Combined Large Cell Neuroendocrine Carcinomas of the Lung: Integrative Molecular Analysis Identifies Subtypes with Potential Therapeutic Implications.

BACKGROUND: Combined large cell neuroendocrine carcinoma (CoLCNEC) is given by the association of LCNEC with adeno or squamous or any non-neuroendocrine carcinoma. Molecular bases of CoLCNEC pathogenesis are scant and no standardized therapies are defined. METHODS: 44 CoLCNECs: 26 with adenocarcinoma (CoADC), 7 with squamous cell carcinoma (CoSQC), 3 with small cell carcinoma (CoSCLC), 4 with atypical carcinoid (CoAC) and 4 napsin-A positive LCNEC (NapA+), were assessed for alterations in 409 genes and transcriptomic profiling of 20,815 genes. RESULTS: Genes altered included TP53 (n = 30), RB1 (n = 14) and KRAS (n = 13). Targetable alterations included six KRAS G12C mutations and ALK-EML4 fusion gene. Comparison of CoLCNEC transcriptomes with 86 lung cancers of pure histology (8 AC, 19 ADC, 19 LCNEC, 11 SCLC and 29 SQC) identified CoLCNEC as a separate entity of neuroendocrine tumours with three different molecular profiles, two of which showed a non-neuroendocrine lineage. Hypomethylation, activation of MAPK signalling and association to immunotherapy signature specifically characterized each of three CoLCNEC molecular clusters. Prognostic stratification was also provided. CONCLUSIONS: CoLCNECs are an independent histologic category. Our findings support the extension of routine evaluation of KRAS mutations, fusion genes and immune-related markers to offer new perspectives in the therapeutic management of CoLCNEC.

Gela histological scoring system for post-treatment biopsies of patients with gastric MALT lymphoma is feasible and reliable in routine practice.

The International Extranodal Lymphoma Study Group (IELSG) promoted this study to determine the inter-observer agreement in the application of the Groupe d' Etude des Lymphomes de l' Adulte (GELA) histological scoring system for evaluating residual disease in post-treatment gastric biopsies of patients with gastric Mucosa-Associated Lymphoid Tissue (MALT) lymphoma (GML). Twenty-one patients with Helicobacter pylori -associated GML and treated with anti-H. pylori therapies were considered. A total of 154 biopsy sets from follow-up endoscopic procedures after H. pylori eradication were examined independently by seven pathologists from four European countries, following histological criteria suggested by the GELA scoring system. The overall concordance rate was 83% with a kappa value of 0·64, indicating a significant agreement among the seven observers. Most non-concordant responses clustered across the border of complete remission (CR) and probable minimal residual disease (pMRD), a distinction that does not imply critical clinical impact. Accordingly, when the analysis considered CR/pMRD as a single entity, the responses showed an overall concordance rate of 89% with kappa value of 0·83, thus indicating a high degree of inter-observer agreement. This study provides additional validation of the GELA histological grading system. This scheme can therefore be recommended in routine practice and deserves to be used in prospective clinical trials.

Natural history of imatinib-naive GISTs: a retrospective analysis of 929 cases with long-term follow-up and development of a survival nomogram based on mitotic index and size as continuous variables.

Gastrointestinal stromal tumor (GIST) natural history per se has not been extensively investigated yet, with most data being drawn from large studies with a relevant referral bias. Hence, the estimation of prognosis still remains a critical issue. We retrospectively evaluated 929 GISTs resected between 1980 and 2000 in 35 Italian institutions. A total of 526 patients were found to be suitable for refining risk assessment through the development of a survival nomogram. Median follow-up was 126 months. On testing for potential prognostic parameters, age, tumor site, size, and mitotic index proved to be predictors of OS on both univariable and multivariable Cox model analyses, whereas necrosis and cytonuclear atypia were significant on univariable analysis only. The discriminative ability of the model, including the parameters selected after a backward procedure (C=0.72), improved compared with the National Institutes of Health 2002 (C=0.64) and the National Comprehensive Cancer Network 2007 (C=0.63). On the basis of these data we developed a prognostic nomogram for survival that considers site, size, and mitotic index as continuous variables, providing estimates stratified for patients aged ≤65 and >65 years. This nomogram is a tool based on survival. It overcomes problems that result from artificial categorization of continuous variables. We believe that in the future this should also be attempted by nomograms based on the risk of relapse.