Expression and Prognostic Significance of c-Myc, ALK, ROS1, BRAF, and PD-L1 Among Patients With Non-Small Cell Lung Cancer

Predictive value and molecular correlates of MYC immunohistochemistry and copy number gain in non-small cell lung carcinomas treated with immunotherapy

OBJECTIVES

Accurately predicting which patients diagnosed with non-small cell lung cancer (NSCLC) will respond to immunotherapy remains a clinical challenge. This study aims to determine the associations between MYC immunoreactivity, MYC copy number gain (CNG), driver mutations and survival following immunotherapy treatment, to provide insight into whether clinical MYC assessment may have predictive value.

MATERIALS AND METHODS

MYC copy number status was determined in 82 patients with NSCLC treated with immunotherapy, and MYC immunohistochemistry (IHC) was performed on 80 of these cases. MYC staining in ≥ 40 % of tumor cells was considered positive. Driver gene alterations, PD-L1 status and survival outcomes were assessed through retrospective chart review. Overall survival (OS) and progression free survival (PFS) were calculated from the date of immunotherapy initiation.

RESULTS

Nine (11 %) of 82 cases had MYC CNG and 56 (70 %) of the 80 immunostained cases were positive for MYC. MYC CNG was significantly associated with STK11 mutation (P=0.023), whereas positive MYC IHC was significantly associated with KRAS mutation (P=0.0076) and current/former smoking (P=0.0007). MYC CNG and positive MYC IHC were not significantly associated with each other (P=0.42), or with PD-L1 ≥ 1 % (MYC CNG: P=0.10; MYC IHC: P=0.09). Positive MYC IHC and PD-L1 ≥ 1 % were both significant predictors of OS (MYC: HR 2.7, 95 % CI 1.1-6.4, P=0.026; PD-L1: HR 0.33, 95 % CI 0.15-0.72, P=0.0055). MYC IHC positive/PD-L1 < 1 % cases had the shortest OS (median 230 versus 918 days, P=0.00069) and PFS (median 84 versus 254 days, P=0.0087). MYC CNG was not associated with OS or PFS.

CONCLUSION

We find that positive MYC IHC is an independent predictor of shorter OS after immunotherapy treatment, with MYC positive/PD-L1 < 1 % status predictive of particularly poor immunotherapy response. We identify positive MYC IHC as a feature of possible relevance to NSCLC treatment selection and of interest for future therapy development.

Integrated analysis of bulk and single-cell RNA-seq reveals the role of MYC signaling in lung adenocarcinoma

MYC is one of the well-known oncogenes, and its important role in cancer still remains largely unknown. We obtained lung adenocarcinoma (LUAD) multi-omics data including genome, transcriptome, and single-cell sequencing data from multiple cohorts. We calculated the GSVA score of the MYC target v1 using the ssGSEA method, and obtained the genes highly correlated with this score by Spearman correlation analysis. Subsequent hierarchical clustering divided these genes into two gene sets highly associated with MYC signaling (S1 and S2). Unsupervised clustering based on these genes divided the LUAD samples into two distinct subgroups, namely, the MYC signaling inhibition group (C1) and activation group (C2). The MCP counter package in R was used to assess tumor immune cell infiltration abundance and ssGSEA was used to calculate gene set scores. The scRNA-seq was used to verify the association of MYC signaling to cell differentiation. We observed significant differences in prognosis, clinical characteristics, immune microenvironment, and genomic alterations between MYC signaling inhibition and MYC signaling activation groups. MYC-signaling is associated with genomic instability and can mediate the immunosuppressive microenvironment and promote cell proliferation, tumor stemness. Moreover, MYC-signaling activation is also subject to complex post-transcriptional regulation and is highly associated with cell differentiation. In conclusion, MYC signaling is closely related to the genomic instability, genetic alteration and regulation, the immune microenvironment landscape, cell differentiation, and disease survival in LUAD. The findings of this study provide a valuable reference to revealing the mechanism of cancer-promoting action of MYC in LUAD.