Comparison of Clinically Relevant Mutation Profiles Between Preoperative Biopsy and Corresponding Surgically Resected Specimens in Japanese Patients With Non-Small-cell Lung Cancer by Amplicon-based Massively Parallel Sequencing.

Background: Amplicon-based massively parallel sequencing (MPS) is an effective platform for identifying clinically actionable mutations across many genes in limited amounts of tissue. Most lung cancers are diagnosed and staged using small tissue samples obtained by transbronchial biopsy (TBB). To determine whether the mutations in TBB specimens detected by amplicon-based MPS reflect those present in the tumors, we compared the mutational profiles of preoperative TBB specimens and corresponding surgically resected specimens.

Patients And Methods: Fresh-frozen primary tumor specimens from non-small-cell lung cancer patients (n = 46) obtained preoperatively by TBB and during surgical resection were analyzed. The concordance of mutations detected by amplicon-based MPS in the 2 sample types was investigated, and the allele frequency of the mutations common to both specimens from the same patient was determined.

Results: An initial assessment of DNA quantity revealed that 46% of the TBB specimens (21 of 46) had less than the lower limit for amplicon-based MPS. These 21 TBB specimens were consequently omitted from the analysis. Of the 29 mutations detected in the TBB and/or surgically resected specimens from 25 patients, 23 were present in both samples, for a concordance rate of 79%.

Conclusion: Amplicon-based MPS with TBB specimens approximately reflects clinically relevant tumor mutation profiles. However, the rate of TBB specimens with sufficient DNA quantity for amplicon-based MPS was only around 50%. Therefore, surgically resected specimens have a valuable role in exploratory and comprehensive genomic profiling.