Spanish Lung Cancer Biomarker Testing Registry (Lungpath): Descriptive Analysis Focus in ALK Traslocation Results

Abstract

Background Oncogenic ALK gene rearrangements are found in approximately 4% of non-small cell lung cancer (NSCLC). Treatment options such as ALK tyrosine kinase inhibitors lead to improved progression free survival and overall survival. Thus, biomarker testing on pathology specimens is an essential requirement to properly treat lung cancer (LC) patients. LungPath is an on-line tool developed by the Spanish Society of Pathology (SEAP) with free and voluntary participation of differents Departments of Pathology to registry, monitor and trace biomarker results in clinical practice. After initial data reclutation step, first objective is to realize a descriptive analysis of LungPath focusing on ALK traslocation testing.

Method Descriptive analysis of the LungPath registry. Biomarkers determinations of LC patients were collected from March 2018 to January 2019, from 38 Spanish Departments of Pathology.

Result Based on this real clinical practice database, 19.332 biomarkers were tested over a total of 4.773 samples from LC patients. Small lung biopsies (60%), surgical resection specimen (16,3%) and cell block cytology (10,7%) were the mainly used samples in addition to fine needle aspiration cytology (5,1%), blood (2,5%) and other non lung biopsies (5,4%). NSCLC accounts for 95,1% of cases, principally adenocarcinoma (66%), squamous cell carcinoma (SCC) (19%), NOS (not otherwise specified, 6,1%), large cell neuroendocrine carcinoma (3,7%) and large cell carcinoma accounting for 0,3%. In non-squamous samples, ALK traslocation was one of the most frequently analyzed biomarker (80,1%), on the other hand, in SCC, ALK traslocation was shortly analyzed (53,1%), being PD-L1 expression the main biomarker realized (73,6%). From the adenocarcinoma samples were ALK was tested the positivity rate was 3,4%, whereas, 2,4% were not valit determinations due to several reasons. Used techniques plus further information has also been analyzed.

Conclusion Development of central biomarker databases, such as Lungpath, provide an opportunity to registry clinical practice data and in the future could be an useful tool to monitor, correlate results between different centers and improve the available knowledge regarding biomarkers in LC. According the international guidelines, EGFR mutation and ALK traslocation should be tested in all advanced NSCLC overall in lung adenocarcinoma. ALK traslocation was one of the main biomarkers tested in our database with 3,4% traslocation rate, similar with the literature reports.