Abstract 1342P
Background
Liver is a common metastatic site of lung cancer, and patients with liver metastases will progress rapidly. This study aims to access whether certain genomic features could predict the presence of liver metastasis.
Methods
A total of 253 patients with lung adenocarcinoma were divided into three groups: A (50 cases with liver metastases), B (88 cases without distal metastasis) and C (115 patients with other distal metastases). Their tumor tissue samples and matched peripheral blood were collected to perform next-generation sequencing of 1021 cancer-related genes. Their genomic features, including single-nucleotide variants (SNVs), small insertions and deletions (Indels), copy number variants (CNVs), structural variants (SVs), tumor mutation burden (TMB), were retrospectively reviewed. TMB was calculated as the number of somatic non-synonymous SNVs and Indels per Mb in the coding region.
Results
The number of mutations in group A was significantly higher than that in group B and C, with the median number of mutations of 9, 5, and 6, respectively (P =0.001, P=0.0001). The same trends were observed in terms of TMB (median: 6.24, 3, 3.84 muts/Mb; p=0.0022, p=0.0157), SNV (median: 8, 4, 5; p=0.0015, p=0.0005) and CNV (median: 1, 0, 0; p=0.0011, p=0.0002). There was no difference in the number of SV among three groups. Differential mutated genes were analyzed using Fisher’s exact test. The results showed that the mutation rate of PIK3CA was higher in group A than in group B and C (26%, 4.65%, 2.65%; P=0.0007, p=0.0001). TP53 mutation rate in group A and C was significantly higher than that in group B (72%, 60.18%, 39.53%; P=0.0003, P=0.0044).
Conclusions
These results suggested that PIK3CA mutation may play a non-negligible role in the development of liver metastasis. TP53 mutation may play a role in the distal metastasis of lung adenocarcinoma, but it is not a specific predictive biomarker for liver metastasis.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
R. Chen: Financial Interests, Personal, Full or part-time Employment: Geneplus-Beijing. All other authors have declared no conflicts of interest.