Shifts in internal stem damage along a tropical precipitation gradient and implications for forest biomass estimation

Woody biomass is a large carbon store in terrestrial ecosystems. In calculating biomass, tree stems are assumed to be solid structures. However, decomposer agents such as microbes and insects target stem heartwood, causing internal wood decay which is poorly quantified. We investigated internal stem damage across five sites in tropical Australia along a precipitation gradient. We estimated the amount of internal aboveground biomass damaged in living trees and measured four potential stem damage predictors: wood density, stem diameter, annual precipitation, and termite pressure (measured as termite damage in downed deadwood). Stem damage increased with increasing diameter, wood density, and termite pressure and decreased with increasing precipitation. High wood density stems sustained less damage in wet sites and more damage in dry sites, likely a result of shifting decomposer communities and their differing responses to changes in tree species and wood traits across sites. Incorporating stem damage reduced aboveground biomass estimates by > 30% in Australian savannas, compared to only 3% in rainforests. Accurate estimates of carbon storage across woody plant communities are critical for understanding the global carbon budget. Future biomass estimates should consider stem damage in concert with the effects of changes in decomposer communities and abiotic conditions.

Robotic Anatomical Pulmonary Resections: An Australian Experience

BACKGROUND

Robotic thoracic surgery is a minimally invasive technique that allows the surgeon to perform delicate, accurate surgical manoeuvres within the chest cavity without rib spreading. Previous studies have suggested potential benefits of the robotic platform in nodal upstaging due to its versatility, seven degrees of freedom of movement, and superior vision. However, there is currently a paucity of robust clinical data from Australia.

AIMS

This study aimed to assess the perioperative safety and oncological efficacy of anatomical pulmonary resections performed using the robotic platform. Endpoints included mortality and major morbidity outcomes according to Clavien-Dindo classification and rate of pathological nodal upstaging compared with preoperative imaging using positron emission tomography.

METHODS

A single-surgeon retrospective analysis was performed using data collected from two institutions from July 2021 to May 2022, after ethics committee approval. Consecutive patients who underwent anatomical robotic resections were included in the study, with subsequent analysis of patients who had confirmed primary lung cancer.

RESULTS

A total of 52 patients underwent robotic anatomical pulmonary resection during the study period. Safety was demonstrated by 0% mortality and a 9.6% major complication rate, which was related to chest tube insertion for prolonged air leak or intensive care unit monitoring during treatment of atrial arrhythmia. After excluding patients who did not have primary lung cancer, 48 patients remained for further analysis; pathological nodal upstaging was observed in nine (18.8%) of these patients. On multivariate analysis, the total number of lymph nodes harvested was found to be a statistically significant predictor of nodal upstaging. Complete microscopic resection (R0) was achieved in 100% of patients.

CONCLUSIONS

This study represents the most extensive documentation of robotic thoracic procedures in Australia in the existing literature. It demonstrated a satisfactory safety profile with a relatively high rate of nodal upstaging, possibly reflecting the ability of the robotic instruments to perform comprehensive and complete nodal resection at the time of anatomical pulmonary resection.

KRAS and BRAF Mutation Rates and Survival Outcomes in Colorectal Cancer in an Ethnically Diverse Patient Cohort

KRAS and BRAF mutation rates in colorectal cancer (CRC) reported from various mono-ethnic studies vary amongst different ethnic groups. However, these differences in mutation rates may not be statistically significant or may be due to differences in environmental and/or laboratory factors across countries rather than racial genetic differences. Here, we compare the KRAS/BRAF mutation rates and survival outcomes in CRC between ethnic groups at a single institution. We also investigate the contributions of genetic, environmental, and laboratory factors to the variations in KRAS/BRAF mutation rates reported from different countries. Clinicopathological data from 453 ethnically diverse patients with CRC were retrospectively analyzed at Liverpool Hospital, NSW Australia (2014-2016). KRAS/BRAF mutations were detected using real-time PCR (Therascreen kits from Qiagen). Mismatch repair (MMR) status was determined using immunohistochemical staining. Four ethnic groups were analyzed: Caucasian, Middle Eastern, Asian, and South American. Overall survival data were available for 406 patients. There was no significant difference in KRAS mutation rates between Caucasians (41.1%), Middle Easterners (47.9%), Asians (44.8%), and South Americans (25%) (p = 0.34). BRAF mutation rates differed significantly between races (p = 0.025), with Caucasians having the highest rates (13.5%) and Middle Easterners the lowest (0%). A secondary analysis in which Caucasians were divided into three subgroups showed that ethnic grouping correlated significantly with KRAS mutation rate (p = 0.009), with central and eastern Europeans having the highest rates (58.3%). There were no significant differences in overall survival (OS) or disease-free survival (DFS) between the four races. The similarity in KRAS mutation rates across races raises the possibility that the differences in KRAS mutation rates reported from various countries may either not be statistically significant or may be due to environmental and/or laboratory factors rather than underlying racial genetic differences. In contrast, we verified that BRAF mutation rates differ significantly between races, suggesting racial genetic differences may be responsible for the discrepant BRAF mutation rates reported from different countries.

Real-world prevalence of PD-L1 expression in non-small cell lung cancer: an Australia-wide multi-centre retrospective observational study

An investigator-initiated, Australia-wide multi-centre retrospective observational study was undertaken to investigate the real-world prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC). Multiple centres around Australia performing PD-L1 immunohistochemistry (IHC) were invited to participate. Histologically confirmed NSCLC of any stage with a PD-L1 IHC test performed for persons aged ≥18 years between 1 January 2018 and 1 January 2020, and eligible for review, were identified at each centre, followed by data extraction and de-identification, after which data were submitted to a central site for collation and analysis. In total data from 6690 eligible PD-L1 IHC tests from histologically (75%) or cytologically (24%) confirmed NSCLC of any stage were reviewed from persons with a median age of 70 years, 43% of which were female. The majority (81%) of tests were performed using the PD-L1 IHC SP263 antibody with the Ventana BenchMark Ultra platform and 19% were performed using Dako PD-L1 IHC 22C3 pharmDx assay. Reported PD-L1 tumour proportion score (TPS) was ≥50% for 30% of all tests, with 62% and 38% scoring PD-L1 ≥1% and <1%, respectively. Relative prevalence of clinicopathological features with PD-L1 scores dichotomised to <50% and ≥50%, or to <1% and ≥1%, were examined. Females scored ≥1% slightly more often than males (64% vs 61%, respectively, p=0.013). However, there was no difference between sexes or age groups (<70 or ≥70 years) where PD-L1 scored ≥50%. Specimens from patients with higher stage (III/IV) scored ≥1% or ≥50% marginally more often compared to specimens from patients with lower stage (I/II) (p≤0.002). Proportions of primary and metastatic specimens did not differ where PD-L1 TPS was ≥1%, however more metastatic samples scored TPS ≥50% than primary samples (metastatic vs primary; 34% vs 27%, p<0.001). Cytology and biopsy specimens were equally reported, at 63% of specimens, to score TPS ≥1%, whereas cytology samples scored TPS ≥50% slightly more often than biopsy samples (34% vs 30%, respectively, p=0.004). Resection specimens (16% of samples tested) were reported to score TPS ≥50% or ≥1% less often than either biopsy or cytology samples (p<0.001). There was no difference in the proportion of tests with TPS ≥1% between PD-L1 IHC assays used, however the proportion of tests scored at TPS ≥50% was marginally higher for 22C3 compared to SP263 (34% vs 29%, respectively, p<0.001). These real-world Australian data are comparable to some previously published global real-world data, with some differences noted.

Defining Morphologic Features of Invasion in Pulmonary Nonmucinous Adenocarcinoma With Lepidic Growth: A Proposal by the International Association for the Study of Lung Cancer Pathology Committee

INTRODUCTION

Since the eight edition of the Union for International Cancer Control and American Joint Committee on Cancer TNM classification system, the primary tumor pT stage is determined on the basis of presence and size of the invasive components. The aim of this study was to identify histologic features in tumors with lepidic growth pattern which may be used to establish criteria for distinguishing invasive from noninvasive areas.

METHODS

A Delphi approach was used with two rounds of blinded anonymized analysis of resected nonmucinous lung adenocarcinoma cases with presumed invasive and noninvasive components, followed by one round of reviewer de-anonymized and unblinded review of cases with known outcomes. A digital pathology platform was used for measuring total tumor size and invasive tumor size.

RESULTS

The mean coefficient of variation for measuring total tumor size and tumor invasive size was 6.9% (range: 1.7%-22.3%) and 54% (range: 14.7%-155%), respectively, with substantial variations in interpretation of the size and location of invasion among pathologists. Following the presentation of the results and further discussion among members at large of the International Association for the Study of Lung Cancer Pathology Committee, extensive epithelial proliferation (EEP) in areas of collapsed lepidic growth pattern is recognized as a feature likely to be associated with invasive growth. The EEP is characterized by multilayered luminal epithelial cell growth, usually with high-grade cytologic features in several alveolar spaces.

CONCLUSIONS

Collapsed alveoli and transition zones with EEP were identified by the Delphi process as morphologic features that were a source of interobserver variability. Definition criteria for collapse and EEP are proposed to improve reproducibility of invasion measurement.

Predictive Biomarkers for Immunotherapy in Lung Cancer: Perspective From the International Association for the Study of Lung Cancer Pathology Committee

Immunotherapy including immune checkpoint inhibitors (ICIs) has become the backbone of treatment for most lung cancers with advanced or metastatic disease. In addition, they have increasingly been used for early stage tumors in neoadjuvant and adjuvant settings. Unfortunately, however, only a subset of patients experiences meaningful response to ICIs. Although programmed death-ligand 1 (PD-L1) protein expression by immunohistochemistry (IHC) has played a role as the principal predictive biomarker for immunotherapy, its performance may not be optimal, and it suffers multiple practical issues with different companion diagnostic assays approved. Similarly, tumor mutational burden (TMB) has multiple technical issues as a predictive biomarker for ICIs. Now, ongoing research on tumor- and host immune-specific factors has identified immunotherapy biomarkers that may provide better response and prognosis prediction, in particular in a multimodal approach. This review by the International Association for the Study of Lung Cancer Pathology Committee provides an overview of various immunotherapy biomarkers, including updated data on PD-L1 IHC and TMB, and assessments of neoantigens, genetic and epigenetic signatures, immune microenvironment by IHC and transcriptomics, and microbiome and pathologic response to neoadjuvant immunotherapies. The aim of this review is to underline the efficacy of new individual or combined predictive biomarkers beyond PD-L1 IHC and TMB.

Abstract 5963: A framework for extrapolating evidence for molecularly targeted therapies from common to rare cancers - bridging the gap

BACKGROUND: Advances in understanding of potentially targetable molecular pathways driving carcinogenesis coupled with rapid development of tumor profiling technologies are partitioning cancers into rare biomarker-defined diseases. Assessing biomarker-targeted therapies within these small populations in adequately powered randomized trials is becoming unfeasible, leading to reliance on lower quality evidence from uncontrolled studies using unvalidated surrogate outcomes. When robust evidence for a targeted therapy being considered already exists in common cancers, this evidence may potentially be extrapolated to support the use of this therapy in rare cancers sharing the same biomarker and reduce additional evidence requirements for regulatory or reimbursement approval. However, extrapolation may not be appropriate in some settings due to biological differences between cancer types.

METHODS: Building on recommendations for core components of extrapolation identified from a scoping review of methodological guidance, we constructed a framework proposing criteria for extrapolating evidence for targeted therapies from common to rare cancers.

RESULTS: Criteria reflect key assumptions of disease similarity when defined by the biomarker and similarity of treatment response. Criteria are judged under five extrapolation components: (1) Analytical validity of the test used to identify the biomarker and criteria used to define biomarker status in the rare cancer, (2) Strength of evidence supporting biomarker actionability in the rare cancer and evidence that actionability may differ from the common cancer, (3) Quantitative estimation of the natural history of the biomarker-defined rare cancer as control group, (4) Validity of surrogate endpoints used to extrapolate treatment effect from the common cancer and predictions of clinical benefit in the rare cancer, and (5) Similarity of the safety profile between cancers and methods to augment safety data in the rare cancer. Using these criteria, decision-makers can judge whether sufficient evidence exists to support extrapolation or identify specific knowledge gaps to better target further research to be able to judge whether extrapolation is appropriate or not. Residual uncertainties for fulfilling criteria can also define post-approval commitments.

CONCLUSIONS: We outline a pragmatic and systematic approach for selecting and evaluating existing evidence to judge when extrapolation is appropriate. This framework can be used to promote standardized, comprehensive, and transparent decision-making and facilitate discussion between stakeholders in drug development and clinical guideline and health technology assessment groups.

Citation Format: Doah Cho, Sarah J. Lord, John R. Simes, Wendy Cooper, Saskia Cheyne, Chee Khoon Lee. A framework for extrapolating evidence for molecularly targeted therapies from common to rare cancers - bridging the gap [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5963.

Residual ctDNA after treatment predicts early relapse in patients with early-stage non-small cell lung cancer

BACKGROUND

Identification of residual disease in patients with localized non-small cell lung cancer (NSCLC) following treatment with curative intent holds promise to identify patients at risk of relapse. New methods can detect circulating tumour DNA (ctDNA) in plasma to fractional concentrations as low as a few parts per million, and clinical evidence is required to inform their use.

PATIENTS AND METHODS

We analyzed 363 serial plasma samples from 88 patients with early-stage NSCLC (48.9%/28.4%/22.7% at stage I/II/III), predominantly adenocarcinomas (62.5%), treated with curative intent by surgery (n = 61), surgery and adjuvant chemotherapy/radiotherapy (n = 8), or chemoradiotherapy (n = 19). Tumour exome sequencing identified somatic mutations and plasma was analyzed using patient-specific RaDaR™ assays with up to 48 amplicons targeting tumour-specific variants unique to each patient.

RESULTS

ctDNA was detected before treatment in 24%, 77% and 87% of patients with stage I, II and III disease, respectively, and in 26% of all longitudinal samples. The median tumour fraction detected was 0.042%, with 63% of samples <0.1% and 36% of samples <0.01%. ctDNA detection had clinical specificity >98.5% and preceded clinical detection of recurrence of the primary tumour by a median of 212.5 days. ctDNA was detected after treatment in 18/28 (64.3%) of patients who had clinical recurrence of their primary tumour. Detection within the landmark timepoint 2 weeks to 4 months after treatment end occurred in 17% of patients, and was associated with shorter recurrence-free survival [hazard ratio (HR): 14.8, P <0.00001] and overall survival (HR: 5.48, P <0.0003). ctDNA was detected 1-3 days after surgery in 25% of patients yet was not associated with disease recurrence. Detection before treatment was associated with shorter overall survival and recurrence-free survival (HR: 2.97 and 3.14, P values 0.01 and 0.003, respectively).

CONCLUSIONS

ctDNA detection after initial treatment of patients with early-stage NSCLC using sensitive patient-specific assays has potential to identify patients who may benefit from further therapeutic intervention.

Fulminant Delta COVID-19 myocarditis: a case report of fatal primary cardiac dysfunction

Background

Whilst myocarditis or myocardial injury due to severe acute respiratory syndrome coronavirus 2 infection is commonly reported, profound primary cardiac dysfunction requiring mechanical circulatory support, with the development of fulminant myocarditis prior to respiratory failure, is rarely described. The endomyocardial biopsy (EMB) findings in these patients is seldom reported, the findings are varied, and effective treatment unknown.

Case summary

A 39-year-old female with no significant past medical history and confirmed Delta variant coronavirus disease 2019 (COVID-19) infection (Day 3), presented with a 1 day history of diarrhoea, vomiting, and abdominal pain. The patient denied respiratory symptoms and chest X-ray was clear. Lactate level was 6.3, initial troponin T 118 ng/L. Despite resuscitation, the patient significantly deteriorated in the emergency department, resulting in pulseless electrical activity arrest requiring veno-arterial extra-corporeal membrane oxygenation cardiopulmonary resuscitation. Over the following 36 h, cardiac function deteriorated to near-complete left ventricular (LV) standstill. Coronary angiography revealed normal coronary arteries with slow flow. Endomyocardial biopsy showed diffuse interstitial macrophage infiltrate and small vessel thromboses. Left ventricular function did not improve over the following 7 days, and despite treatment with tocilizumab, high-dose steroids, and intravenous immunoglobulin, she eventually died due to disease-related complications.

Discussion

Primary cardiac dysfunction secondary to COVID-19 infection is rarely reported. Little is known about the incidence, natural history, and pathophysiology of fulminant COVID-19 myocarditis. We present the most severe case of cardiac dysfunction due to COVID-19 reported in a young patient without respiratory compromise who never recovered from any cardiac function.

Next-generation sequencing, should I use anti-HER2 therapy for HER2-amplified tumors off-label? Illustrating an extrapolation framework

Background:

Next-generation sequencing is used to increase targeted treatment opportunities, particularly for patients who have exhausted standard options. Where randomized controlled trial evidence for a targeted therapy is available for molecular alterations in one tumor type, the dilemma for the clinician is whether ‘matching’ targeted agents should be recommended off-label for the same molecular alterations detected in other tumor types, for which no trial data are available to guide practice. To judge the likely benefits, it may be possible to extrapolate evidence from cancers where treatment benefits have been established.

Methods:

We present a framework for assessing the appropriateness of extrapolation using trastuzumab, an anti-HER2 antibody, for HER2-amplified tumors where trastuzumab use would be off-label as an illustrative example.

Results:

The following should be considered for the tumor type where trastuzumab would be off-label: (a) reliability of the NGS assay for detecting HER2 amplification; (b) criteria for defining HER2 positivity; (c) strength of evidence supporting the actionability of HER2 amplification and trastuzumab; (d) whether better clinical outcomes with trastuzumab are due to a more favorable natural history rather than trastuzumab effect; (e) signals of trastuzumab activity and whether it translates to clinically meaningful benefit; (f) whether the safety profile of trastuzumab differs from established indications; and (g) discussion points for shared decision making (SDM) to facilitate informed consent.

Conclusion:

We present a systematic approach for appraising evidence to support extrapolating trastuzumab benefits from established indications to off-label applications. Extrapolation criteria and areas of uncertainty to inform SDM are outlined. This framework is potentially generalizable to other tumor-agnostic biomarker-targeted therapy scenarios. It is a practical approach for clinicians to apply in routine practice and should be considered by molecular tumor boards who make off-label recommendations.

Fragmentation patterns and personalized sequencing of cell-free DNA in urine and plasma of glioma patients

Glioma-derived cell-free DNA (cfDNA) is challenging to detect using liquid biopsy because quantities in body fluids are low. We determined the glioma-derived DNA fraction in cerebrospinal fluid (CSF), plasma, and urine samples from patients using sequencing of personalized capture panels guided by analysis of matched tumor biopsies. By sequencing cfDNA across thousands of mutations, identified individually in each patient's tumor, we detected tumor-derived DNA in the majority of CSF (7/8), plasma (10/12), and urine samples (10/16), with a median tumor fraction of 6.4 × 10-3 , 3.1 × 10-5 , and 4.7 × 10-5 , respectively. We identified a shift in the size distribution of tumor-derived cfDNA fragments in these body fluids. We further analyzed cfDNA fragment sizes using whole-genome sequencing, in urine samples from 35 glioma patients, 27 individuals with non-malignant brain disorders, and 26 healthy individuals. cfDNA in urine of glioma patients was significantly more fragmented compared to urine from patients with non-malignant brain disorders (P = 1.7 × 10-2 ) and healthy individuals (P = 5.2 × 10-9 ). Machine learning models integrating fragment length could differentiate urine samples from glioma patients (AUC = 0.80-0.91) suggesting possibilities for truly non-invasive cancer detection.

Disseminated intravascular coagulation complicating diagnosis of ROS1-mutant non-small cell lung cancer: A case report and literature review

Disseminated intravascular coagulation (DIC) is a rare paraneoplastic complication in advanced solid malignancies, with success of treatment and survival dependent on treatment of the underlying malignancy. Best estimates suggest an incidence of 1.6–6.8% in cancer, with risk factors being advanced disease, older age, and adenocarcinoma, especially of lung origin. Few cases, however, have reported on an association between DIC and oncogene‐addicted lung cancers, especially those containing ROS proto‐oncogene 1 (ROS1) mutations, however precedent exists to suggest increased prothrombotic rates in tumors harboring this mutation. We present a young woman with ROS1‐mutant non‐small‐cell lung cancer who presented in DIC and subsequently developed complications of both hemorrhage and thrombosis. Following initiation of targeted treatment, rapid resolution of laboratory coagulation derangement was observed and clinical improvement quickly followed. This event underscores the need for rapid evaluation of lung molecular panels and the dramatic resolution of life‐threatening illness that can occur with institution of appropriate therapy. This case contributes to growing evidence for a possible underlying link between oncogene addicted tumors and abnormalities of coagulation.

Primary membranous glomerulonephritis with negative serum PLA2R in haemophilia A successfully managed with rituximab - case report and review of the literature

BACKGROUND

Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) cause a wide range of glomerular pathologies. In people with haemophilia, transfusion-associated infections with these viruses are common and definitive pathological diagnosis in this population is complicated by the difficulty of safely obtaining a renal biopsy. Membranous nephropathy (MN) is a common cause of adult onset nephrotic syndrome occurring in both primary and secondary forms. Primary MN is associated with podocyte autoantibodies, predominantly against phospholipase A2 receptor (PLA2R). Secondary disease is often associated with viral infection; however, infrequently with HIV or HCV. Distinguishing these entities from each other and other viral glomerular disease is vital as treatment strategies are disparate.

CASE PRESENTATION

We present the case of a 48-year-old man with moderate haemophilia A and well-controlled transfusion-associated HCV and HIV coinfection who presented with sudden onset nephrotic range proteinuria. Renal biopsy demonstrated grade two membranous nephropathy with associated negative serum PLA2R testing. Light and electron microscopic appearances were indeterminant of a primary or secondary cause. Given his extremely stable co-morbidities, treatment with rituximab and subsequent angiotensin receptor blockade was initiated for suspected primary MN and the patient had sustained resolution in proteinuria over the following 18 months. Subsequent testing demonstrated PLA2R positive glomerular immunohistochemistry despite multiple negative serum results.

CONCLUSIONS

Pursuing histological diagnosis is important in complex cases of MN as the treatment strategies between primary and secondary vary significantly. Serum PLA2R testing alone may be insufficient in the presence of multiple potential causes of secondary MN.

Histopathologic Assessment of Suspected Idiopathic Pulmonary Fibrosis: Where We Are and Where We Need to Go

CONTEXT.—

Accurate diagnosis of idiopathic pulmonary fibrosis (IPF) requires multidisciplinary diagnosis that includes clinical, radiologic, and often pathologic assessment. In 2018, the American Thoracic Society, European Respiratory Society, Japanese Respiratory Society, and the Latin American Thoracic Society (ATS/ERS/JRS/ALAT) and the Fleischner Society each published guidelines for the diagnosis of IPF, which include criteria for 4 categories of confidence of a histologic usual interstitial pneumonia (UIP) pattern.

OBJECTIVE.—

To (1) identify the role of the guidelines in pathologic assessment of UIP; (2) analyze the 4 guideline categories, including potential areas of difficulty; and (3) determine steps the Pulmonary Pathology Society and the greater pulmonary pathology community can take to improve current guideline criteria and histopathologic diagnosis of interstitial lung disease.

DATA SOURCES.—

Data were derived from the guidelines, published literature, and clinical experience.

CONCLUSIONS.—

Both guidelines provide pathologists with a tool to relay to the clinician the likelihood that a biopsy represents UIP, and serve as an adjunct, not a replacement, for traditional histologic diagnosis. There are multiple challenges with implementing the guidelines, including (1) lack of clarity on the quantity and quality of histologic findings required, (2) lack of recognition that histologic features cannot be assessed independently, and (3) lack of guidance on how pathologists should incorporate clinical and radiographic information. Current criteria for "probable UIP" and "indeterminate for UIP" hinder accurate reflection of the likelihood of IPF. These challenges highlight the need for further morphologic-based investigations in the field of pulmonary pathology.

Abstract 736: ctDNA detection in early stage non-small cell lung cancer

Introduction

Overall survival of non-small-cell lung cancer (NSCLC) patients remains poor as patients are frequently diagnosed at late stage. The evaluation of circulating tumor DNA (ctDNA) has been shown to offer a non-invasive method for cancer detection. However, detection rates of ctDNA in patients with early stage cancers have been low. The distribution of ctDNA levels in this population is unknown, and the analytical requirements for a test to detect the majority of cancers cannot be defined.

Methods

The LUCID study (LUng cancer - CIrculating tumour DNA study) recruited 100 patients with stage I-IIIB NSCLC according to the TNM 7th edition and collected plasma samples before and after radical treatment by surgery or radiotherapy +/- chemotherapy with curative intent. To measure levels of ctDNA in patients with early stage disease and very low tumor burden we developed a method for INtegration of VAriant Reads (INVAR), which uses sequencing data across hundreds to thousands of tumor-mutated loci to detect ctDNA in plasma samples at high sensitivity. We applied INVAR to 90 of the patients from the LUCID study, where tumor sequencing data was available. To measure ctDNA in the remaining LUCID patients, we applied the InVision® amplicon-based plasma sequencing assay.

Results

Across the 100 patients, ctDNA signals were observed in 67% of samples obtained prior to treatment. ctDNA was detected in 66% of cases, with ctDNA levels as low as 9.1x10-6 (9 parts per million), at a detection threshold with 95% specificity. ctDNA was detected in 52% of 60 patients with stage I NSCLC and in 88% of 40 patients with stage II/III disease. Analyzing different histological subtypes, ctDNA was detected in 79% of squamous cell carcinomas and 60% of adenocarcinomas. We found a good agreement when comparing the ctDNA results obtained from INVAR and the InVision® assay.

Conclusions

Our findings suggest that an assay with sensitivity to below 10 parts per million may be able to detect ctDNA in as many as 2/3 of patients with early stage NSCLC prior to treatment, including the majority of adenocarcinoma cases. Additionally, patient-specific analysis of ctDNA has the potential to aid in longitudinal cancer monitoring and in detection of low tumor burden and minimal residual disease. We aim to apply this approach to serial samples obtained through the LUCID study to investigate its application in treatment management.

Citation Format: Katrin Heider, Jonathan C. Wan, Davina Gale, Andrea Ruiz-Valdepenas, Florent Mouliere, James Morris, Nagmi R. Qureshi, Wendi Qian, Jerome Wulff, Nikolaos Demiris, Karen Howarth, Emma Green, Viona Rundell, Tim Eisen, Wendy Cooper, Christopher G. Smith, Charles Massie, Susan Harden, Doris M. Rassl, Robert C. Rintoul, Nitzan Rosenfeld. ctDNA detection in early stage non-small cell lung cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 736.

Targeting CD83 in mantle cell lymphoma with anti-human CD83 antibody

Objectives

Effective antibody-drug conjugates (ADCs) provide potent targeted cancer therapies. CD83 is expressed on activated immune cells including B cells and is a therapeutic target for Hodgkin lymphoma. Our objective was to determine CD83 expression on non-Hodgkin lymphoma (NHL) and its therapeutic potential to treat mantle cell lymphoma (MCL) which is currently an incurable NHL.

Methods

We analysed CD83 expression on MCL cell lines and the lymph node/bone marrow biopsies of MCL patients. We tested the killing effect of CD83 ADC in vitro and in an in vivo xenograft MCL mouse model.

Results

CD83 is expressed on MCL, and its upregulation is correlated with the nuclear factor κB (NF-κB) activation. CD83 ADC kills MCL in vitro and in vivo. Doxorubicin and cyclophosphamide (CP), which are included in the current treatment regimen for MCL, enhance the NF-κB activity and increase CD83 expression on MCL cell lines. The combination of CD83 ADC with doxorubicin and CP has synergistic killing effect of MCL.

Conclusion

This study provides evidence that a novel immunotherapeutic agent CD83 ADC, in combination with chemotherapy, has the potential to enhance the efficacy of current treatments for MCL.

IASLC Multidisciplinary Recommendations for Pathologic Assessment of Lung Cancer Resection Specimens After Neoadjuvant Therapy

Currently, there is no established guidance on how to process and evaluate resected lung cancer specimens after neoadjuvant therapy in the setting of clinical trials and clinical practice. There is also a lack of precise definitions on the degree of pathologic response, including major pathologic response or complete pathologic response. For other cancers such as osteosarcoma and colorectal, breast, and esophageal carcinomas, there have been multiple studies investigating pathologic assessment of the effects of neoadjuvant therapy, including some detailed recommendations on how to handle these specimens. A comprehensive mapping approach to gross and histologic processing of osteosarcomas after induction therapy has been used for over 40 years. The purpose of this article is to outline detailed recommendations on how to process lung cancer resection specimens and to define pathologic response, including major pathologic response or complete pathologic response after neoadjuvant therapy. A standardized approach is recommended to assess the percentages of (1) viable tumor, (2) necrosis, and (3) stroma (including inflammation and fibrosis) with a total adding up to 100%. This is recommended for all systemic therapies, including chemotherapy, chemoradiation, molecular-targeted therapy, immunotherapy, or any future novel therapies yet to be discovered, whether administered alone or in combination. Specific issues may differ for certain therapies such as immunotherapy, but the grossing process should be similar, and the histologic evaluation should contain these basic elements. Standard pathologic response assessment should allow for comparisons between different therapies and correlations with disease-free survival and overall survival in ongoing and future trials. The International Association for the Study of Lung Cancer has an effort to collect such data from existing and future clinical trials. These recommendations are intended as guidance for clinical trials, although it is hoped they can be viewed as suggestion for good clinical practice outside of clinical trials, to improve consistency of pathologic assessment of treatment response.