High tumor mutational burden predicts survival and responses to ICI immunotherapy in a cancer-dependent manner

Objective High tumor mutational burden (TMB) is a promising biomarker for patients with immunotherapy in certain types of solid tumors. This article focuses on exploring possible universally optimal cutoffs of TMB for predicting immune checkpoint inhibitors (ICIs) response and prognosis for eight types of cancers. Methods The present study collected eight types of tumors including 2767 patients receiving immune checkpoint inhibitors (ICIs) treatment and 14862 patients without ICI treatment. We tried to explore optimal cutoffs of TMB in each type of tumor via selecting several possible cutoffs of TMB including 10mut/Mb, top 10%, 20%, and 30% of TMB within each histology. Results We found that there was a significant difference in TMB values between ICI-treated and non-ICI-treated groups. The cutoff of TMB appropriate for predicting response rates, progression rates, and survival rates was varied in ICI therapy patients. Moreover, the optimal cutoff of TMB for predicting progression-free survival and overall survival in different types of the tumor was also quietly different. Conclusion Our current study suggested that TMB predicts prognosis and responses to ICI treatment in a cancer-dependent manner.