Lung cancer-associated T cell repertoire as potential biomarker for early detection of stage I lung cancer.

BACKGROUND: Early detection of lung cancer in asymptomatic patients remains challenging, especially for stage I. Considering the substantial interaction with tumor immunogenicity, we hypothesized that lung cancer-associated TCR (LC-aTCR) may serve as potential biomarker in early detection of stage I lung cancer. METHODS: Individuals who received low-dose computed tomography (LDCT) screening were enrolled in the study. Surgical tissues and peripheral blood specimens were collected and performed with DNA-based T cell repertoire (TCR) sequencing. The motif-based algorithm was used to deconstruct specific lung cancer-associated TCRs (LC-aTCRs). RESULTS: A total of 146 individuals participating in the real-world LDCT screening project were enrolled in this study, including 52 patients with pathologically-confirmed stage I lung cancer and 94 non-cancer controls. We developed a motif-based algorithm to define 80 LC-aTCRs in the training cohort. Moreover, in the validation cohort, high sensitivity and specificity was showed in stage I lung cancer with 72% and 91% respectively, and the AUC of the ROC curve was 0.91 (95% CI: 0.85 ∼ 0.96). CONCLUSION: This work provides inspiration for stage I lung cancer detection by using blood TCR profiling data. The combination of TCR-based assay and routine screening deserves further testing in larger cohorts.

The prevalence and prognostic value of KRAS co-mutation subtypes in Chinese advanced non-small cell lung cancer patients.

OBJECTIVE: KRAS mutation plays a critical role in the initiation and development of non-small cell lung cancer (NSCLC). KRAS-mutant patients exhibit diverse response to chemotherapy. KRAS co-mutation subtypes and their prognosis value in advanced Chinese NSCLC patients remain largely elusive. METHODS: A total of 1126 Chinese advanced NSCLC patients from Xiangya hospital were screened by capture-based ultra-deep sequencing for KRAS mutation between January 2015 and December 2016. Survival analyses were performed using Kaplan-Meier analysis. RESULTS: Among the patients screened, 84 cases were detected with KRAS mutation (7.5%). All of them were non-squamous NSCLC and received pemetrexed plus platinum as the first-line treatment. The most frequent KRAS co-mutation genes were TP53 (29%), TP53/LKB1 (19%), and LKB1 (14%). Our data revealed that patients with KRAS co-mutation had poorer prognosis in comparison with those harboring single KRAS mutation. Furthermore, patients with KPL (KRAS mutated with TP53 and LKB1) subtype, which was a novel subtype, had the shortest progression-free survival (PFS) in all types of KRAS co-mutation patients (P < .0001). The PFS and overall survival (OS) of patients with KRASG12D mutation were inferior than those with KRASG12C mutation or KRASG12V mutation. Patients in KRASG>T type had significantly longer survival than those in KRASG>C type or KRASG>A type. CONCLUSION: Our study revealed that concurrent genomic alterations can further stratify KRAS-mutant lung adenocarcinoma patients into various subgroups with distinctive therapeutic responses and differential survival outcomes. The KPL is a novel and less responsive subtype among KRAS-mutated NSCLC, and further investigation of effective treatment for this subtype is warranted.