Researchers document molecular tumor subtypes of head and neck cancer
Head and neck squamous cell carcinoma (HNSCC) is the seventh most common form of cancer in the United States. However, other than an association with the human papillomavirus (HPV), no validated molecular profile of the disease has been established. By analyzing data from DNA microarrays, a study has confirmed the presence of four molecular classes of the disease. Also, previous results have been extended by suggesting an underlying connection between the molecular classes and observed genomic events, some of which affect cancer genes. This study also demonstrated the clinical relevance of the classes and certain genomic events, paving the way for further studies and possible targeted therapies.
"Cancer is a disease caused by alteration in the DNA and RNA molecules of tumors. A cancer results when broken molecules initiate a cascade of abnormal signals that ultimately results in abnormal growth and spread of tissues that should be under tight control within the body,” said Neil Hayes, MD, MPH, of the University of North Carolina Lineberger Comprehensive Cancer Center and of The Cancer Genome Atlas.
"However, most common tumors, including head and neck cancer, have relatively little information in the public record as to how these signals coordinate to create different patterns of abnormalities. This study is among the largest ever published to document reproducible molecular tumor subtypes. Subtypes, such as those we describe, represent attractive models to understand and attack cancers for treatment and prognosis."
The team analyzed a set of nearly 140 HNSCC samples. By searching for recurrent patterns known as gene expression signatures, they detected four gene expression subtypes. These subtypes are termed basal, mesenchymal, atypical, and classical, based on similarities to established gene expression subtypes in other tumor types and expression patterns of specific genes. For potential clinical use, these subtypes are complementary to classification by HPV status and the putative high-risk marker CCND1 copy number gain.
In spite of being the seventh most common form of cancer in the United States, HNSCC is relatively understudied in comparison to other tumor types (eg, breast and lung). By leveraging the similarities found in the gene expression subtypes, the results of this study provide a connection to a range of well-established findings and additional insight into the disease.
This study was published in PLOS ONE (2013; doi:10.1371/journal.pone.0056823).