Drug-induced RAF dimerization is independent of RAS mutation status and does not lead to universal MEK dependence for cell survival in head and neck cancers

Precision drugging of the MAPK pathway in head and neck cancer

The mitogen-activating protein kinase (MAPK) pathway is central for cell proliferation, differentiation, and senescence. In human, germline defects of the pathway contribute to developmental and congenital head and neck disorders. Nearly 1/5 of head and neck squamous cell carcinoma (HNSCC) harbors MAPK pathway mutations, which are largely activating mutations. Yet, previous approaches targeting the MAPK pathway in HNSCC were futile. Most recent clinical evidences reveal remarkable, or even exceptional pharmacologic vulnerabilities of MAPK1-mutated, HRAS-mutated, KRAS-germline altered, as well as BRAF-mutated HNSCC patients with various targeted therapies, uncovering diverse opportunities for precision drugging this pathway at multiple “genetically condemned” nodes. Further, recent patient tumor omics unveil novel effects of MAPK aberrations on direct induction of CD8⁺ T cell recruitment into the HNSCC microenvironment, providing evidences for future investigation of precision immunotherapy for this large subset of patients. MAPK pathway-mutated HNSCC should warrant precision therapy assessments in vigorous manners.

Toward the use of precision medicine for the treatment of head and neck squamous cell carcinoma

Precision medicine is a new strategy that aims at preventing and treating human diseases by focusing on individual variations in people's genes, environment and lifestyle. Precision medicine has been used for cancer diagnosis and treatment and shows evident clinical efficacy. Rapid developments in molecular biology, genetics and sequencing technologies, as well as computational technology, has enabled the establishment of "big data", such as the Human Genome Project, which provides a basis for precision medicine. Head and neck squamous cell carcinoma (HNSCC) is an aggressive cancer with a high incidence rate and low survival rate. Current therapies are often aggressive and carry considerable side effects. Much research now indicates that precision medicine can be used for HNSCC and may achieve improved results. From this perspective, we present an overview of the current status, potential strategies, and challenges of precision medicine in HNSCC. We focus on targeted therapy based on cell the surface signaling receptors epidermal growth factor receptor (EGFR), vascular endothelial growth factor (VEGF) and human epidermal growth factor receptor-2 (HER2), and on the PI3K/AKT/mTOR, JAK/STAT3 and RAS/RAF/MEK/ERK cellular signaling pathways. Gene therapy for the treatment of HNSCC is also discussed.

Leveraging Genomics for Head and Neck Cancer Treatment

The genomic landscape of head and neck squamous cell carcinoma (HNSCC) has been recently elucidated. Key epigenetic and genetic characteristics of this cancer have been reported and substantiated in multiple data sets, including those distinctive to the growing subset of human papilloma virus (HPV)-associated tumors. This increased understanding of the molecular underpinnings of HNSCC has not resulted in new approaches to treatment. Three Food and Drug Administration-approved molecular targeting agents are currently available to treat recurrent/metastatic disease, but these have exhibited efficacy only in subsets of HNSCC patients, and thus surgery, chemotherapy, and/or radiation remain as standard approaches. The lack of predictive biomarkers to any therapy represents an obstacle to achieving the promise of precision medicine. This review aims to familiarize the reader with current insights into the HNSCC genomic landscape, discuss the currently approved and promising molecular targeting agents under exploration in laboratories and clinics, and consider precision medicine approaches to HNSCC.

Incorporation of Next-Generation Sequencing into Routine Clinical Care to Direct Treatment of Head and Neck Squamous Cell Carcinoma

PURPOSE

The clinical impact of next-generation sequencing (NGS) in patients with head and neck squamous cell carcinoma (HNSCC) has not been described. We aimed to evaluate the clinical impact of NGS in the routine care of patients with HNSCC and to correlate genomic alterations with clinical outcomes.

EXPERIMENTAL DESIGN

Single-center study examining targeted NGS platform used to sequence tumor DNA obtained from 213 HNSCC patients evaluated in outpatient head and neck oncology clinic between August 2011 and December 2014. We correlated tumor genomic profiling results with clinical outcomes.

RESULTS

PI3K/RTK pathway activation occurred frequently [activating PIK3CA mutation or amplification (13%), PTEN inactivation (3%), RAS activation (6%), EGFR or ERBB2 activation (9%)]. Alterations in pathways affecting cell-cycle regulation [CCND1 amplification (9%), CDKN2A inactivation (17%), BRCA2 inactivation (2%)] and squamous differentiation [NOTCH1 inactivation (8%) andEP300 inactivation (6%)] were identified. PIK3CA amplification (n = 43), not PIK3CA mutation, was associated with significantly poorer progression-free survival (P = 0.0006). Oncogenic RAS mutations (n = 13) were associated with significantly poorer progression-free survival (P = 0.0001) and lower overall survival (P = 0.003). Eight patients with advanced, treatment-refractory HNSCC enrolled on clinical trials matched to tumor profiling results, and 50% achieved a partial response.

CONCLUSIONS

Incorporation of NGS clinical assays into the routine care of patients with HNSCC is feasible and may readily facilitate enrollment into clinical trials of targeted therapy with a higher likelihood of success. Data can be utilized for discovery of genomic biomarkers of outcome. PIK3CA amplification and RAS mutations were frequently identified and associated with poorer prognosis in this cohort. Clin Cancer Res; 22(12); 2939-49. ©2016 AACR.