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Tumor mutational burden on cytological samples: A pilot study
Author(s) -
Pepe Francesco,
Pisapia Pasquale,
Gristina Valerio,
Rocco Danilo,
Micheli Mariacarolina,
Micheli Pietro,
Iaccarino Antonino,
Tufano Rossella,
Gragnano Gianluca,
Russo Gianluca,
De Luca Caterina,
Sgariglia Roberta,
Nacchio Mariantonia,
Girolami Ilaria,
Eccher Albino,
Russo Antonio,
Troncone Giancarlo,
Malapelle Umberto
Publication year - 2021
Publication title -
cancer cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.29
H-Index - 57
eISSN - 1934-6638
pISSN - 1934-662X
DOI - 10.1002/cncy.22400
Subject(s) - medicine , amplicon , lung cancer , oncology , biomarker , deep sequencing , cancer , computational biology , polymerase chain reaction , genome , biology , genetics , gene
Background Immune‐checkpoint inhibitors (ICIs) represent an important treatment option for patients who have advanced stage non–small cell lung cancer (NSCLC). Currently, evaluation of the expression level of programmed death‐ligand 1 (PD‐L1) has proven highly successful as a positive predictive biomarker for ICIs. In addition to PD‐L1, other promising predictive biomarkers are emerging, including high tumor mutational burden (TMB‐H). However, measuring TMB‐H remains challenging for several reasons, among which is the difficulty in obtaining adequate tissue material from NSCLC patients. There are no data in the current literature regarding the possibility of adopting cell blocks (CBs) for TMB evaluation; therefore, our goal was to evaluate the feasibility of analyzing TMB on CBs. Methods For evaluation of differences in run metric parameters, 8 pairs of histological and CB samples from patients with NSCLC were analyzed using the Oncomine Tumor Mutational Load Assay on Ion Torrent S5 GS next‐generation sequencing (NGS) platform. Results Most CBs (6/8, 75.0%) were successfully analyzed by adopting the broad NGS panel approach. CBs provided results similar to those obtained on histological matched specimens in terms of median total reads (7207048.80 vs 7558817.80), median mapped reads (7075753.83 vs 7513822.00), median read lengths (115.50 vs. 113.00), median percentage of reads on‐target (97.49% vs. 98.45%), median average reads per amplicon (454.67 vs 476.14), and median uniformity of amplicon coverage (83.52% vs 84.13%). Conclusion In this pilot study, we demonstrated the technical feasibility of assessing TMB on CBs.