ABSTRACT
ObjectiveTo explore the clinical application of molecular classification in endometrial cancers with the next generation sequencing （NGS）. MethodsTotally 112 cases of endometrial carcinoma diagnosed by pathology in The Sun Yat-sen University Cancer Center were collected. All of them were tested by hybridized-capture second-generation sequencing based on 1，021 gene panel. The molecular variation spectrum of each subtype and its relationship between the clinicopathological features were analyzed. ResultsThe cases were distributed as follows： 8 （7.1%） POLE mutation， 34 （30.4%） mismatch repair deficient， 26 （23.2%） TP53 mutation， 44 （39.3%） non-specific molecular profile. The median tumor mutation burden was respectively 252.0， 38.4， 5.8 and 5.4 Muts/Mb. There were no significantly differences among four subtypes in clinicopathological features such as age， histological grade， lymph node metastasis and clinical stage. PTEN （75.5%）， PIK3CA （66.7%）， ARID1A （55.9%）， TP53 （40.2%）， NF1 （29.4%） were the most common mutations in endometrial cancers. ConclusionsThe utilization of NGS in endometrial cancers can simultaneously identify molecular subgroups， screen Lynch syndrome and obtain molecular variation spectrum， which can provide guidance for immunotherapy and targeted therapy， contribute to further accumulation and exploration of molecular genetic characteristics.
ABSTRACT
Purpose@#Current variability in methods for tumor mutational burden (TMB) estimation and reporting demonstrates the urgent need for a homogeneous TMB assessment approach. Here, we compared TMB distributions in different cancer types using two customized targeted panels commonly used in clinical practice. @*Materials and Methods@#TMB spectra of 295- and 1021-gene panels in multiple cancer types were compared using targeted next-generation sequencing (NGS). The TMB distributions across a diverse cohort of 2,332 cancer cases were then investigated for their associations with clinical features. Treatment response data were collected for 222 patients who received immune-checkpoint inhibitors (ICIs) and their homologous recombination DNA damage repair (HR-DDR) and programmed death-ligand 1 (PD-L1) expression were additionally assessed and compared with the TMB and response rate. @*Results@#The median TMB between gene panels was similar despite a wide range in TMB values. The highest TMB was 8 and 10 in patients with squamous cell carcinoma and esophageal carcinoma according to the classification of histopathology and cancer types, respectively. Twenty-three out of 103 patients (22.3%) were HR-DDR‒positive and could benefit from ICI therapy; out of those 23 patients, seven patients had high TMB (p=0.004). Additionally, PD-L1 expression was not associated with TMB or treatment response among patients receiving ICIs. @*Conclusion@#Targeted NGS assays demonstrated the ability to evaluate TMB in pan-cancer samples as a tool to predict response to ICIs. In addition, TMB integrated with HR-DDR‒positive status could be a significant biomarker for predicting ICI response in patients.