Pembrolizumab monotherapy for non-small cell lung cancer (NSCLC): can patient stratification be improved in the UK Tayside population? A retrospective cohort study.

OBJECTIVE: Pembrolizumab is a programmed cell death protein-1 (PD-1) inhibitor used to treat advanced patients with non-small cell lung cancer (NSCLC) with a programmed cell death ligand-1 (PD-L1) tumour proportion score (TPS) ≥50. Further sub-division of TPS-based stratification has not been evaluated in the UK, although smoking-induced tumour mutational burden and the immunogenic effects of prior radiotherapy are suggested to improve response. AIMS: To investigate if PD-L1 TPS ≥80%, smoking status or radiotherapy before or within 2 months of treatment influenced progression-free survival (PFS) in patients with NSCLC treated with pembrolizumab monotherapy. METHODS: PD-L1 TPS, smoking status and radiotherapy exposure were compared in patients with NSCLC in National Health Service (NHS) Tayside (n=100) treated with pembrolizumab monotherapy between 1 November 2017 and 18 February 2022. Survival estimates were compared using log-rank analysis, and Cox proportional hazards analysis was used to investigate the influence of potential confounding factors, including tumour stage and performance status. RESULTS: PFS was not significantly different (log-rank HR=0.330, p=0.566) comparing patients with PD-L1 TPS 50-79% and PD-L1 TPS ≥80%. Smokers had significantly improved PFS (log-rank HR=4.867, p=0.027), while patients receiving radiotherapy had significantly decreased PFS (log-rank HR=6.649, p=0.012). A Cox regression model confirmed that both radiotherapy (p=0.022) and performance status (p=0.009) were independent negative predictors of PFS. CONCLUSIONS: More rigorous PD-L1 TPS stratification did not influence survival outcomes. Smoking history improved PFS, although it was not an independent response predictor, while radiotherapy and performance status independently influenced clinical response. We suggest that further stratification of PD-L1 TPS is not warranted, while performance status and radiotherapy treatment may be additional clinically useful biomarkers of response to pembrolizumab in patients with NSCLC.

Clinical and radiographic predictors of successful therapeutic bronchoscopy for the relief of malignant central airway obstruction.

BACKGROUND: Malignant central airway obstruction (CAO) occurs in approximately 20-30% of patients with lung cancer and is associated with debilitating symptoms and poor prognosis. Multimodality therapeutic bronchoscopy can relieve malignant CAO, though carries risk. Evidence to guide clinicians regarding which patients may benefit from such interventions is sparse. We aimed to assess the clinical and radiographic predictors associated with therapeutic bronchoscopy success in relieving malignant CAO. METHODS: We reviewed all cases of therapeutic bronchoscopy performed for malignant CAO at our institution from January 2010-February 2017. Therapeutic bronchoscopy success was defined as establishing airway patency of > 50%. Patient demographics and baseline characteristics, oncology history, degree of airway obstruction, procedural interventions, and complications were compared between successful and unsuccessful groups. Univariate and multivariate logistic regression identified the significant clinical and radiographic predictors for therapeutic success. The corresponding simple and conditional odds ratio were calculated. A time-to-event analysis with Kaplan-Meier plots was performed to estimate overall survival. RESULTS: During the study period, 301 therapeutic bronchoscopies were performed; 44 (14.6%) were considered unsuccessful. Factors associated with success included never vs current smoking status (OR 5.36, 95% CI:1.45-19.74, p = 0.010), patent distal airway on CT imaging (OR 15.11, 95% CI:2.98-45.83, p < 0.0001) and patent distal airway visualized during bronchoscopy (OR 10.77, 95% CI:3.63-31.95, p < 0.001) in univariate analysis. Along with patent distal airway on CT imaging, increased time from radiographic finding to therapeutic bronchoscopy was associated with lower odds of success in multivariate analysis (OR 0.96, 95% CI:0.92-1.00, p = 0.048). Median survival was longer in the successful group (10.2 months, 95% CI:4.8-20.2) compared to the unsuccessful group (6.1 months, 95% CI:2.1-10.8, log rank p = 0.015). CONCLUSIONS: Predictors associated with successful therapeutic bronchoscopy for malignant CAO include distal patent airway visualized on CT scan and during bronchoscopy. Odds of success are higher in non-smokers, and with decreased time from radiographic finding of CAO to intervention.

Novel mouse model of indwelling pleural catheter in mice with malignant pleural effusion.

This novel mouse model mimics malignant pleural effusion drainage using an indwelling pleural catheter in humans, and provides direct access to the pleural space potentially enabling the testing of intrapleural therapies in the treatment of MPE. bit.ly/2W2kzO0.

Routine monitoring with pleural manometry during therapeutic large-volume thoracentesis to prevent pleural-pressure-related complications: a multicentre, single-blind randomised controlled trial.

BACKGROUND: In patients with non-expandable lung, removal of pleural fluid can result in excessively negative pleural pressure, which is associated with chest discomfort, pneumothorax, and re-expansion pulmonary oedema. Pleural manometry is widely used to safeguard against pressure-related complications during thoracentesis despite little evidence to support the approach. We investigated whether monitoring of pleural pressure with manometry during thoracentesis could protect against complications compared with assessment of symptoms alone. METHODS: We did a prospective randomised single-blind trial involving patients with large pleural effusions at two academic medical centres in, Nashville, TN, and Baltimore, MD, USA. Eligible patients were adults with free-flowing effusions estimated to be at least 0·5 L who could remain seated throughout the procedure. Patients were randomly assigned 1:1 to receive thoracentesis guided by symptoms only (control) or by symptoms plus manometry at timepoints based on volume drained. The randomisation schedule was computer generated, used permuted blocks of four and six, and was stratified by participating institution. Patients, who were masked to study-group assignment, were asked to rate chest discomfort on 100 mm visual analogue scales before, during, and after drainage. In both groups drainage was discontinued before complete evacuation of pleural fluid if patients developed persistent chest discomfort, intractable cough, or other complications. In the manometry group, an additional criterion for stopping was if end-expiratory pleural pressure was lower than -20 cm H2O or declined by more than 10 cm H2O between two measurements to a value less than or equal to -10 cm H2O. The primary outcome was overall chest discomfort from before the start to after the procedure measured by patients 5 min after the end of drainage. Analysis was by modified intention to treat (ie, included all patients with any procedure or outcome data). This trial is registered with ClinicalTrials.gov, number NCT02677883. FINDINGS: Between March 4, 2016, and Sept 8, 2017, 191 patients were screened, of whom 128 were randomly assigned treatment and 124 were included in the final analysis (62 in each group). Four patients were excluded because of manometer malfunction (n=2), inability to access effusion due to pleural tumour burden (n=1), and inability to remain seated (n=1). Groups did not differ for the primary outcome (mean difference in chest discomfort score 2·4 mm, 95% CI -5·7 to 10·5, p=0·56). Six (10%) of 62 patients in the control group had asymptomatic pneumothorax ex vacuo compared with none in the manometry group (p=0·01). No serious complications occurred in either group. INTERPRETATION: Measurement of pleural pressure by manometry during large-volume thoracentesis does not alter procedure-related chest discomfort. Our findings do not support the routine use of this approach. FUNDING: Centurion Medical Products.

Genetic variation in the functional ENG allele inherited from the non-affected parent associates with presence of pulmonary arteriovenous malformation in hereditary hemorrhagic telangiectasia 1 (HHT1) and may influence expression of PTPN14.

HHT shows clinical variability within and between families. Organ site and prevalence of arteriovenous malformations (AVMs) depend on the HHT causative gene and on environmental and genetic modifiers. We tested whether variation in the functional ENG allele, inherited from the unaffected parent, alters risk for pulmonary AVM in HHT1 mutation carriers who are ENG haploinsufficient. Genetic association was found between rs10987746 of the wild type ENG allele and presence of pulmonary AVM [relative risk = 1.3 (1.0018-1.7424)]. The rs10987746-C at-risk allele associated with lower expression of ENG RNA in a panel of human lymphoblastoid cell lines (P = 0.004). Moreover, in angiogenically active human lung adenocarcinoma tissue, but not in uninvolved quiescent lung, rs10987746-C was correlated with expression of PTPN14 (P = 0.004), another modifier of HHT. Quantitative TAQMAN expression analysis in a panel of normal lung tissues from 69 genetically heterogeneous inter-specific backcross mice, demonstrated strong correlation between expression levels of Eng, Acvrl1, and Ptpn14 (r2 = 0.75-0.9, P < 1 × 10(-12)), further suggesting a direct or indirect interaction between these three genes in lung in vivo. Our data indicate that genetic variation within the single functional ENG gene influences quantitative and/or qualitative differences in ENG expression that contribute to risk of pulmonary AVM in HHT1, and provide correlative support for PTPN14 involvement in endoglin/ALK1 lung biology in vivo. PTPN14 has been shown to be a negative regulator of Yap/Taz signaling, which is implicated in mechanotransduction, providing a possible molecular link between endoglin/ALK1 signaling and mechanical stress. EMILIN2, which showed suggestive genetic association with pulmonary AVM, is also reported to interact with Taz in angiogenesis. Elucidation of the molecular mechanisms regulating these interactions in endothelial cells may ultimately provide more rational choices for HHT therapy.