients with Child-Pugh B and 2114 with Child-Pugh A advanced HCC comprised the analytic sample (median age range, 53-73 years). Upon pooled analysis, patients treated with ICIs in the Child-Pugh B group had an ORR of 14% (95% CI, 11%-17%) and disease control rate (DCR) of 46% (95% CI, 36%-56%), with a median OS of 5.49 (95% CI, 3.57-7.42) months and median progression-free survival of 2.68 (95% CI, 1.85-3.52) months. The rate of any grade trAEs in the Child-Pugh B group was 40% (95% CI, 34%-47%) and of grade 3 or higher trAEs was 12% (95% CI, 6%-23%). Compared with the Child-Pugh A group, the ORR (odds ratio, 0.59; 95% CI, 0.43-0.81; P < .001) and DCR (odds ratio, 0.64; 95% CI, 0.50-0.81; P < .001) were lower in the Child-Pugh B group. Child-Pugh B was independently associated with worse OS in patients with advanced HCC treated with ICIs (hazard ratio, 2.72 [95% CI, 2.34-3.16]; adjusted hazard ratio, 2.33 [95% CI, 1.81-2.99]). However, ICIs were not associated with increased trAEs in the Child-Pugh B group. Conclusions and Relevance: The findings of this systematic review and meta-analysis suggest that although the safety of ICI treatment was comparable between patients with HCC with vs without advanced liver disease and the treatment resulted in a significant number of radiologic responses, survival outcomes are still inferior in patients with worse liver function. More study is needed to determine the effectiveness of ICI treatment in this population.

Patterns and outcomes of subsequent therapy after immune checkpoint inhibitor discontinuation in HCC.

The availability of immune checkpoint inhibitors (ICIs) for the management of advanced hepatocellular cancer (HCC) has changed the treatment paradigm. There are emerging questions regarding the efficacy of subsequent anticancer therapies. The primary aim of this retrospective, multicenter study was to examine the types of anticancer treatment received after ICIs and to assess the impact on post-ICI survival. We established an international consortium of 11 tertiary-care referral centers located in the USA (n = 249), Europe (n = 74), and Asia (n = 97), and described patterns of care following ICI therapy. The impact of subsequent therapy on overall survival (OS) was estimated using the Kaplan-Meier method and presented with a 95% confidence interval (CI). A total of 420 patients were treated with ICIs for advanced HCC after one line of systemic therapy (n = 371, 88.8%): 31 (8.8%) had died, 152 (36.2%) received best supportive care (BSC) following ICIs, and 163 patients (38.8%) received subsequent anticancer therapy. Tyrosine kinase inhibitors (TKIs, n = 132, 80.9%), in particular sorafenib (n = 49, 30.0%), were the most common post-ICI therapy followed by external beam radiotherapy (n = 28, 17.2%), further immunotherapy (n = 21, 12.9%), locoregional therapy (n = 23, 14.1%), chemotherapy (n = 9, 5.5%), and surgery (n = 6, 3.6%). Receipt of post-ICI therapy was associated with longer median OS compared with those who had received BSC (12.1 vs. 3.3 months; hazard ratio [HR]: 0.4 (95% CI: 2.7-5.0). No difference in OS was noted in those patients who received TKI before ICIs compared with those who received ICIs followed by TKI. Conclusion: Post-ICI therapy is associated with OS in excess of 12 months, suggesting a role for therapeutic sequencing. OS from TKI therapy was similar to that reported in registration studies, suggesting preserved efficacy following ICIs.

Combined PD-1/VEGFR Blockade: A New Era of Treatment for Hepatocellular Cancer.

Combination immunotherapy is an expanding therapeutic modality in hepatocellular carcinoma (HCC), a disease where single-agent immunotherapy has failed to lead to survival benefit. The RESCUE trial adds camrelizumab and apatinib to the therapeutic armamentarium of advanced HCC, raising questions around the optimal positioning of various combination regimens in liver cancer.See related article by Xu et al., p. 1003.

Phenotypic Characteristics of the Tumour Microenvironment in Primary and Secondary Hepatocellular Carcinoma.

(1) Background: The intra-tumoural heterogeneity (ITH) of hepatocellular carcinoma (HCC) and its microenvironment (TME) across primary and secondary disease is poorly characterised. (2) Methods: Intra-tumoural (IT) and peri-tumoural (PT) staining of matched primary and secondary samples was conducted to evaluate the distribution of CD4+/FOXP3+ and CD8+/PD1+ T-cells. Samples underwent PD-L1/2 immunostaining, tumour mutational burden (TMB) evaluation, and high-resolution T-cell receptor (TCR) sequencing to derive T-cell clonality and targeted transcriptomics. (3) Results: We analysed 24 samples from matched primary (n = 11) and secondary (n = 13; 5 synchronous, 6 metachronous) deposits, 11 being extrahepatic (84.6%). IT CD8+ density was lower than PT in both primary (p = 0.005) and secondary deposits (p = 0.01), consistent with immune exclusion. PD-L1+ tumours displayed higher IT and PT CD8+/PD1+ cell density compared to PD-L1- (p < 0.05), and primary IT infiltrate was enriched in CD4+/FOXP3+ cells, compared to PT regions (p = 0.004). TCR-sequencing demonstrated enrichment of the top T-cell clonotype in secondary versus primary HCC (p = 0.02), without differences in overall productive clonality (p = 0.35). TMB was similar across primary versus secondary HCC (p = 0.95). While directed gene set analysis demonstrated the uniformity of transcriptional signatures of individual immune cell types, secondary deposits demonstrated higher COLEC12 (p = 0.004), CCL26 (p = 0.02), CD1E (p = 0.02) and CD36 (p = 0.03) expression with downregulation of CXCL1 (p = 0.03), suggesting differential regulation of innate immunity. (4) Conclusion: Immune exclusion is a defining feature of the HCC TME. Despite evidence of homogeneity in somatic TMB, secondary HCC is characterised by the expansion of a distinct T-cell clonotype and differential regulation of innate immune pathways.

Antacid exposure and immunotherapy outcomes among patients with advanced hepatocellular carcinoma.

BACKGROUND: Antibiotic exposure has been associated with worse outcomes with immune checkpoint inhibitors (ICIs) in cancer patients, likely due to disruption of the gut microbiome. Other commonly prescribed medications, such as proton pump inhibitors (PPIs) and histamine-2-receptor antagonists (H2RAs), are also known to disrupt the microbiome, but data on their association with ICI outcomes are conflicting. METHODS: We conducted a retrospective, multicenter, international cohort study including 314 hepatocellular carcinoma (HCC) patients treated with ICIs from 2017 to 2019 to assess the association between PPI or H2RA exposure (up to 30 days before ICI) and overall survival. Secondary outcomes included overall response rate (ORR) and development of any treatment-related adverse events (AEs). RESULTS: Baseline PPI/H2RA exposure was not associated with overall survival in univariable (HR 1.01, 95% CI 0.75-1.35) or multivariable analysis (HR 0.98, 95% CI 0.71-1.36). Baseline PPI/H2RA exposure was not associated with either ORR (OR 1.32, 95% CI 0.66-2.65) or AEs (OR 1.07, 95% CI 0.54-2.12) in multivariable analysis. CONCLUSIONS: Our results suggest that exposure to PPI/H2RA prior to ICIs does not adversely affect outcomes in HCC patients.

Trans-arterial chemoembolization as a loco-regional inducer of immunogenic cell death in hepatocellular carcinoma: implications for immunotherapy.

BACKGROUND: Modulation of adaptive immunity may underscore the efficacy of trans-arterial chemoembolization (TACE). We evaluated the influence of TACE on T-cell function by phenotypic lymphocyte characterization in samples of patients undergoing surgery with (T+) or without (T-) prior-TACE treatment. METHODS: We profiled intratumoral (IT), peritumoral (PT) and non-tumoral (NT) background tissue to evaluate regulatory CD4+/FOXP3+ (T-reg) and immune-exhausted CD8+/PD-1+ T-cells across T+ (n=58) and T- (n=61). We performed targeted transcriptomics and T-cell receptor sequencing in a restricted subset of samples (n=24) evaluated in relationship with the expression of actionable drivers of anti-cancer immunity including PD-L1, indoleamine 2,3 dehydrogenase (IDO-1), cytotoxic T-lymphocyte associated protein 4 (CTLA-4), Lag-3, Tim-3 and CD163. RESULTS: We analyzed 119 patients resected (n=25, 21%) or transplanted (n=94, 79%) for Child-Pugh A (n=65, 55%) and Barcelona Clinic Liver Cancer stage A (n=92, 77%) hepatocellular carcinoma. T+ samples displayed lower IT CD4+/FOXP3+ (p=0.006), CD8+ (p=0.002) and CD8+/PD-1+ and NT CD8+/PD-1+ (p<0.001) compared with T-. Lower IT (p=0.005) and NT CD4+/FOXP3+ (p=0.03) predicted for improved recurrence-free survival. In a subset of samples (n=24), transcriptomic analysis revealed upregulation of a pro-inflammatory response in T+. T+ samples were enriched for IRF2 expression (p=0.01), an interferon-regulated transcription factor implicated in cancer immune-evasion. T-cell clonality and expression of PD-L1, IDO-1, CTLA-4, Lag-3, Tim-3 and CD163 was similar in T+ versus T-. CONCLUSIONS: TACE is associated with lower IT density of immune-exhausted effector cytotoxic and T-regs, with significant upregulation of pro-inflammatory pathways. This highlights the pleiotropic effects of TACE in modulating the tumor microenvironment and strengthens the rationale for developing immunotherapy alongside TACE.

Early Antibiotic Exposure Is Not Detrimental to Therapeutic Effect from Immunotherapy in Hepatocellular Carcinoma.

BACKGROUND AND RATIONALE: Immune checkpoint inhibitor (ICI) therapy is an expanding therapeutic option for hepatocellular carcinoma (HCC). Antibiotics (ATB) taken prior to or early during ICI therapy can impact immunotherapy efficacy across indications; however, the effect of ATB is undefined in HCC. METHODS: In a large international cohort of 450 ICI recipients from Europe, North America, and Asia, we categorized patients according to timing of ATB focusing on exposure within -30 to +30 days from ICI (early immunotherapy period [EIOP]). EIOP was evaluated in association with overall survival (OS), progression-free survival (PFS), and best radiologic response using RECIST 1.1 criteria. RESULTS: Our study comprised mostly cirrhotic (329, 73.3%) males (355, 79.1%) with a Child-Turcotte Pugh class of A (332, 73.9%), receiving ICI after 1 therapy line (251, 55.9%) for HCC of Barcelona clinic liver cancer stage C (325, 72.4%). EIOP (n = 170, 37.9%) was independent of baseline clinicopathologic features of HCC and correlated with longer PFS (6.1 vs. 3.7 months, log-rank p = 0.0135). EIOP+ patients had similar OS, overall response, and disease control rates (DCRs) compared to EIOP. The effect of EIOP persisted in landmark time analyses and in multivariable models, confirming the independent predictive role of EIOP in influencing PFS following adjustment for covariates reflective of tumor burden, liver function, and ICI regimen administered. In patients receiving programmed cell death-1 receptor/ligand inhibitors monotherapy, EIOP was also associated with higher DCRs (61.4% vs. 50.9%, p = 0.0494). CONCLUSIONS: Unlike other oncological indications, ATB in the 30 days before or after ICI initiation is associated with improved benefit from immunotherapy, independent of disease and treatment-related features. Evaluation of the immune microbiologic determinants of response to ICI in HCC warrants further investigation.

Immune-based therapies for hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third most frequent cause of cancer-related death. The immune-rich contexture of the HCC microenvironment makes this tumour an appealing target for immune-based therapies. Here, we discuss how the functional characteristics of the liver microenvironment can potentially be harnessed for the treatment of HCC. We will review the evidence supporting a therapeutic role for vaccines, cell-based therapies and immune-checkpoint inhibitors and discuss the potential for patient stratification in an attempt to overcome the series of failures that has characterised drug development in this disease area.

Post-registration experience of nivolumab in advanced hepatocellular carcinoma: an international study.

BACKGROUND: Nivolumab is Food and Drug Administration approved in sorafenib-experienced, advanced hepatocellular carcinoma (HCC). Post-registration data of treatment in a real-world setting is lacking. PATIENTS AND METHODS: We performed an international, multicenter observational study to confirm safety and efficacy of nivolumab in 233 patients treated outside clinical trials from eight centers in North America, Europe and Asia. RESULTS: Patients received nivolumab for Barcelona Clinic Liver Cancer stage C (n=191, 92.0%) and Child-Pugh (CP) A (n=158, 67.8%) or B (n=75, 32.2%) HCC as first (n=85, 36.5%) or second to fourth systemic therapy line (n=148, 63.5%). Objective response rate (ORR) was 22.4% and disease control rate was 52.1%. Median overall survival (OS) was 12.2 months (95% CI 8.4 to 16.0) and median progression-free survival was 10.1 months (95% CI 6.1 to 14.2). Treatment-related adverse events of grade >2 occurred in 26 patients (11.2%). Efficacy and safety were similar across CP classes and therapy line. OS was shorter in CP-B than A (7.3 months vs 16.3 months, p<0.001) and in post-first line use (10.4 months vs 16.3 months, p=0.05). Achievement of an objective response predicted for improved OS (25.4 months vs 13.2 months, p<0.001). CONCLUSIONS: This study confirms safety and efficacy of nivolumab in advanced HCC across various lines of therapy and degrees of liver dysfunction. Despite equal ORR and toxicity to nivolumab, patients with CP-B functional class have shorter survival than the patients with CP-A.

Impact of corticosteroid therapy on the outcomes of hepatocellular carcinoma treated with immune checkpoint inhibitor therapy.

The impact of corticosteroid therapy (CT) on efficacy of immune checkpoint inhibitors (ICI) is undefined in hepatocellular carcinoma (HCC). We evaluated whether CT administered at baseline (bCT) or concurrently with ICI (cCT) influences overall (OS), progression-free survival (PFS) and overall response rates (ORR) in 341 patients collected across 3 continents. Of 304 eligible patients, 78 (26%) received >10 mg prednisone equivalent daily either as bCT (n=14, 5%) or cCT (n=64, 21%). Indications for CT included procedure/prophylaxis (n=37, 47%), management of immune-related adverse event (n=27, 35%), cancer-related symptoms (n=8, 10%) or comorbidities (n=6, 8%). Neither overall CT, bCT nor cCT predicted for worse OS, PFS nor ORR in univariable and multivariable analyses (p>0.05). CT for cancer-related indications predicted for shorter PFS (p<0.001) and was associated with refractoriness to ICI (75% vs 33%, p=0.05) compared with cancer-unrelated indications. This is the first study to demonstrate that neither bCT nor cCT influence response and OS following ICI in HCC. Worse outcomes in CT recipients for cancer-related indications appear driven by the poor prognosis associated with symptomatic HCC.

Evaluation of the sensitivity of R1ρ MRI to pH and macromolecular density.

The tumor microenvironment is characteristically acidic and this extracellular acidosis is known to play a role in carcinogenesis and metastasis and can affect tumor chemosensitivity and radiosensitivity. Intracellular pH has been used as a possible biomarker of salvageable tissue in ischemic stroke. A non-invasive MRI-based approach for the determination and imaging of cerebral pH would be a powerful tool in cancer diagnosis and monitoring, as well as stroke treatment planning. Several pH-based MRI imaging approaches have been proposed but for these to be useful, disentangling the effects of pH from other parameters which may affect the measured MRI signal is crucial to ensure accuracy and specificity. R1 relaxation in the rotating frame (R1ρ) is an example of a method that has been proposed to probe pH in vivo using MRI. In this study, we have investigated the relationship between R1ρ, pH, and macromolecular density in vitro using phantoms and in human volunteers. Here we show that the rate of R1ρ relaxation (=1/T1ρ) varies with pH but only in the presence of macromolecules. At constant pH, phantom macromolecular density inversely correlated with R1ρ. R1ρ imaging of the normal human brain demonstrated regional heterogeneity with significant differences between structurally distinct regions, which are likely to be independent of pH. For example, R1ρ was higher in the basal ganglia compared to grey matter and higher in grey matter compared to white matter. We conclude that R1ρ cannot be reliably used to image tissue pH without deconvolution from the effects of local tissue macromolecular composition.

A molecular and preclinical comparison of the PD-1-targeted T-cell checkpoint inhibitors nivolumab and pembrolizumab.

T-cell checkpoint inhibition has a profound impact on cancer care and the programmed cell death protein 1 (PD-1)-targeted antibodies nivolumab and pembrolizumab have been two of the lead molecules of this therapeutic revolution. Their clinical comparability is a highly relevant topic of discussion, but to a significant degree is a consequence of their molecular properties. Here we provide a molecular, preclinical, and early clinical comparison of the two antibodies, based on the available data and recent literature. We acknowledge the limitations of such comparisons, but suggest that based on the available data, differences in clinical trial outcomes between nivolumab and pembrolizumab are more likely drug-independent than drug-dependent.

Risk stratification of Barrett's oesophagus using a non-endoscopic sampling method coupled with a biomarker panel: a cohort study.

BACKGROUND: Barrett's oesophagus predisposes to adenocarcinoma. However, most patients with Barrett's oesophagus will not progress and endoscopic surveillance is invasive, expensive, and fraught by issues of sampling bias and the subjective assessment of dysplasia. We investigated whether a non-endoscopic device, the Cytosponge, could be coupled with clinical and molecular biomarkers to identify a group of patients with low risk of progression suitable for non-endoscopic follow-up. METHODS: In this multicentre cohort study (BEST2), patients with Barrett's oesophagus underwent the Cytosponge test before their surveillance endoscopy. We collected clinical and demographic data and tested Cytosponge samples for a molecular biomarker panel including three protein biomarkers (P53, c-Myc, and Aurora kinase A), two methylation markers (MYOD1 and RUNX3), glandular atypia, and TP53 mutation status. We used a multivariable logistic regression model to compute the conditional probability of dysplasia status. We selected a simple model with high classification accuracy and applied it to an independent validation cohort. The BEST2 study is registered with ISRCTN, number 12730505. FINDINGS: The discovery cohort consisted of 468 patients with Barrett's oesophagus and intestinal metaplasia. Of these, 376 had no dysplasia and 22 had high-grade dysplasia or intramucosal adenocarcinoma. In the discovery cohort, a model with high classification accuracy consisted of glandular atypia, P53 abnormality, and Aurora kinase A positivity, and the interaction of age, waist-to-hip ratio, and length of the Barrett's oesophagus segment. 162 (35%) of 468 of patients fell into the low-risk category and the probability of being a true non-dysplastic patient was 100% (99% CI 96-100) and the probability of having high-grade dysplasia or intramucosal adenocarcinoma was 0% (0-4). 238 (51%) of participants were classified as of moderate risk; the probability of having high-grade dysplasia was 14% (9-21). 58 (12%) of participants were classified as high-risk; the probability of having non-dysplastic endoscopic biopsies was 13% (5-27), whereas the probability of having high-grade dysplasia or intramucosal adenocarcinoma was 87% (73-95). In the validation cohort (65 patients), 51 were non-dysplastic and 14 had high-grade dysplasia. In this cohort, 25 (38%) of 65 patients were classified as being low-risk, and the probability of being non-dysplastic was 96·0% (99% CI 73·80-99·99). The moderate-risk group comprised 27 non-dysplastic and eight high-grade dysplasia cases, whereas the high-risk group (8% of the cohort) had no non-dysplastic cases and five patients with high-grade dysplasia. INTERPRETATION: A combination of biomarker assays from a single Cytosponge sample can be used to determine a group of patients at low risk of progression, for whom endoscopy could be avoided. This strategy could help to avoid overdiagnosis and overtreatment in patients with Barrett's oesophagus. FUNDING: Cancer Research UK.