Malignant pleural mesothelioma (MPM) is a highly lethal cancer of the lining of the chest cavity. To expand our understanding of MPM, we conducted a comprehensive integrated genomic study, including the most detailed analysis of BAP1 alterations to date. We identified histology-independent molecular prognostic subsets, and defined a novel genomic subtype with TP53 and SETDB1 mutations and extensive loss of heterozygosity. We also report strong expression of the immune checkpoint gene VISTA in epithelioid MPM, strikingly higher than in other solid cancers, with implications for the immune response to MPM and for its immunotherapy. Our findings highlight new avenues for further investigation of MPM biology and novel therapeutic options.

BACKGROUND:The secondary epidermal growth factor receptor (EGFR) mutation Thr790Met (T790M) accounts for approximately half of acquired resistances to EGFR-tyrosine kinase inhibitor (TKI). Recent reports have demonstrated that the emergence of T790M predicts a favorable prognosis and indolent progression. However, rebiopsy to confirm T790M status can be challenging due to limited tissue availability and procedural feasibility, and little is known regarding the differences among patients with or without T790M mutation. METHODS: The study investigated 78 EGFR-mutant patients who had undergone rebiopsy after TKI failure. The peptide nucleic acid-locked nucleic acid polymerase chain reaction clamp method was used in EGFR mutational analyses. Various patient characteristics and postprogression survivals (PPSs) after initial TKI failure were retrospectively compared in patients with and without T790M. RESULTS: The T790M mutation was identified in 4 (17%) of 24 central nervous system lesions, and in 22 (41%) of 54 other lesions (P 5.0417). No other characteristics had a statistical association with T790M prevalence. Median PPS was 31.4 months in 26 patients with T790M, and 11.4 months in 52 patients without T790M (P 5.0017). In the multivariate analysis, statistically significant factors for longer PPS included T790M-positive, good performance status, and no carcinomatous meningitis. CONCLUSIONS: The emergence of T790M in central nervous system lesions was rare, compared with other lesions. Patients with T790M after TKI failure appear to have better prognoses than those without T790M. TKI rechallenge or continuous administration beyond progression may be effective after initial TKI failure. Cancer 2013;119:4325-32.

CT-guided lung biopsy has a high diagnostic accuracy. Complication rates were acceptable and comparable to those of previous studies.

7528 Background: The secondary epidermal growth factor receptor (EGFR) mutation T790M accounts for approximately half of acquired resistances to EGFR-tyrosine kinase inhibitors (TKI). A recent report has demonstrated the presence of T790M predicts a favorable prognosis and indolent progression, compared to the absence of T790M after TKI failure. However, rebiopsy to confirm T790M status can be challenging due to limited tissue availability and procedural feasibility, and little is known regarding the differences among patients with or without T790M. Methods: We investigated 73 patients harboring EGFR sensitive mutations who had undergone rebiopsy to confirm the emergence of T790M after TKI failure. The peptide nucleic acid-locked nucleic acid PCR clamp method was used in EGFR mutational analyses. Patient characteristics (age, gender, smoking history, performance status, EGFR mutation site, initial TKI, response to initial TKI, line of initial TKI, progression-free survival with initial TKI, and biopsy site) and postprogression survivals (PPS) after initial TKI failure, were retrospectively compared in patients with and without T790M. Results: We identified T790M in 2 (10%) of 21 central nervous system (CNS) (19 cerebrospinal fluid and 2 brain tissue) specimens, and in 20 (38%) of 52 other lesions (25 lung tissue, 24 pleural effusion, and 3 lymph node) (p = 0.0225). Other characteristics had no statistical association with the detection of T790M. Median PPS in patients with T790M was 34.0 months, and in those without T790M, 14.5 months (p = 0.0038). Although none of our patients received TKIs continuously after initial failure, 56 (77%) patients were re-administered TKIs. Regardless of T790M status, PPS in patients with TKI re-administration (23.4 months) was significantly longer than without re-administration (10.4 months) (p = 0.0085). Conclusions: The emergence of T790M in CNS is rare compared with other lesions. Patients with T790M after TKI failure have significantly better prognosis than those without T790M. The effectiveness of TKI re-administration or continuous administration beyond progression is suggested after initial TKI failure.

High-dose erlotinib suggested its efficacy and safety in some patients with refractory LM. It represents a potential therapeutic option against LM after failure of standard-dose EGFR-TKIs, especially to palliate LM-related neurological symptoms.

BackgroundThe aim of this study was to detect the epidermal growth factor receptor (EGFR)-activating mutations and other oncogene alterations in patients with non-small-cell lung cancers (NSCLC) who experienced a treatment failure in response to EGFR-tyrosine kinase inhibitors (TKIs) with a next generation sequencer.MethodsFifteen patients with advanced NSCLC previously treated with EGFR-TKIs were examined between August 2005 and October 2014. For each case, new biopsies were performed, followed by DNA sequencing on an Ion Torrent Personal Genome Machine (PGM) system using the Ion AmpliSeq Cancer Hotspot Panel version 2.ResultsAll 15 patients were diagnosed with NSCLC harboring EGFR-activating mutations (seven cases of exon 19 deletion, seven cases of L858R in exon 21, and one case of L861Q in exon 21). Of the 15 cases, acquired T790M resistance mutations were detected in 9 (60.0 %) patients. In addition, other mutations were identified outside of EGFR, including 13 cases (86.7 %) exhibiting TP53 P72R mutations, 5 cases (33.3 %) of KDR Q472H, and 2 cases (13.3 %) of KIT M541L.ConclusionsHere, we showed that next-generation sequencing (NGS) is able to detect EGFR T790M mutations in cases not readily diagnosed by other conventional methods. Significant differences in the degree of EGFR T790M and other EGFR-activating mutations may be indicative of the heterogeneity of disease phenotype evident within these patients. The co-existence of known oncogenic mutations within each of these patients may play a role in acquired EGFR-TKIs resistance, suggesting the need for alternative treatment strategies, with PCR-based NGS playing an important role in disease diagnosis.

Patients with a high CYFRA 21-1 level have significantly shorter PFS. CYFRA 21-1 is not a prognostic but a predictive marker of EGFR-TKI treatment in EGFR-mutated NSCLC patients.

Malignant pleural effusion (MPE) is a common complication of lung cancer with devastating consequences. Since vascular endothelial growth factor (VEGF) has been implicated in MPE, we hypothesized that bevacizumab, an anti-VEGF antibody, may be effective against MPE in patients with non-small-cell lung cancer (NSCLC). We analysed the records of 21 patients treated for NSCLC-associated MPE between February, 2010 and August, 2013 who consequently underwent bevacizumab combination chemotherapy at the Institute of Biomedical Research and Innovation Hospital. The results were retrospectively analysed using case records and radiographic imaging records. Three patients exhibited complete response of the pleural effusion to bevacizumab treatment, 8 patients achieved a partial response (PR) and 6 patients showed no response. When efficacy was assessed by the response of the measurable primary or metastatic lesions to the treatment, 5 patients achieved a PR, 13 patients had stable disease and 3 patients exhibited progressive disease. The response rate (RR) of the pleural effusion to the antibody treatment was 71.4% and the overall RR of measurable lesions was 23.8%. The median time-to-response for pleural effusion was 132 days. In conclusion, this study demonstrated a high R R to bevacizumab combination therapy for the MPE associated with non-squamous NSCLC. Therefore, bevacizumab therapy may be considered a therapeutic option for patients with non-squamous NSCLC who develop MPE.