A gut microbiota rheostat forecasts responsiveness to PD-L1 and VEGF blockade in mesothelioma.

Malignant mesothelioma is a rare tumour caused by asbestos exposure that originates mainly from the pleural lining or the peritoneum. Treatment options are limited, and the prognosis is dismal. Although immune checkpoint blockade (ICB) can improve survival outcomes, the determinants of responsiveness remain elusive. Here, we report the outcomes of a multi-centre phase II clinical trial (MiST4, NCT03654833) evaluating atezolizumab and bevacizumab (AtzBev) in patients with relapsed mesothelioma. We also use tumour tissue and gut microbiome sequencing, as well as tumour spatial immunophenotyping to identify factors associated with treatment response. MIST4 met its primary endpoint with 50% 12-week disease control, and the treatment was tolerable. Aneuploidy, notably uniparental disomy (UPD), homologous recombination deficiency (HRD), epithelial-mesenchymal transition and inflammation with CD68+ monocytes were identified as tumour-intrinsic resistance factors. The log-ratio of gut-resident microbial genera positively correlated with radiological response to AtzBev and CD8+ T cell infiltration, but was inversely correlated with UPD, HRD and tumour infiltration by CD68+ monocytes. In summary, a model is proposed in which both intrinsic and extrinsic determinants in mesothelioma cooperate to modify the tumour microenvironment and confer clinical sensitivity to AtzBev. Gut microbiota represent a potentially modifiable factor with potential to improve immunotherapy outcomes for individuals with this cancer of unmet need.

Leveraging the pleural space for anticancer therapies in pleural mesothelioma.

Most patients with pleural mesothelioma (PM) present with symptomatic pleural effusion. In some patients, PM is only detectable on the pleural surfaces, providing a strong rationale for intrapleural anticancer therapy. In modern prospective studies involving expert radiological staging and specialist multidisciplinary teams, the population incidence of stage I PM (an approximate surrogate of pleura-only PM) is higher than in historical retrospective series. In this Viewpoint, we advocate for the expansion of intrapleural trials to serve these patients, given the paucity of data supporting licensed systemic therapies in this setting and the uncertainties involved in surgical therapy. We begin by reviewing the unique anatomical and physiological features of the PM-bearing pleural space, before critically appraising the evidence for systemic therapies in stage I PM and previous intrapleural PM trials. We conclude with a summary of key challenges and potential solutions, including optimal trial designs, repurposing of indwelling pleural catheters, and new technologies.

Development of Patient and Caregiver Conceptual Models Investigating the Health-Related Quality of Life Impacts of Malignant Pleural Mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a rare and usually fatal malignancy frequently linked to occupational asbestos exposures and associated with poor prognosis and considerable humanistic burden. The study aimed to develop conceptual models of the health-related quality of life (HRQoL) impact on patients with and receiving treatment for MPM, and the burden on their caregivers. METHODS: This multi-country study (Australia and United Kingdom) adopted a qualitative methodology to conduct semi-structured, independent interviews with people with MPM (n = 26), current caregivers (n = 20), and caregivers of people who had recently died because of MPM (n = 4). Participants were recruited using a purposive sampling approach and interviews conducted via telephone between January 2021 and January 2022. Transcripts were analysed using thematic analysis and used to construct conceptual models. RESULTS: Patient analysis yielded four overarching themes: (1) debilitating burden of breathlessness and fatigue; (2) physical mesothelioma symptoms experienced by patients; (3) distress of MPM on the self and family; and (4) treatment is worth 'having a go' despite the potential impact on symptoms. Caregiver analysis yielded five core themes: (1) daily life limited by caregiving duties; (2) emotional well-being and the need for support; (3) the relational role shift to caregiver; (4) time spent providing care negatively impacts work and productivity; and (5) positive aspects and outcomes of caregiving. CONCLUSIONS: This study highlights the substantial daily and emotional HRQoL impact that MPM symptoms have on patients and caregivers. Both groups reduced work, productivity, and social and leisure activities. There was evidence of positive HRQoL impacts as a result of immunotherapy and radiotherapy, but less for chemotherapy. Caregiver impacts were intensified during the end-of-life period and persisted following patient death. Evident is a need for increased psychological support, information, and advice for caregivers, increased during the end-of-life period.

A systematic review of the barriers and facilitators impacting patient enrolment in clinical trials for lung cancer.

PURPOSE: Clinical research trials are needed to enhance the medical care and treatment for lung cancer, which remains the leading cause of cancer-related deaths worldwide. While clinical trials allow for the development of novel therapies to treat cancer, the recruitment of lung cancer patients to trials is low. This review aimed to identify and synthesise the available literature concerning barriers and facilitators affecting lung cancer patients' decisions to enrol in clinical trials to guide future cancer research efforts. METHODS: Four databases were systematically searched: Academic Search Complete, CINHAL, PubMed, and PsycINFO in August 2023. A supplemental grey literature search was also conducted alongside this. Articles were quality appraised using CASP and JMI checklists, and results were narratively synthesised. RESULTS: Eighteen articles of varied design met the inclusion criteria, and results were mapped onto the Capability, Opportunity, and Motivation Behaviour (COM-B) Model to help structure and conceptualise review findings. Evidence suggests that the decision to enrol in a trial is multifaceted and informed by: when and how study information is presented, travel and trial eligibility, and altruistic hopes and fears. CONCLUSIONS: There is need to address the many different concerns that lung cancer patients have about participating in a clinical trial through the supply of accessible and timely trial information, and via the reduction of travel, expansion of study eligibility criteria, and recognition of a person's altruistic wishes, hopes, fears, and family-oriented concerns. Future research should aim to work alongside lung cancer patients, clinicians, and other stakeholders to increase research accessibility.