Oncogene-driven non-small cell lung cancers in patients with a history of smoking lack smoking-induced mutations.

Non-small cell lung cancers (NSCLCs) in non-smokers are mostly driven by mutations in the oncogenes EGFR, ERBB2, and MET and fusions involving ALK and RET. In addition to occurring in non-smokers, alterations in these "non-smoking-related oncogenes" (NSROs) also occur in smokers. To better understand the clonal architecture and genomic landscape of NSRO-driven tumors in smokers compared to typical-smoking NSCLCs, we investigated genomic and transcriptomic alterations in 173 tumor sectors from 48 NSCLC patients. NSRO-driven NSCLCs in smokers and non-smokers had similar genomic landscapes. Surprisingly, even in patients with prominent smoking histories, the mutational signature caused by tobacco smoking was essentially absent in NSRO-driven NSCLCs, which was confirmed in two large NSCLC datasets from other geographic regions. However, NSRO-driven NSCLCs in smokers had higher transcriptomic activities related to regulation of the cell cycle. These findings suggest that, while the genomic landscape is similar between NSRO-driven NSCLC in smokers and non-smokers, smoking still affects the tumor phenotype independently of genomic alterations.

Detection of circulating tumor DNA with ultradeep sequencing of plasma cell-free DNA for monitoring minimal residual disease and early detection of recurrence in early-stage lung cancer.

BACKGROUND: In early-stage non-small cell lung cancer (NSCLC), recurrence is frequently observed. Circulating tumor DNA (ctDNA) has emerged as a noninvasive tool to risk stratify patients for recurrence after curative intent therapy. This study aimed to risk stratify patients with early-stage NSCLC via a personalized, tumor-informed multiplex polymerase chain reaction (mPCR) next-generation sequencing assay. METHODS: This retrospective cohort study included patients with stage I-III NSCLC. Recruited patients received standard-of-care management (surgical resection with or without adjuvant chemotherapy, followed by surveillance). Whole-exome sequencing of NSCLC resected tissue and matched germline DNA was used to design patient-specific mPCR assays (Signatera, Natera, Inc) to track up to 16 single-nucleotide variants in plasma samples. RESULTS: The overall cohort with analyzed plasma samples consisted of 57 patients. Stage distribution was 68% for stage I and 16% each for stages II and III. Presurgery (i.e., at baseline), ctDNA was detected in 15 of 57 patients (26%). ctDNA detection presurgery was significantly associated with shorter recurrence-free survival (RFS; hazard ratio [HR], 3.54; 95% confidence interval [CI], 1.00-12.62; p = .009). In the postsurgery setting, ctDNA was detected in seven patients, of whom 100% experienced radiological recurrence. ctDNA positivity preceded radiological findings by a median lead time of 2.8 months (range, 0-12.9 months). Longitudinally, ctDNA detection at any time point was associated with shorter RFS (HR, 16.1; 95% CI, 1.63-158.9; p < .0001). CONCLUSIONS: ctDNA detection before surgical resection was strongly associated with a high risk of relapse in early-stage NSCLC in a large unique Asian cohort. Prospective studies are needed to assess the clinical utility of ctDNA status in this setting.

Practical challenges in lung cancer pathology: bedside care to treatment decisions.

PURPOSE OF REVIEW: Lung cancer is one of the most common malignancies in the whole world, and the pulmonologist is generally the first medical professional to meet the patient and decide what method of tumour sampling is preferable in each specific case. It is imperative for pulmonary physicians to be aware of the intricacies of the diagnostic process, and understand the multiple challenges that are encountered, from the moment the tissue specimen leaves their offices and is sent to the pathology laboratory, until the diagnosis reaches the patient and treating physician. RECENT FINDINGS: The new 2021 WHO classification of thoracic tumours recommended a minimum immunohistochemical (IHC) diagnostic panel for nonsmall cell lung cancer (NSCLC), and following publications of different institutional and country-based guidelines, advocated basic molecular testing for epithelial growth factor receptor (EGFR), anaplastic lymphoma kinase (ALK) and programmed cell death ligand 1 (PD-L1) to be initiated by the diagnosing pathologist in all cases of biopsy or resection specimens. In general, sequential testing for molecular biomarkers was not recommended due to tissue wastage, instead next generation sequencing (NGS) diagnostic panel was supported. SUMMARY: The lung cancer specimen has to undergo histologic diagnosis through a panel of IHC studies, and -preferably, a reflex molecular study by NGS including several targetable genes. Adequate communication and clinical information preclude the pathologist from "overusing" the tissue for additional studies, while focusing on preservation of material for molecular testing.

Three shades of an unusual mediastinal tumour.

Thoracic SMARCA4-deficient undifferentiated tumour (SMARCA4-UT) is an unusual and aggressive tumour. While there are approximately 100 cases of this tumour reported in the literature, there are very few detailed descriptions of its cytomorphologic characteristics, and only rare cases in which primary diagnosis was made on cytologic material. Herein we present a case with a detailed description of the appearance on three specimen types: transbronchial needle aspiration (TBNA) cytology, transbronchial needle biopsy (TBNB) and effusion cytology. Thoracic SMARCA4-UT is an important diagnosis to clinch in modern pathology because of its prognostic and therapeutic implications. We discuss an integrated approach to clinching the diagnosis with reference to clinical, radiographic, morphologic and immunohistochemical features. We also discuss possible differential diagnoses, and how they can be excluded. Cytologic and/or small biopsy diagnosis is valuable in these cases as these tumours are typically not amenable to surgical resection. With the correct diagnosis, the patient may instead be a candidate for immune checkpoint inhibitors or experimental therapy targeting SWI/SNF deficiency.

Standardized Classification of Lung Adenocarcinoma Subtypes and Improvement of Grading Assessment Through Deep Learning.

The histopathologic distinction of lung adenocarcinoma (LADC) subtypes is subject to high interobserver variability, which can compromise the optimal assessment of patient prognosis. Therefore, this study developed convolutional neural networks capable of distinguishing LADC subtypes and predicting disease-specific survival, according to the recently established LADC tumor grades. Consensus LADC histopathologic images were obtained from 17 expert pulmonary pathologists and one pathologist in training. Two deep learning models (AI-1 and AI-2) were trained to predict eight different LADC classes. Furthermore, the trained models were tested on an independent cohort of 133 patients. The models achieved high precision, recall, and F1 scores exceeding 0.90 for most of the LADC classes. Clear stratification of the three LADC grades was reached in predicting the disease-specific survival by the two models, with both Kaplan-Meier curves showing significance (P = 0.0017 and 0.0003). Moreover, both trained models showed high stability in the segmentation of each pair of predicted grades with low variation in the hazard ratio across 200 bootstrapped samples. These findings indicate that the trained convolutional neural networks improve the diagnostic accuracy of the pathologist and refine LADC grade assessment. Thus, the trained models are promising tools that may assist in the routine evaluation of LADC subtypes and grades in clinical practice.

Imaging and treatment with 68Gallium and 177Lutetium-DOTATATE in a rare SSTR2 and ESWR1-CREM fusion positive undifferentiated round cell tumour of the lung.

The authors present a 45-year-old lady with a rare undifferentiated round cell tumour of the lung with a ESWR1-CREM fusion gene that progressed despite multiple lines of therapy. The tumour was Somatostatin Receptors Type 2 (SSTR2) positive and avid on 68Gallium-DOTATATE imaging. This allowed for novel treatment with Peptide Receptor Radionuclide Therapy (PRRT) using 177Lutetium-DOTATATE after all other standard of care options were exhausted.

PD-L1 score as a prognostic biomarker in asian early-stage epidermal growth factor receptor-mutated lung cancer.

AIM: To determine the prognostic value of programmed death-ligand 1 (PD-L1) score in early-stage epidermal growth factor receptor (EGFR)-mutated non-small cell lung cancer (NSCLC), contrasted against EGFR-wildtype NSCLC. METHODS: Consecutive patients with Stage IA-IIIA NSCLC diagnosed 1st January 2010-31st December 2019 at National Cancer Centre Singapore with evaluable EGFR and PD-L1 status were included. Co-primary end-points were 2-year disease-free survival (DFS) and 5-year overall survival (OS) by Kaplan-Meier method. RESULTS: 455 patients were included (267 EGFR-mutated, EGFR-M+; 188 EGFR-wildtype, wt). Median age at diagnosis was 65 years, 52.3% (238/455) of patients were males, 62.9% (286/455) of patients were never-smokers and 92.5% (421/455) of patients had R0 resection. Stage IA comprised 42.4% (193/455) of patients, Stage IB comprised 23.1% (105/455) of patients, Stage IIA comprised 10.8% of patients (49/455), Stage IIB comprised 5.1% of patients (23/455) and Stage IIIA comprised 18.7% (85/455) of patients. Among EGFR-M+, 45.3% (121/267) were Ex19del and 41.9% (112/267) were L858R. PD-L1 ≥1% among EGFR-M+ and EGFR-wt was 45.3% (121/267) and 54.8% (103/188) respectively (p = 0.047). At median follow-up of 47 months, 178 patients had relapsed. Among EGFR-M+, 2-year DFS comparing PD-L1 <1% and PD-L1 ≥1% was 78.1% and 67.6% (p = 0.007) while 5-year OS was 59.5% and 42.8% (p = 0.001), respectively. Controlling for age, gender, lymphovascular invasion, adjuvant therapy and resection margin status, PD-L1 ≥1% (hazard ratio, HR 2.18, 95% CI 1.04-4.54, p = 0.038), stage IIB (HR 7.78, 95% CI 1.72-35.27, p = 0.008) and stage IIIA (HR 4.45, 95% CI 1.44-13.80, p = 0.01) emerged as independent predictors of inferior OS on multivariable analysis. In exploratory analysis, genomic analysis of 81 EGFR-M+ tumours was performed. PD-L1 ≥1% tumours had significantly higher rates of TP53 mutations (36.1% versus 15.6%, p = 0.04), with predominantly missense mutations. CONCLUSION: PD-L1 ≥1% is an independent predictor of worse OS among early-stage EGFR-mutated NSCLC and is associated with inferior DFS regardless of EGFR status. PD-L1 score as a risk stratification factor should be evaluated in prospective adjuvant studies among EGFR-mutated NSCLC.

Overcoming the Interobserver Variability in Lung Adenocarcinoma Subtyping: A Clustering Approach to Establish a Ground Truth for Downstream Applications.

CONTEXT.­: The accurate identification of different lung adenocarcinoma histologic subtypes is important for determining prognosis but can be challenging because of overlaps in the diagnostic features, leading to considerable interobserver variability. OBJECTIVE.­: To provide an overview of the diagnostic agreement for lung adenocarcinoma subtypes among pathologists and to create a ground truth using the clustering approach for downstream computational applications. DESIGN.­: Three sets of lung adenocarcinoma histologic images with different evaluation levels (small patches, areas with relatively uniform histology, and whole slide images) were reviewed by 17 international expert lung pathologists and 1 pathologist in training. Each image was classified into one or several lung adenocarcinoma subtypes. RESULTS.­: Among the 4702 patches of the first set, 1742 (37%) had an overall consensus among all pathologists. The overall Fleiss κ score for the agreement of all subtypes was 0.58. Using cluster analysis, pathologists were hierarchically grouped into 2 clusters, with κ scores of 0.588 and 0.563 in clusters 1 and 2, respectively. Similar results were obtained for the second and third sets, with fair-to-moderate agreements. Patches from the first 2 sets that obtained the consensus of the 18 pathologists were retrieved to form consensus patches and were regarded as the ground truth of lung adenocarcinoma subtypes. CONCLUSIONS.­: Our observations highlight discrepancies among experts when assessing lung adenocarcinoma subtypes. However, a subsequent number of consensus patches could be retrieved from each cluster, which can be used as ground truth for the downstream computational pathology applications, with minimal influence from interobserver variability.

A single tertiary institution review of the international system for serous fluid cytopathology and the impact of cell block and ancillary studies on its performance.

INTRODUCTION: We sought to assess the utility of the International System for Serous Fluid Cytopathology (TIS) in the context of our department's routine practice. MATERIALS AND METHODS: We examined 1028 archived effusion cytology (pleural, peritoneal, and pericardial) cases from 2018 to 2019, and re-classified them along the international system into the following diagnostic categories: nondiagnostic (ND), negative for malignancy (NFM), atypia cells of undetermined significance (AUS), suspicious for malignancy (SFM), and malignant (MAL). RESULTS: The full distribution of the cases examined was as follows: ND 2.0%; NFM 66.1%; AUS 6.0%; SFM 4.7%; MAL 21.2%. Overall risk of malignancy for each category was calculated as: ND 30.0%; NFM 18.0%; AUS 61.9%; SFM 100%; MAL 94.4%. The overall performance attributes of TIS were as follows: sensitivity 57.1%; specificity 98.3%; positive predictive value 94.4%; negative predictive value 82.0%; diagnostic accuracy 84.5%. CONCLUSIONS: The new classification was simple and intuitive to use and our results appear to fall within the expected ranges of the new guidelines, with risk of malignancy and accuracy comparable to similar studies. The availability of a cell block allowed for refinement of the diagnosis in a majority of cases with equivocal cytology, though this was dependent on the cell yield.

A Randomized Phase 2 Trial of Nivolumab Versus Nivolumab-Ipilimumab Combination in EGFR-Mutant NSCLC.

Introduction: Although immune checkpoint inhibitors (ICIs) have dramatically improved outcomes for nononcogene-addicted NSCLC, monotherapy with programmed cell death protein-1 (PD1) inhibition has been associated with low efficacy in the EGFR-mutant setting. Given the potential for synergism with combination checkpoint blockade, we designed a trial to test the activity of combination nivolumab (N)-ipilimumab (NI) in EGFR-mutant NSCLC. Methods: This is a randomized phase 2 study (NCT03091491) of N versus NI combination in EGFR tyrosine kinase inhibitor (TKI)-resistant NSCLC, with crossover permitted on disease progression. The primary end point was the objective response rate, and the secondary end points included progression-free survival, overall survival, and safety of ICI after EGFR TKI. Results: Recruitment ceased owing to futility after 31 of 184 planned patients were treated. A total of 15 patients received N and 16 received NI combination. There were 16 patients (51.6%) who had programmed death-ligand (PDL1) 1 greater than or equal to 1%, and 15 (45.2%) harbored EGFR T790M. Five patients derived clinical benefits from ICI with one objective response (objective response rate 3.2%), and median progression-free survival was 1.22 months (95% confidence interval: 1.15-1.35) for the overall cohort. None of the four patients who crossed over achieved salvage response by NI. PDL1 and tumor mutational burden (TMB) were not able to predict ICI response. Rates of all grade immune-related adverse events were similar (80% versus 75%), with only two grade 3 events. Conclusions: Immune checkpoint inhibition is ineffective in EGFR TKI-resistant NSCLC. Whereas a small subgroup of EGFR-mutant NSCLC may be immunogenic and responsive to ICI, better biomarkers are needed to select appropriate patients.

Pathological Findings in COVID-19 and Non-COVID-19 Vaccine-Associated Lymphadenopathy: A Systematic Review.

COVID-19 vaccine-associated lymphadenopathy (C19-VAL) is increasingly encountered with the widespread use of the vaccine in controlling the outbreak. We aim to characterize the pathological findings of COVID-19 and non-COVID-19 vaccine-associated lymphadenopathy (NC19-VAL). A search for studies that reported pathological findings in vaccine-associated lymphadenopathy on PubMed and Google Scholar was performed on 11 December 2021. C19-VAL studies were pooled for analysis. These studies were split into clinical lymphadenopathy (CL) and subclinical lymphadenopathy detected on imaging (SLDI) for subgroup analysis. A total of 25 studies were related to COVID-19 vaccines, and 21 studies were included in the pooled analysis. The pooled analysis included 37 patients with a mean age of 47.8 ± 19.1 years old, and 62.2% were females. The mean duration from last vaccination to development of CL/SLDI was 14.5 ± 11.0 days. Most were diagnosed as reactive or negative for malignancy (28/37, 75.5%), followed by Kikuchi-Fujimoto disease (KFD) (3/37, 8.1%), florid lymphoid hyperplasia (2/37, 5.4%), and granulomatous inflammation (2/37, 5.4%). Metastases were reported in two patients with a history of malignancy (2/37, 5.4%). Cases with florid lymphoid hyperplasia and KFD were younger than those with reactive changes. A total of 14 studies were related to non-COVID-19 vaccines. Caseating granulomatous inflammation was reported in BCG vaccine-associated lymphadenopathy, while other vaccines were associated with reactive lymphoid hyperplasia, florid post-vaccinal reactions, and KFD. Although most C19-VAL cases were reported as reactive or negative for malignancy, other diagnoses included florid lymphoid hyperplasia, KFD, and granulomatous inflammation. Metastases were reported in lymphadenopathy of patients with a history of malignancy, who had been incidentally vaccinated. In conclusion, C19-VAL can yield different histopathological diagnoses when sampled, most of which require clinical and radiological correlation for optimal patient management.

Clinical and Genomic Features of HER2 Exon 20 Insertion Mutations and Characterization of HER2 Expression by Immunohistochemistry in East Asian Non-Small-Cell Lung Cancer.

PURPOSE: HER2-altered non-small-cell lung cancer (NSCLC) represents a diverse subgroup, including mutations, amplifications, and overexpression. However, HER2 exon 20 insertion mutations are emerging as a distinct molecular subtype with expanding therapeutic options. We describe the molecular epidemiology and genomic features of HER2-altered NSCLC in an Asian tertiary cancer center. METHODS: We identified patients with HER2-mutated NSCLC in our institutional database, collating clinicopathological features and treatment outcomes. The genomic landscape of human epidermal growth factor receptor 2 (HER2)-mutated NSCLC was further evaluated using whole-exome sequencing (WES) data from combined local and publicly available data sets. HER2 amplification and overexpression as selection biomarkers in NSCLC were further interrogated using HER2 immunohistochemistry and correlations with WES and RNA sequencing data. RESULTS: Among 1,252 patients with consecutive lung adenocarcinoma undergoing routine next-generation sequencing, the prevalence of HER2 mutations was 3.1%-exon 20 insertion mutations comprised 2.7%. We examined the clinicopathological features in 55 patients with HER2-mutated NSCLC comprising 40 exon 20 insertion and 15 nonexon 20 insertion mutations. The most common exon 20 insertion mutation was HER2Y772_A775dup in 30 (75%), followed by HER2G776delinsVC in five patients (13%). There were limited responses to HER2-directed therapies apart from trastuzumab-deruxtecan, and no responses were seen with immunotherapy monotherapy. Evaluating the genomics features of HER2 exon 20 insertion mutations using WES data revealed low tumor mutational burden (TMB), low incidence of cancer driver comutations, and a predominance of aging mutational signature-similar to EGFR-mutated tumors. In contrast, uncommon (or nonexon 20 insertion) HER2-mutated tumors resembled EGFR wild-type tumors with higher TMB, higher frequency of cancer driver comutations, and greater presence of smoking and APOBEC mutational signature. Finally, in evaluating HER2 immunohistochemistry in all lung adenocarcinoma, there was significant discordance comparing different scoring systems and poor correlation with HER2 RNA expression and HER2 amplification. CONCLUSION: The incidence of HER2 mutations is 3.1% in East Asian nonsquamous NSCLC. HER2 exon 20 insertion-mutated tumors appear genomically distinct from uncommon (nonexon 20 insertion) HER2 mutations, the latter demonstrating higher TMB, co-occurring drivers, and predominant nonaging mutational signature. The therapeutic implications of the genomic and clinical features of HER2-mutated NSCLC warrant further investigation.

Obtaining spatially resolved tumor purity maps using deep multiple instance learning in a pan-cancer study.

Tumor purity is the percentage of cancer cells within a tissue section. Pathologists estimate tumor purity to select samples for genomic analysis by manually reading hematoxylin-eosin (H&E)-stained slides, which is tedious, time consuming, and prone to inter-observer variability. Besides, pathologists' estimates do not correlate well with genomic tumor purity values, which are inferred from genomic data and accepted as accurate for downstream analysis. We developed a deep multiple instance learning model predicting tumor purity from H&E-stained digital histopathology slides. Our model successfully predicted tumor purity in eight The Cancer Genome Atlas (TCGA) cohorts and a local Singapore cohort. The predictions were highly consistent with genomic tumor purity values. Thus, our model can be utilized to select samples for genomic analysis, which will help reduce pathologists' workload and decrease inter-observer variability. Furthermore, our model provided tumor purity maps showing the spatial variation within sections. They can help better understand the tumor microenvironment.

Mass-forming immunoglobulin G4-related disease shows indolent clinical course after surgical resection, clinicopathological analysis of a series of 15 cases.

The purpose of this study is to characterize the clinicopathological features of mass-forming immunoglobulin G4-related disease (IgG4-RD). A retrospective search for cases of mass-forming IgG4-RD diagnosed at Singapore General Hospital between 2008 and 2019 was performed. A total of 15 cases of mass-forming IgG4-RD were identified. The male-to-female ratio was 2.5:1, and the median age was 61 years old. The majority of cases showed a solitary lesion (12/15) with a mean size of 35 mm. IgG4-RD was considered as a clinical differential diagnosis only in one case (1/15) prior to the surgical resection. Diagnostic histopathological features, such as dense lymphoplasmacytic infiltrate positive for IgG4 plasma cells (15/15), storiform fibrosis (15/15), and obliterative phlebitis (9/15), were observed in most cases. These findings were distributed heterogeneously within the lesions. Cases with single organ involvement showed a low relapse rate (2/10) and normal serum IgG4 level after surgical resection. Mass-forming IgG4-RD has a male predilection and involves various organ systems. It may be initially misdiagnosed as malignancy and undergo surgical resection. The diagnostic histological features of IgG4-RD are readily identified in different organs. However, they may be distributed heterogeneously within a single lesion. Cases of single organ involvement show an indolent clinical course and normal serum IgG4 level after surgical resection.

Association of Clinicopathologic and Molecular Tumor Features With Recurrence in Resected Early-Stage Epidermal Growth Factor Receptor-Positive Non-Small Cell Lung Cancer.

Importance: The recently published ADAURA study has posed a significant dilemma for clinicians in selecting patients for adjuvant osimertinib. Risk factors for recurrence in early-stage epidermal growth factor receptor (EGFR)-positive non-small cell lung cancer (NSCLC) also remain undefined. Objective: To determine clinicopathologic characteristics and recurrence patterns of resected early-stage EGFR-positive NSCLC, using wildtype EGFR as a comparator cohort, and identify features associated with recurrence. Design, Setting, and Participants: This is a cohort study including patients diagnosed with AJCC7 Stage IA to IIIA NSCLC between January 1, 2010, and June 30, 2018, who underwent curative surgical procedures at a specialist cancer center in Singapore. The cutoff for data analysis was October 15, 2020. Patient demographic characteristics, treatment history, and survival data were collated. In exploratory analysis, whole-exome sequencing was performed in a subset of 86 patients. Data were analyzed from September 3, 2020, to June 6, 2021. Exposures: Adjuvant treatment was administered per investigator's discretion. Main Outcomes and Measures: The main outcome was 2-year disease-free survival (DFS). Results: A total of 723 patients were included (389 patients with EGFR-positive NSCLC; 334 patients with wildtype EGFR NSCLC). There were 366 women (50.6%) and 357 men (49.4%), and the median (range) age was 64 (22-88) years. A total of 299 patients (41.4%) had stage IA NSCLC, 155 patients (21.4%) had stage IB NSCLC, 141 patients (19.5%) had stage II NSCLC, and 125 patients (17.3%) had stage IIIA NSCLC. Compared with patients with wildtype EGFR NSCLC, patients with EGFR-positive NSCLC were more likely to be women (106 women [31.7%] vs 251 women [64.5%]) and never smokers (121 never smokers [36.2%] vs 317 never smokers [81.5%]). At median (range) follow up of 46 (0-123) months, 299 patients (41.4%) had cancer recurrence. There was no statistically significant difference in 2-year DFS for EGFR-positive and wildtype EGFR NSCLC (70.2% [95% CI, 65.3%-74.5%] vs 67.6% [95% CI, 62.2%-72.4%]; P = .70), although patients with EGFR-positive NSCLC had significantly better 5-year overall survival (77.7% [95% CI, 72.4%-82.1%] vs 66.6% [95% CI, 60.5%-72.0%]; P = .004). Among patients with EGFR-positive NSCLC, 2-year DFS was 81.0% (95% CI, 74.0%-86.3%) for stage IA, 78.4% (95% CI, 68.2%-85.6%) for stage IB, 57.1% (95% CI, 43.7%-68.4%) for stage II, and 46.6% (95% CI, 34.7%-57.7%) for stage IIIA. Overall, 5-year DFS among patients with stage IB through IIIA was 37.2% (95% CI, 30.1%-44.3%). Sites of disease at recurrence were similar between EGFR-positive and wildtype EGFR NSCLC, with locoregional (64 patients [16.5%] vs 56 patients [16.8%]), lung (41 patients [10.5%] vs 40 patients [12.0%]), and intracranial (37 patients [9.5%] vs 22 patients [6.6%]) metastases being the most common. A risk estimation model incorporating genomic data and an individual patient nomogram using clinicopathologic features for stage I EGFR-positive NSCLC was developed to improve risk stratification. Conclusions and Relevance: This cohort study found that recurrence rates were high in early-stage EGFR-positive NSCLC including stage IA, yet 37.2% of patients with stage IB through IIIA were cured without adjuvant osimertinib. Further studies are needed to elucidate individualized surveillance and adjuvant treatment strategies for early-stage EGFR-positive NSCLC.

Revisiting neoadjuvant therapy in non-small-cell lung cancer.

Despite the rapidly evolving treatment landscape in advanced non-small-cell lung cancer (NSCLC), developments in neoadjuvant and adjuvant treatments have been nascent by comparison. Establishing overall survival benefit in the early-stage setting has been challenging because of the need for large trials and long-term survival data. Encouraged by improved treatment outcomes with a biomarker-driven approach in advanced NSCLC, and recognising the need to improve survival outcomes in early-stage NSCLC, there has been renewed interest in revisiting neoadjuvant strategies. Multiple neoadjuvant trials with targeted therapy and immunotherapy, either alone or in combination with chemotherapy, have yielded unique insights into traditional response parameters, such as the discordance between RECIST response and pathological response, and expanded opportunities for biomarker discovery. With further standardisation of trial endpoints across studies, coupled with the implementation of novel technologies including radiomics and digital pathology, individual risk-stratified neoadjuvant treatment approaches are poised to make a striking impact on the outcomes of early-stage NSCLC.

Autoimmune pulmonary alveolar proteinosis with a history of vaping and vitamin E-positive bronchoalveolar lavage.

Pulmonary alveolar proteinosis (PAP) can be due to primary autoimmune and secondary causes, including e-cigarette, or vaping, product use-associated lung injury. We present a 33-year-old male presenting with PAP and a history of vaping. Serum anti-granulocyte-macrophage colony-stimulating factor antibodies were present. Vitamin E (VE), but not VE acetate, was detected in bronchoalveolar lavage. This is the first report of potential association between vaping and autoimmune PAP.

Integrative Profiling of T790M-Negative EGFR-Mutated NSCLC Reveals Pervasive Lineage Transition and Therapeutic Opportunities.

PURPOSE: Despite the established role of EGFR tyrosine kinase inhibitors (TKIs) in EGFR-mutated NSCLC, drug resistance inevitably ensues, with a paucity of treatment options especially in EGFR T790M-negative resistance. EXPERIMENTAL DESIGN: We performed whole-exome and transcriptome analysis of 59 patients with first- and second-generation EGFR TKI-resistant metastatic EGFR-mutated NSCLC to characterize and compare molecular alterations mediating resistance in T790M-positive (T790M+) and -negative (T790M-) disease. RESULTS: Transcriptomic analysis revealed ubiquitous loss of adenocarcinoma lineage gene expression in T790M- tumors, orthogonally validated using multiplex IHC. There was enrichment of genomic features such as TP53 alterations, 3q chromosomal amplifications, whole-genome doubling and nonaging mutational signatures in T790M- tumors. Almost half of resistant tumors were further classified as immunehot, with clinical outcomes conditional on immune cell-infiltration state and T790M status. Finally, using a Bayesian statistical approach, we explored how T790M- and T790M+ disease might be predicted using comprehensive genomic and transcriptomic profiles of treatment-naïve patients. CONCLUSIONS: Our results illustrate the interplay between genetic alterations, cell lineage plasticity, and immune microenvironment in shaping divergent TKI resistance and outcome trajectories in EGFR-mutated NSCLC. Genomic and transcriptomic profiling may facilitate the design of bespoke therapeutic approaches tailored to a tumor's adaptive potential.

Individualized Molecular Profiling for Allocation to Clinical Trials Singapore Study-An Asian Tertiary Cancer Center Experience.

PURPOSE: Precision oncology has transformed the management of advanced cancers through implementation of advanced molecular profiling technologies to identify increasingly defined subsets of patients and match them to appropriate therapy. We report outcomes of a prospective molecular profiling study in a high-volume Asian tertiary cancer center. PATIENTS AND METHODS: Patients with advanced cancer were enrolled onto a prospective protocol for genomic profiling, the Individualized Molecular Profiling for Allocation to Clinical Trials Singapore study, at the National Cancer Center Singapore. Primary objective was to identify molecular biomarkers in patient's tumors for allocation to clinical trials. The study commenced in February 2012 and is ongoing, with the results of all patients who underwent multiplex next-generation sequencing (NGS) testing until December 2018 presented here. The results were discussed at a molecular tumor board where recommendations for allocation to biomarker-directed trials or targeted therapies were made. RESULTS: One thousand fifteen patients were enrolled with a median age of 58 years (range 20-83 years). Most common tumor types were lung adenocarcinoma (26%), colorectal cancer (15%), and breast cancer (12%). A total of 1,064 NGS assays were performed, on fresh tumor tissue for 369 (35%) and archival tumor tissue for 687 (65%) assays. TP53 (39%) alterations were most common, followed by EGFR (21%), KRAS (14%), and PIK3CA (10%). Of 405 NGS assays with potentially actionable alterations, 111 (27%) were allocated to a clinical trial after molecular tumor board and 20 (4.9%) were enrolled on a molecularly matched clinical trial. Gene fusions were detected in 23 of 311 (7%) patients tested, including rare fusions in new tumor types and known fusions in rare tumors. CONCLUSION: Individualized Molecular Profiling for Allocation to Clinical Trials Singapore demonstrates the feasibility of a prospective broad molecular profiling program in an Asian tertiary cancer center, with the ability to develop and adapt to a dynamic landscape of precision oncology.

Intratumoral CD39+CD8+ T Cells Predict Response to Programmed Cell Death Protein-1 or Programmed Death Ligand-1 Blockade in Patients With NSCLC.

INTRODUCTION: Programmed cell death protein-1 (PD-1) and programmed death-ligand 1 (PD-L1) blockade is currently widely used in the treatment of metastatic NSCLC. Despite available biomarker stratification, clinical responses vary. Thus, the search for novel biomarkers with improved response prediction is ongoing. Previously, using mass cytometry or cytometry by time-of-flight (CyTOF), our group demonstrated that CD39+CD8+ immune cells represent tumor antigen-specific, cytotoxic T cells in treatment-naive NSCLC. We hypothesized that accurate quantitation of this T cell subset would predict immunotherapy outcome. METHODS: To translate this to a clinical setting, the present study compared CyTOF data with a range of clinically relevant methods, including conventional immunohistochemistry (IHC), multiplex IHC or immunofluorescence (mIHC), and gene expression assay by NanoString. RESULTS: Quantification using mIHC but not conventional IHC or NanoString correlated with the CyTOF results. The specificity and sensitivity of mIHC were then evaluated in a separate retrospective NSCLC cohort. CD39+CD8+ T cell proportion, as determined by mIHC, successfully stratified responders and nonresponders to PD-1 or PD-L1 inhibitors (objective response rate of 63.6%, compared with 0% for the negative group). This predictive capability was independent from other confounding factors, such as total CD8+ T cell proportion, CD39+ lymphocyte proportion, PD-L1 positivity, EGFR mutation status, and other clinicopathologic parameters. CONCLUSIONS: Our results suggest that the mIHC platform is a clinically relevant method to evaluate CD39+CD8+ T cell proportion and that this marker can serve as a potential biomarker that predicts response to PD-1 or PD-L1 blockade in patients with NSCLC. Further validation in additional NSCLC cohorts is warranted.