SCLC Subtypes Defined by ASCL1, NEUROD1, POU2F3, and YAP1: A Comprehensive Immunohistochemical and Histopathologic Characterization
Journal
Journal of Thoracic Oncology
Journal Volume
15
Journal Issue
12
Pages
1823-1835
Date Issued
2020
Author(s)
Baine M.K.
Lai W.V.
Egger J.V.
Jungbluth A.A.
Daneshbod Y.
Beras A.
Spencer R.
Lopardo J.
Bodd F.
Montecalvo J.
Sauter J.L.
Chang J.C.
Buonocore D.J.
Travis W.D.
Sen T.
Poirier J.T.
Rudin C.M.
Rekhtman N.
Abstract
Introduction: Recent studies have identified subtypes of small cell lung carcinoma (SCLC) defined by the RNA expression of ASCL1, NEUROD1, POU2F3, and YAP1 transcriptional regulators. There are only limited data on the distribution of these markers at the protein level and associated pathologic characteristics in clinical SCLC samples. Methods: The expression of ASCL1, NEUROD1, POU2F3, and YAP1 was analyzed by immunohistochemistry in 174 patient samples with SCLC. Subtypes defined by these markers were correlated with histologic characteristics, expression of classic neuroendocrine markers (synaptophysin, chromogranin A, CD56, INSM1), and other SCLC markers, including the neuroendocrine phenotype-associated markers TTF-1 and DLL3. Results: ASCL1 and NEUROD1 expression had the following distribution: (1) 41% ASCL1+/NEUROD1?; (2) 37% ASCL1+/NEUROD1+; (3) 8% ASCL1?/NEUROD1+; and (4) 14% ASCL1?/NEUROD1?. On the basis of their relative expression, 69% of cases were ASCL1-dominant and 17% were NEUROD1-dominant. POU2F3 was expressed in 7% of SCLC and was mutually exclusive of ASCL1 and NEUROD1. YAP1 was expressed at low levels, primarily in combined SCLC, and was not exclusive of other subtypes. Both ASCL1-dominant and NEUROD1-dominant subtypes were associated with neuroendocrine markerhigh/TTF-1high/DLL3high profile, whereas POU2F3 and other ASCL1/NEUROD1 double-negative tumors were neuroendocrine markerlow/TTF-1low/DLL3low. Conclusions: This is the first comprehensive immunohistochemical and histopathologic analysis of novel SCLC subtypes in patient samples. We confirm that ASCL1/NEUROD1 double-negative tumors represent a distinct neuroendocrine-low subtype of SCLC, which is either uniquely associated with POU2F3 or lacks a known dominant regulator. The expression profiles of these markers appear more heterogeneous in native samples than in experimental models, particularly with regard to the high prevalence of ASCL1/NEUROD1 coexpression. These findings may have prognostic and therapeutic implications and warrant further clinical investigation. ? 2020 International Association for the Study of Lung Cancer
Subjects
ASCL1; NEUROD1; Neuroendocrine; POU2F3; Small cell lung carcinoma; YAP1
SDGs
Other Subjects
CD56 antigen; chromogranin A; homeobox protein Nkx 2.1; insulinoma associated protein 1; neurogenic differentiation factor; octamer transcription factor; protein DLL3; protein POU2F3; synaptophysin; transcription factor Mash1; transcription factor Yap1; tumor marker; unclassified drug; ASCL1 protein, human; basic helix loop helix transcription factor; INSM1 protein, human; octamer transcription factor; POU2F3 protein, human; repressor protein; aged; Article; cancer patient; cancer prognosis; cancer tissue; controlled study; female; histology; histopathology; human; human tissue; immunohistochemistry; male; neuroendocrinology; pathogenesis; phenotype; priority journal; protein expression; small cell lung cancer; tissue microarray; immunohistochemistry; lung tumor; prognosis; small cell lung cancer; Basic Helix-Loop-Helix Transcription Factors; Humans; Immunohistochemistry; Lung Neoplasms; Octamer Transcription Factors; Prognosis; Repressor Proteins; Small Cell Lung Carcinoma
Publisher
Elsevier Inc.
Type
journal article