Tumor PD-L1 expression is associated with improved survival and lower recurrence risk in young women with oral cavity squamous cell carcinoma.

Young patients with oral cavity squamous cell carcinoma (OCSCC) are often recognized as a distinct epidemiological cohort. In this study, genomic and immune-based metrics were correlated with long-term outcomes for a young patient population treated at a single institution. A fully clinically annotated, retrospective cohort of 81 patients aged ≤45 years with OCSCC is described, and the impact of clinicopathological features on long-term survival outcomes is reported. Genomic and immune parameters were integrated utilizing a whole-exome sequencing and immunohistochemical approach among females in the cohort. It was found that young OCSCC patients had favorable outcomes (10-year disease-free survival 79.1%, overall survival 80.0%) regardless of sex, particularly if they presented with oral tongue primaries and early stage disease. While mutational analysis appeared similar to that of older patients with OCSCC who lack a smoking history, a comparatively high degree of PD-L1 expression and PD-1/L1 concordance (P=0.001) was found among young female OCSCC patients. Subjects with greater membranous PD-L1 positivity and the presence of tumor-infiltrating lymphocytes had a decreased risk of recurrence (P=0.01 and P=0.01, respectively) and improved survival (P=0.04 and P=0.03, respectively). These findings warrant further validation and support the investigation of immunotherapeutic approaches targeting PD-1/L1 interactions in young OCSCC patients.

Ligand-associated ERBB2/3 activation confers acquired resistance to FGFR inhibition in FGFR3-dependent cancer cells.

Somatic alterations of fibroblast growth factor receptors (FGFRs) have been described in a wide range of malignancies. A number of anti-FGFR therapies are currently under investigation in clinical trials for subjects with FGFR gene amplifications, mutations and translocations. Here, we develop cell line models of acquired resistance to FGFR inhibition by exposure of cell lines harboring FGFR3 gene amplification and translocation to the selective FGFR inhibitor BGJ398 and multitargeted FGFR inhibitor ponatinib. We show that the acquisition of resistance is rapid, reversible and characterized by an epithelial to mesenchymal transition and a switch from dependency on FGFR3 to ERBB family members. Acquired resistance was associated with demonstrable changes in gene expression including increased production of ERBB2/3 ligands, which were sufficient to drive resistance in the setting of FGFR3 dependency but not dependency on other FGFR family members. These data support the concept that activation of ERBB family members is sufficient to bypass dependency on FGFR3 and suggest that concurrent inhibition of these two pathways may be desirable when targeting FGFR3-dependent cancers.

Gene-expression data integration to squamous cell lung cancer subtypes reveals drug sensitivity.

BACKGROUND: Squamous cell lung cancer (SqCC) is the second most common type of lung cancer in the United States. Previous studies have used gene-expression data to classify SqCC samples into four subtypes, including the primitive, classical, secretory and basal subtypes. These subtypes have different survival outcomes, although it is unknown whether these molecular subtypes predict response to therapy. METHODS: Here, we analysed RNAseq data of 178 SqCC tumour samples and characterised the features of the different SqCC subtypes to define signature genes and pathway alterations specific to each subtype. Further, we compared the gene-expression features of each molecular subtype to specific time points in models of airway development. We also classified SqCC-derived cell lines and their reported therapeutic vulnerabilities. RESULTS: We found that the primitive subtype may come from a later stage of differentiation, whereas the basal subtype may be from an early time. Most SqCC cell lines responded to one of five anticancer drugs (Panobinostat, 17-AAG, Irinotecan, Topotecan and Paclitaxel), whereas the basal-type cell line EBC-1 was sensitive to three other drugs (PF2341066, AZD6244 and PD-0325901). CONCLUSION: Compared with the other three subtypes of cell lines, the secretory-type cell lines were significantly less sensitive to the five most effective drugs, possibly because of their low proliferation activity. We provide a bioinformatics framework to explore drug repurposing for cancer subtypes based on the available genomic profiles of tumour samples, normal cell types, cancer cell lines and data of drug sensitivity in cell lines.