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Objectives The immune effects of EGFR tyrosine kinase inhibitors (EGFR-TKIs) are poorly understood. Identifying immune biomarkers could guide patient selection and optimisation of EGFR-TKI-immunotherapy combinations. Materials and methods 33 patients with NSCLC treated with an EGFR-TKI were prospectively enrolled. Peripheral blood mononuclear cells were collected pre-treatment, and after 1, 3 and 8 weeks. Flow cytometry was used to identify immune cell subsets, including PD-1 and PD-L1 expressing T cells. Immune parameters were correlated with clinical outcomes. Results Compared to healthy donors ( n = 10), patients had higher pre-treatment proportions of proliferating and PD-L1 + CD3 + T cells ( p < 0.001). Compared to patients with an EGFR mutation ( n = 12), patients without a known mutation ( n = 21) had higher proportions of proliferating CD4 + and PD-L1 + CD3 + T cells ( p = 0.03). There was a significant increase in PD-L1 + T cells after 1 week of EGFR-TKI in patients whose disease progressed compared to non-progressors. Patients with higher PD-L1 + CD3 + T cells at 1-week were more likely to progress (OR 30.3, p < 0.01) and had shorter PFS (1.6 vs. 8.8 m; p < 0.01) and OS (3.8 vs 23.2 m; p < 0.001) than those with fewer PD-L1 + CD3 + T cells. On multivariate analysis, high PD-L1 + CD3 + T cells was the only independent predictor for PFS (HR 3.7, p = 0.01), while for OS independent predictors were high PD-L1 + CD3 + T cells (HR 6.5, p < 0.01) and EGFR-negative status (HR 3.3, p = 0.04). Conclusions There was a significant correlation between PD-L1 expression on peripheral T cells and clinical outcomes in EGFR-TKI-treated NSCLC. This warrants further validation as a blood-based biomarker that may identify candidates for PD-1 inhibitors or immunotherapy-EGFR-TKI combinations. [ABSTRACT FROM AUTHOR]

Objectives Non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors have been associated with lower incidence rates of some cancers. Because asbestos can cause chronic inflammation at the pleural and peritoneal surfaces we hypothesised that NSAID and COX-2 inhibitors would inhibit the development of asbestos-induced mesothelioma. Materials and methods A murine model of asbestos-induced mesothelioma was used to test this hypothesis by providing the NSAID, aspirin, daily in the feed at 50 mg/kg or 250 mg/kg. In a parallel study, the relationship between the use of NSAID and COX-2 inhibitors and mesothelioma was investigated in a human cohort of 1738 asbestos exposed people living or working in Wittenoom, Western Australia (a crocidolite mine site). Results Aspirin did not alter the rate of disease development or increase the length of time that mice survived. Aspirin had a small but significant effect on disease latency (the time between asbestos exposure and first evidence of disease; p < 0.05) but disease progression was not affected by the continued presence of the drug. In the Wittenoom cohort, individuals who reported use of NSAIDs, COX-2 inhibitors or both did not have a lower incidence of mesothelioma (HR = 0.85; 95% CI = 0.53–1.37, p = 0.50), (HR = 0.69; 95% CI = 0.21–2.30, p = 0.55) and (HR = 0.43; 95% CI = 0.16–1.13, p = 0.087) respectively. Conclusion We conclude that NSAIDs and COX-2 inhibitors do not moderate mesothelioma development or progression in a human cohort exposed to asbestos and this result is confirmed in an autochthonous mouse model. [ABSTRACT FROM AUTHOR]

Summary: Identification of tumor marker for mesothelioma (MM) might prove useful in diagnosis as well as for monitoring tumor in response to therapy and for screening at-risk individuals. We tested the hypothesis that soluble mesothelin-related protein (SMRP), a mesothelin family member, in the serum would be such a marker. Our data show that determination of SMRP in serum is a marker of MM with a sensitivity of sensitivity 83% and specificity 95% in the first 48 MM patients tested. Changes in serum SMRP levels parallel clinical course/tumor size and SMRP is elevated in 75% of patients at diagnosis. SMRP should also be useful for monitoring disease progression, and importantly, may prove useful for screening asbestos-exposed individuals for early MM. [Copyright &y& Elsevier]