Pleural mesothelioma (PM) is an aggressive malignancy with poor prognosis. Although histology and pathologic stage are important prognostic factors, better prognostic biomarkers are needed. The... Show morePleural mesothelioma (PM) is an aggressive malignancy with poor prognosis. Although histology and pathologic stage are important prognostic factors, better prognostic biomarkers are needed. The ribosomal protein S6 is a downstream target of the phosphatidylinositol 3-kinase (PI3K) pathway involved in protein synthesis and cell proliferation. In previous studies, low phosphorylated S6 (pS6) immunoreactivity was significantly correlated with longer progression-free survival (PFS) and overall survival (OS) in PM patients. We aimed to correlate pS6 expression to clinical data in a large multi-centre PM cohort as part of the European Thoracic Oncology Platform (ETOP) Mesoscape project. Tissue Micro Arrays (TMAs) of PM were constructed and expression of pS6 was evaluated by a semi-quantitatively aggregate H-score. Expression results were correlated to patient characteristics as well as OS/PFS. pS6 IHC results of 364 patients from 9 centres, diagnosed between 1999 and 2017 were available. The primary histology of included tumours was epithelioid (70.3%), followed by biphasic (24.2%) and sarcomatoid (5.5%). TMAs included both treatment-naive and tumour tissue taken after induction chemotherapy. High pS6 expression (181 patients with H-score>1.41) was significantly associated with less complete resection. In the overall cohort, OS/PFS were not significantly different between pS6-low and pS6-high patients. In a subgroup analysis non-epithelioid (biphasic and sarcomatoid) patients with high pS6 expression showed a significantly shorter OS (p < 0.001, 10.7 versus 16.9 months) and PFS (p < 0.001, 6.2 versus 10.8 months). In subgroup analysis, in non-epithelioid PM patients high pS6 expression was associated with significantly shorter OS and PFS. These exploratory findings suggest a clinically relevant PI3K pathway activation in non-epithelioid PM which might lay the foundation for future targeted treatment strategies. Show less
Background: Alectinib, a highly selective next generation ALK-inhibitor, has exhibited potent anti-tumour activity in RET-rearranged NSCLC in the preclinical stage. Methods: ALERT-lung is a single... Show moreBackground: Alectinib, a highly selective next generation ALK-inhibitor, has exhibited potent anti-tumour activity in RET-rearranged NSCLC in the preclinical stage. Methods: ALERT-lung is a single-arm, phase II trial evaluating the activity of alectinib for the treatment of pretreated RET-rearranged advanced NSCLC. Alectinib was administered orally, 600 mg, twice per day until progression, refusal or unacceptable toxicity (treatment could continue beyond progression, if patient was deriving clinical benefit). Patient recruitment closed prematurely due to discouraging results for alectinib in a phase I/II study in the same indication. Results: All 14 patients who enrolled until the premature accrual closure, received at lease one dose of alectinib. Among them, median age was 61 years, majority (71 %) was female, never smokers, of ECOG PS 1. No objective response (complete or partial response) was recorded. Of the 13 evaluable patients, three (23 %) achieved and maintained disease stabilisation for 24 weeks. Up to 31 March 2021 (median follow-up 15.9 months), 12 PFS-events (92 %) were observed, with median PFS of 3.7 months (95 % C.I.: 1.8 - 7.3 months). Overall, three deaths (23 %) were reported. Seven patients (50 %) experienced grade = 3 adverse events, while three discontinued treatment due to erythema multiforme of grade 3, related to alectinib. No treatment-related serious adverse event was reported. Conclusions: Accrual into our trial was terminated early in response to other reports of limited activity of alectinib in patients with RET-fusion NSCLC and the emergence of more potent selective RET-inhibitors. Also in our trial, alectinib did not show the expected potential for anti-tumour activity in NSCLC. Show less
PD-L1, as assessed by immunohistochemistry, is a predictive biomarker for immuno-oncology treatment in lung cancer. Different scoring methods have been used to assess its status, resulting in a... Show morePD-L1, as assessed by immunohistochemistry, is a predictive biomarker for immuno-oncology treatment in lung cancer. Different scoring methods have been used to assess its status, resulting in a wide range of positivity rates. We use the European Thoracic Oncology Platform Lungscape non-small cell lung carcinoma cohort to explore this issue. PD-L1 expression was assessed via immunohistochemistry on tissue microarrays (up to four cores per case), using the DAKO 28-8 immunohistochemistry assay, following a two-round external quality assessment procedure. All samples were analyzed under the same protocol. Cross-validation of scoring between tissue microarray and whole sections was performed in 10% randomly selected samples. Cutoff points considered: >= 1, 50 (primarily), and 25%. At the two external quality assessment rounds, tissue microarray scoring agreement rates between pathologists were: 73% and 81%. There were 2008 cases with valid immunohistochemistry tissue microarray results (50% all cores evaluable). Concordant cases at 1, 25, and 50% were: 85, 91, and 93%. Tissue microarray core results were identical for 70% of cases. Sensitivity of the tissue microarray method for 1, 25, and 50% was: 80, 78, and 79% (specificity: 90, 95, 98%). Complete agreement between tissue microarrays and whole sections was achieved for 60% of the cases. Highest sensitivity rates for 1% and 50% cutoffs were detected for higher number of cores. Underestimation of PD-L1 expression on small samples is more common than overestimation. We demonstrated that classification of PD-L1 on small biopsy samples does not represent the overall expression of PD-L1 in all non-small cell cancer carcinoma cases, although the majority of cases are 'correctly' classified. In future studies, sampling more and larger biopsies, recording the biopsy size and tumor load may permit further refinement, increasing predictive accuracy. Show less
