[Application value of whole exon sequencing and immune related indicators in the precision treatment of oral squamous cell carcinoma].

OBJECTIVE

To explore the significance and feasibility of whole exon sequencing and immune related indexes in personalized precision treatment of oral squamous cell carcinoma (OSCC).

METHODS

We retrospectively screened the patients who underwent surgery for oral cancer in Peking University Hospital of Stomatology and underwent genetic and immune biomarkers tests between January 2021 and June 2022. Combined with the clinicopathological characteristics of patients, potential targeted drugs and immunotherapy drugs were screened to evaluate the possibility of gene testing benefiting OSCC. The main evaluation indicators included the number of gene mutations, combined positive score (CPS), tumor mutation burden (TMB), microsatellite sequence status and human leukocyte antigen B (HLA-B) locus. Excel was used for statistical analysis.

RESULTS

A total of 10 patients were enrolled and 9 were included in this study, including 6 males and 3 females, with an average age of (55.44±9.59) years. The tumor location was buccal (5 cases), tongue (3 cases) and gingival (1 case). The results of genetic testing showed that 3 (33.3%) patients had no gene mutations in the tumor tissue, 5 (55.6%) patients had unique TP53 gene mutations, and 1 (11.1%) patient had TP53 and CHEK1 mutations. However, no drugs were available for targeted therapy of the mutated genes. The genetic tumor gene testing results showed that no genetic tumor gene was found in all the patients, suggesting that OSCC had a low possibi-lity of hereditary tumor. In terms of immune efficacy related markers, CPS test results showed that 8 patients had CPS≥1. TMB detection results showed that the median value of TMB value was 0.72 mutations/Mb, and the range was 0 to 4.32 mutations/Mb. The negative and positive control results of microsatellite sequence status were consistent, indicating that all the tumor tissues detected were microsatellite stability. The results of HLA-B detection showed that only one patient had B62 gene mutation, suggesting that the B44 and B62 related genotypes of HLA-B in OSCC tissue samples were low.

CONCLUSION

The present results do not support the wide application and promotion of genetic testing and immune related indexes in OSCC.