Faculty Bibliography

Malignant pleural mesothelioma (MPM) is a highly aggressive disease, with few, if any, curative interventions. While there is growing interest in using immunotherapy and immuno-gene therapy to treat MPM, very limited data currently exist for combining these modalities with radiotherapy. Preclinical data suggest that radiotherapy may be combined with immunotherapy to produce disease regression, with abscopal effects in mice with MPM. We report the first-ever case of abscopal effect in a patient with MPM, following radiotherapy and immuno-gene therapy. The patient was a 67-year-old male with prior asbestos exposure who presented with progressive dyspnea and thoracic pain. He underwent partial right pleurectomy, pleural biopsy, and talc pleurodesis, with pathology revealing epithelioid MPM. A subsequent chest computed tomography (CT) scan and fluoro-deoxyglucose positron-emission tomography (FDG-PET) CT scan showed extensive, right-sided, fluoro-deoxyglucose (FDG) avid mass-like pleural thickening encasing the right lung, with likely mediastinal extension, nodal metastases, and vascular compression. He enrolled in a clinical trial in which he received intrapleural interferon-alpha gene therapy but needed to discontinue therapy due to supraventricular tachycardia and superior vena cava syndrome induced from tumor burden. He was emergently treated with palliative radiotherapy to 30 Gy in 10 fractions. He was then started on pemetrexed and cisplatin chemotherapy. His subsequent chest CT scan two months after radiotherapy completion showed a dramatic treatment response within, as well as outside of, the irradiated field. After completion of radiotherapy, he did experience radiation esophagitis requiring nasogastric tube placement. Herein, we highlight the feasibility and efficacy of combining immuno-gene therapy with palliative radiotherapy to produce a substantial treatment response and an abscopal effect in a patient with unresectable MPM.

Lung cancer remains the leading cause of cancer death worldwide1. With new treatment modalities, there has been a shift in focus to how we can predict who may respond to targeted treatments. Current data suggest that the human microbiome can affect lung cancer treatment through its effects on the systemic immune tone. Our group has shown that the lower airway microbiota of lung cancer patients is characterized by enrichment with oral commensals2 which triggers transcriptomic signatures (PI3K, MAPK) previously described in NSCLC 2,3. The impact of local lung dysbiosis on lung cancer progression and survival is unknown. Patients with suspicious nodules on imaging who underwent bronchoscopy were recruited. High-throughput sequencing of bacterial 16S rRNA-encoding gene amplicons was performed. Clustering was based on Dirichlet-Multinomial mixtures (DMM) modeling. RNAseq was performed on bronchial epithelial cells obtained by airway brushing. We focused our analysis on 83 NSCLC samples. Overall alpha-diversity showed that advanced stage (IIIb-VI) lower airway samples were more similar to buccal samples than local stage (I-IIIa), p<0.0001. In addition, worse 6-month and 1-year survival was associated with more similar alpha-diversity between lower airway and buccal samples (Figure 1A-D). Utilizing DMM two clusters were identified, Supraglottic-Predominant-Taxa (SPT) and Background-Predominant-Taxa (BPT). There was a significant increase in percentage of SPT in advance stage compared to local stage (p<0.008) Kaplan-Meir survival analysis shows worse survival in those with NSCLC who were clustered into the SPT group compared to BPT (p=0.0003, Figure 1E). With RNAseq, differentially expressed genes between advanced stage vs. local stage and 6-month vs. 1-year survival were not as pronounced as SPT vs. BPT (Figure 1F) suggesting that globally, transcriptomic changes between different stage and NSCLC survival were difficult to detect as compared to when airway microbiome were differentiated. In lung cancer, dysbiosis within the lower airway microenvironment, possibly by micro-aspiration, is associated with a worse 6-month and 1-year survival. This change is also associated with transcriptome changes in the local environment

BACKGROUND:In lung cancer, upregulation of the PI3K pathway is an early event that contributes to cell proliferation, survival, and tissue invasion. Upregulation of this pathway was recently described as associated with enrichment of the lower airways with bacteria identified as oral commensals. We hypothesize that host-microbe interactions in the lower airways of subjects with lung cancer affect known cancer pathways. METHODS:Airway brushes were collected prospectively from subjects with lung nodules at time of diagnostic bronchoscopy, including 39 subjects with final lung cancer diagnoses and 36 subjects with non-cancer diagnosis. Additionally, samples from 10 healthy control subjects were included. 16S rRNA gene amplicon sequencing and paired transcriptome sequencing (RNAseq) were performed on all airway samples. In addition, an in vitro model with airway epithelial cells exposed to bacteria/bacterial products was performed. RESULTS:The composition of the lower airway transcriptome in the cancer patients was significantly different from the controls, which included upregulation of ERK and PI3K signaling pathways. The lower airways of lung cancer patients were enriched for oral taxa (Streptococcus and Veillonella), which was associated with upregulation of the ERK and PI3K signaling pathways. In vitro exposure of airway epithelial cells to Veillonella, Prevotella, and Streptococcus led to upregulation of these same signaling pathways. CONCLUSIONS:The data presented here shows that several transcriptomic signatures previously identified as relevant to lung cancer pathogenesis are associated with enrichment of the lower airway microbiota with oral commensals.

BACKGROUND:This Guideline, a collaborative effort from the American Thoracic Society, Society of Thoracic Surgeons, and Society of Thoracic Radiology, aims to provide evidence-based recommendations to guide contemporary management of patients with a malignant pleural effusion (MPE). METHODS:A multidisciplinary panel developed seven questions using the PICO (Population, Intervention, Comparator, and Outcomes) format. The GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach and the Evidence to Decision framework was applied to each question. Recommendations were formulated, discussed, and approved by the entire panel. RESULTS:The panel made weak recommendations in favor of: 1) using ultrasound to guide pleural interventions; 2) not performing pleural interventions in asymptomatic patients with MPE; 3) using either an indwelling pleural catheter (IPC) or chemical pleurodesis in symptomatic patients with MPE and suspected expandable lung; 4) performing large-volume thoracentesis to assess symptomatic response and lung expansion; 5) using either talc poudrage or talc slurry for chemical pleurodesis; 6) using IPC instead of chemical pleurodesis in patients with nonexpandable lung or failed pleurodesis; and 7) treating IPC-associated infections with antibiotics and not removing the catheter. CONCLUSIONS:These recommendations, based on the best available evidence, can guide management of patients with MPE and improve patient outcomes.

The success of immune checkpoint inhibitors and the discovery of useful biomarkers to predict response to these agents has shifted much of the focus of personalized care for advanced non-small cell lung cancer towards harnessing the immune response. With further advancement, more effective immunotherapy options will emerge along with more useful biomarkers. For patients with advanced disease, minimally invasive techniques will remain most appropriate for acquisition of tissue. This is in contrast to default gold-standard large tissue specimens obtained through surgical resection. For the benefit of our patients, we will continue to learn how to do more with less. In this perspective, we review aspects of immunobiology that underlie the current state of the art of existing and emerging immunologic biomarkers that are increasingly relied upon for the care of patients with NSCLC. We then focus on PD-L1 as a clinically used biomarker with a dearth of evidence in small biopsy and cytology specimens, and evaluate studies that have sought to address this knowledge gap. In addition, we identify next steps for investigations focused on PD-L1, and also propose a paradigm shift wherein the most important sample types that need to be proven in pioneering basic science and translation work and subsequent clinical trials are the specimens most often obtained clinically.

PURPOSE OF REVIEW/OBJECTIVE:This review article describes current diagnostic and treatment modalities for malignant pleural mesothelioma (MPM). RECENT FINDINGS/RESULTS:Few randomized trials in MPM have demonstrated improved survival with current therapies. A randomized trial of first-line chemotherapy with and without bevacizumab in unresectable MPM is the only randomized trial of a new treatment regimen to demonstrate a survival benefit since cisplatin with pemetrexed became the standard of care for unresectable MPM in 2003. Unfortunately, in unresectable MPM, first-line chemotherapy alone or in combination with bevacizumab has demonstrated only limited improvements in overall survival. Recently, in nonrandomized observational studies, multimodality treatments with chemotherapy, surgery, radiation, and novel therapies have been associated with prolonged survival in select patients. Currently, there are no FDA approved second-line therapies, and clinical trial enrollment is recommended for second-line treatment. SUMMARY/CONCLUSIONS:MPM remains difficult to treat and has an overall poor prognosis despite current multimodality treatment. Thoracoscopy with multiple pleural biopsies can provide adequate tissue specimens for diagnostic testing to distinguish histologic MPM subtypes and perform molecular profiling, which influence prognosis and treatment options. In early clinical trials, immunotherapies and therapies directed against cancer-associated antigens and oncogenic alterations are emerging as promising future treatments.

Gene-mediated cytotoxic immunotherapy (GMCI) is an immune strategy implemented through local delivery of an adenovirus-based vector expressing the thymidine kinase gene (aglatimagene besadenovec, AdV-tk) followed by anti-herpetic prodrug valacyclovir. A phase I dose escalation trial of GMCI followed by chemotherapy was conducted in patients with malignant pleural effusion (MPE). AdV-tk was administered intrapleurally (IP) in three cohorts at a dose of 1 × 10¹² to 10¹³ vector particles. Primary endpoint was safety; secondary endpoints included response rate, progression-free survival, and overall survival. Nineteen patients were enrolled: median age 67 years; 14 with malignant mesothelioma, 4 non-small-cell lung cancer (NSCLC), and 1 breast cancer. There were no dose limiting toxicities. All 3 patients in cohort 2 experienced transient cytokine release syndrome (CRS). Addition of celecoxib in cohort 3 reduced the incidence and severity of CRS (none > grade 2). Three patients are alive (23-33 months after GMCI), and 3 of 4 NSCLC patients had prolonged disease stabilization; one is alive 29 months after GMCI, 3.6 years after initial diagnosis. GMCI was safe and well tolerated in combination with chemotherapy in patients with MPE and showed encouraging response. Further studies are warranted to determine efficacy.

Purpose To provide evidence-based recommendations to practicing physicians and others on the management of malignant pleural mesothelioma. Methods ASCO convened an Expert Panel of medical oncology, thoracic surgery, radiation oncology, pulmonary, pathology, imaging, and advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1990 through 2017. Outcomes of interest included survival, disease-free or recurrence-free survival, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations. Results The literature search identified 222 relevant studies to inform the evidence base for this guideline. Recommendations Evidence-based recommendations were developed for diagnosis, staging, chemotherapy, surgical cytoreduction, radiation therapy, and multimodality therapy in patients with malignant pleural mesothelioma. Additional information is available at www.asco.org/thoracic-cancer-guidelines and www.asco.org/guidelineswiki .