Prognostic value of broad-spectrum keratin clones AE1/AE3 and CAM5.2 in small cell lung cancer patients undergoing pulmonary resection

Andrzej Badzio; Piotr Czapiewski; Adam Gorczyński; Kamila Szczepańska-Michalska; Johannes Haybaeck; Wojciech Biernat; Jacek Jassem

doi:10.18388/abp.2018_2773

Andrzej Badzio Centrum Radioterapii NU-MED Elbląg
Piotr Czapiewski 1Department of Pathology, Medical University of Gdansk, Poland; 2Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, Germany
Adam Gorczyński Department of Pathology, Medical University of Gdansk, Poland
Kamila Szczepańska-Michalska Copernicus Hospital, Gdansk, Poland
Johannes Haybaeck 1Department of Pathology, Medical Faculty, Otto-von-Guericke University Magdeburg, Germany; 2Institute of Pathology, Medical University of Graz, Austria; 3Department of Pathology, Neuropathology and Molecular Pathology, Medical University Innsbruck, Austria
Wojciech Biernat Department of Pathology, Medical University of Gdansk, Poland
Jacek Jassem Department of Oncology and Radiotherapy, Medical University of Gdansk, Poland

DOI: https://doi.org/10.18388/abp.2018_2773

Abstract

Introduction: Small cell lung carcinoma (SCLC) is an aggressive pulmonary neoplasm of neuroendocrine origin. Keratins form a large group of intermediate filaments, which are major structural proteins in epithelial cells and carcinomas. SCLC shows a wide spectrum of keratin expression, from very strong
to completely negative. A prognostic role of keratin expression in SCLC is unknown. Material and Methods: Tumor tissue microarray samples from a unique series of 82 SCLC patients who underwent pulmonary resection were stained with keratin specific antibodies AE1/AE3
and CAM5.2. The percentage o1f positively stained cells and their staining pattern (diffusely membranous, partially membranous and dot-like) were evaluated. The median expression value was used for the distinction between keratin-negative and -positive patients. Overall survival in respective groups was compared using the log-rank test. Multivariate Cox proportional hazards regression analysis was performed adjusting for age, gender, tumor site, tumor stage, and tumor histology. Results: edian expression of AE1/AE3 and CAM5.2 was 80% and 90%, respectively. Five cases were completely negative for AE1/AE3 and three for Cam5.2. Median overall survival for patients with stronger and weaker AE1/AE3 staining was 24.7 and 13.8 months, respectively (p=0.019).
There was no difference in survival in relation to the CAM5.2 expression (p=0.44). In multivariate analysis adjusted for CAM5.2, T and N stage, gender and age at diagnosis, stronger AE1/AE3 expression was an independent predictor of increased survival (HR 0.50; 95% CI, 0.27–0.94; p=0.031). Conclusion: High expression of AE1/AE3 is a favorable prognostic factor in surgically treated SCLC. The applicability of this finding to a typical patient population treated with non-surgical methods warrants further studies.