Endocrine Pathology

, Volume 25, Issue 2, pp 151–164

Unraveling Tumor Grading and Genomic Landscape in Lung Neuroendocrine Tumors

Authors

    • Department of Pathology and Laboratory MedicineFondazione IRCCS Istituto Nazionale dei Tumori
    • Department of Biomedical and Clinical Sciences Luigi SaccoUniversità degli Studi
    • Dipartimento di Patologia Diagnostica e LaboratorioFondazione IRCCS Istituto Nazionale dei Tumori
  • Mauro Papotti
    • Department of OncologyUniversità degli Studi of Turin at San Luigi Hospital
  • Guido Rindi
    • Institute of Anatomic PathologyGemelli Hospital and Università Cattolica del Sacro Cuore
  • Aldo Scarpa
    • Department of Pathology and DiagnosticsUniversità degli Studi
    • ARC-NET Research CentreUniversità degli Studi
Article

DOI: 10.1007/s12022-014-9320-0

Cite this article as:
Pelosi, G., Papotti, M., Rindi, G. et al. Endocr Pathol (2014) 25: 151. doi:10.1007/s12022-014-9320-0

Abstract

Currently, grading in lung neuroendocrine tumors (NETs) is inherently defined by the histological classification based on cell features, mitosis count, and necrosis, for which typical carcinoids (TC) are low-grade malignant tumors with long life expectation, atypical carcinoids (AC) intermediate-grade malignant tumors with more aggressive clinical behavior, and large cell NE carcinomas (LCNEC) and small cell lung carcinomas (SCLC) high-grade malignant tumors with dismal prognosis. While Ki-67 antigen labeling index, highlighting the proportion of proliferating tumor cells, has largely been used in digestive NETs for assessing prognosis and assisting therapy decisions, the same marker does not play an established role in the diagnosis, grading, and prognosis of lung NETs. Next generation sequencing techniques (NGS), thanks to their astonishing ability to process in a shorter timeframe up to billions of DNA strands, are radically revolutionizing our approach to diagnosis and therapy of tumors, including lung cancer. When applied to single genes, panels of genes, exome, or the whole genome by using either frozen or paraffin tissues, NGS techniques increase our understanding of cancer, thus realizing the bases of precision medicine. Data are emerging that TC and AC are mainly altered in chromatin remodeling genes, whereas LCNEC and SCLC are also mutated in cell cycle checkpoint and cell differentiation regulators. A common denominator to all lung NETs is a deregulation of cell proliferation, which represents a biological rationale for morphologic (mitoses and necrosis) and molecular (Ki-67 antigen) parameters to successfully serve as predictors of tumor behavior (i.e., identification of pathological entities with clinical correlation). It is envisaged that a novel grading system in lung NETs based on the combined assessment of mitoses, necrosis, and Ki-67 LI may offer a better stratification of prognostic classes, realizing a bridge between molecular alterations, morphological features, and clinical behavior.

Keywords

LungNeuroendocrineTumorsCarcinomaCarcinoidTypicalAtypicalLCNECSCLCGradingNext generation sequencingCell cycleChromatinRemodelingPrognosisSurvival

Copyright information

© Springer Science+Business Media New York 2014