Investigation of tumor mutation burden using the comprehensive genomic profiling data of vulvar and vaginal malignant tumors: an observational study using C-CAT database.

BACKGROUND

This study aimed to reveal the gene alteration and tumor mutation burden (TMB) statuses of vulvar and vaginal malignant tumors in Japan.

METHODS

We investigated the cancer genomic profiling (CGP) data of 79 patients with vulvar and vaginal cancers. These data were obtained from the Center for Cancer Genomics and Advanced Therapeutics (C-CAT).

RESULTS

None of the patients had high microsatellite instability. Although 21.9% of the patients with vulvar and vaginal squamous cell carcinoma (SCC) had high TMB, those with other histological types did not. The top single-nucleotide variants (SNVs) in SCC were TERT, TP53, CDKN2A, KMT2D, and NOTCH1. The frequencies of ATRX and PBRM1 were significantly higher in TMB-high SCC than in non-TMB-high SCC.

CONCLUSION

SCC of the vulva and vagina is expected to have high TMB, and gene alteration status differed between TMB-high and non-TMB-high groups.