Background: The role of tumor-associated macrophages (TAMs) in determining the outcome between the antitumor effects of the adaptive immune system and the tumor’s anti-immunity stratagems, is controversial. Macrophages modulate their activities and phenotypes by integration of signals in the tumor microenvironment. Depending on how macrophages are activated, they may adopt so-called M1-like, antitumor or M2-like, protumor profiles. In many solid tumors, a dominance of M2-like macrophages is associated with poor outcomes but in some tumor types, strong M1-like profiles are linked to better outcomes. We aimed to investigate the interrelationship of these TAM populations to establish how they modulate the efficacy of the adaptive immune system in early lung cancer. Methods: Macrophages from matched lung (non-tumor-associated macrophages (NTAMs)) and tumor samples (TAMs) from resected lung cancers were assessed by bulk and single-cell transcriptomic analysis. Protein expression of genes characteristic of M1-like (chemokine (C-X-C motif) ligand 9) or M2-like (matrix metallopeptidase 12) functions was confirmed by confocal microscopy. Immunohistochemistry related the distribution of TAM transcriptomic signatures to density of CD8⁺ tissue-resident memory T cells (T_RM) in tumors and survival data from an independent cohort of 393 patients with lung cancer. Results: TAMs have significantly different transcriptomic profiles from NTAMs with >1000 differentially expressed genes. TAMs displayed a strong M2-like signature with no significant variation between patients. However, single-cell RNA-sequencing supported by immuno-stained cells revealed that additionally, in 25% of patients the M2-like TAMs also co-expressed a strong/hot M1-like signature (M1^hot). Importantly, there was a strong association between the density of M1^hot TAMs and T_RM cells in tumors that was in turn linked to better survival. Our data suggest a mechanism by which M1^hot TAMs may recruit T_RM cells via CXCL9 expression and sustain them by making available more of the essential fatty acids on which T_RM depend. Conclusions: We showed that in early lung cancer, expression of M1-like and M2-like gene signatures are not mutually exclusive since the same TAMs can simultaneously display both gene-expression profiles. The presence of M1^hot TAMs was associated with a strong T_RM tumor-infiltrate and better outcomes. Thus, therapeutic approaches to re-program TAMs to an M1^hot phenotype are likely to augment the adaptive antitumor responses.

Fibroblasts are poorly characterised cells that variably impact tumour progression. Here, we use single cell RNA-sequencing, multiplexed immunohistochemistry and digital cytometry (CIBERSORTx) to identify and characterise three major fibroblast subpopulations in human non-small cell lung cancer: adventitial, alveolar and myofibroblasts. Alveolar and adventitial fibroblasts (enriched in control tissue samples) localise to discrete spatial niches in histologically normal lung tissue and indicate improved overall survival rates when present in lung adenocarcinomas (LUAD). Trajectory inference identifies three phases of control tissue fibroblast activation, leading to myofibroblast enrichment in tumour samples: initial upregulation of inflammatory cytokines, followed by stress-response signalling and ultimately increased expression of fibrillar collagens. Myofibroblasts correlate with poor overall survival rates in LUAD, associated with loss of epithelial differentiation, TP53 mutations, proximal molecular subtypes and myeloid cell recruitment. In squamous carcinomas myofibroblasts were not prognostic despite being transcriptomically equivalent. These findings have important implications for developing fibroblast-targeting strategies for cancer therapy.

In idiopathic pulmonary fibrosis (IPF), the fibroblast focus is a key histological feature representing active fibroproliferation. On standard 2D pathologic examination, fibroblast foci are considered small, distinct lesions, although they have been proposed to form a highly interconnected reticulum as the leading edge of a “wave” of fibrosis. Here, we characterized fibroblast focus morphology and interrelationships in 3D using an integrated micro-CT and histological methodology. In 3D, fibroblast foci were morphologically complex structures, with large variations in shape and volume (range, 1.3 × 10 ⁴ to 9.9 × 10 ⁷ μm ³ ). Within each tissue sample numerous multiform foci were present, ranging from a minimum of 0.9 per mm ³ of lung tissue to a maximum of 11.1 per mm ³ of lung tissue. Each focus was an independent structure, and no interconnections were observed. Together, our data indicate that in 3D fibroblast foci form a constellation of heterogeneous structures with large variations in shape and volume, suggesting previously unrecognized plasticity. No evidence of interconnectivity was identified, consistent with the concept that foci represent discrete sites of lung injury and repair.

Introduction Gabapentin is an antiepileptic drug currently licensed to treat epilepsy and neuropathic pain but has been used off-label to treat acute postoperative pain. The GAP study will compare the effectiveness, cost-effectiveness and safety of gabapentin as an adjunct to standard multimodal analgesia versus placebo for the management of pain after major surgery. Methods and analysis The GAP study is a multicentre, double-blind, randomised controlled trial in patients aged 18 years and over, undergoing different types of major surgery (cardiac, thoracic or abdominal). Patients will be randomised in a 1:1 ratio to receive either gabapentin (600 mg just before surgery and 600 mg/day for 2 days after surgery) or placebo in addition to usual pain management for each type of surgery. Patients will be followed up daily until hospital discharge and then at 4 weeks and 4 months after surgery. The primary outcome is length of hospital stay following surgery. Secondary outcomes include pain, total opioid use, adverse health events, health related quality of life and costs. Ethics and dissemination This study has been approved by the Research Ethics Committee . Findings will be shared with participating hospitals and disseminated to the academic community through peer-reviewed publications and presentation at national and international meetings. Patients will be informed of the results through patient organisations and participant newsletters. Trial registration number ISRCTN63614165.

Introduction: Lung volume reduction surgery (LVRS) and endobronchial valve (EBV) placement can produce substantial benefits in appropriately selected people with emphysema. The UK Lung Volume Reduction (UKLVR) registry is a national multicentre observational study set up to support quality standards and assess outcomes from LVR procedures at specialist centres across the UK. Methods: Data were analysed for all patients undergoing an LVR procedure (LVRS/EBV) who were recruited into the study at participating centres between January 2017 and June 2022, including; disease severity and risk assessment, compliance with guidelines for selection, procedural complications and survival to February 2023. Results: Data on 541 patients from 14 participating centres were analysed. Baseline disease severity was similar in patients who had surgery n=244 (44.9%), or EBV placement n=219 (40.9%), for example, forced expiratory volume in 1 s (FEV₁₎ 32.1 (12.1)% vs 31.2 (11.6)%. 89% of cases had discussion at a multidisciplinary meeting recorded. Median (IQR) length of stay postprocedure for LVRS and EBVs was 12 (13) vs 4 (4) days(p=0.01). Increasing age, male gender and lower FEV₁%predicted were associated with mortality risk, but survival did not differ between the two procedures, with 50 (10.8%) deaths during follow-up in the LVRS group vs 45 (9.7%) following EBVs (adjusted HR 1.10 (95% CI 0.72 to 1.67) p=0.661) Conclusion: Based on data entered in the UKLVR registry, LVRS and EBV procedures for emphysema are being performed in people with similar disease severity and long-term survival is similar in both groups.