Authors: Elena Conroy, Future Science Group
A study by researchers at the University of California San Diego, School of Medicine (CA, USA) has found evidence suggesting that the high mortality rates in head and neck squamous cell carcinoma (HNSCC) may be linked to genetic deletions on the cancer genome’s third chromosome. This study, which was published recently online in Nature Genetics, suggests that mutations of the TP53 tumor suppressor gene in HNSCC coincide with a 3p deletion. The link between the two markers had not been previously observed and may be a promising finding for the identification and subsequent treatment of HNSCC.
The study involved analyzing the complete genomic signatures of 250 samples of squamous cell head and neck cancer, the data for which was extracted from The Cancer Genome Atlas. Results from the analysis demonstrated that half of the patients who had both mutations would likely die of cancer within 2 years, while 66% of the patients with one or neither mutations had a life expectancy of 5 years or longer.
The results indicate that there may be important therapeutic value in testing for both the TP53 mutation and the 3p deletion in these patients. If both markers are present, treatment could be intensified potentially increasing life expectancy of patients suffering from HNSCC. Additionally, if only one of the mutations were present, treatment could be de-intensified potentially leading to a reduction in deaths caused by complications during medical care.
As well as mutations in tumor suppressor genes, the human papilloma virus (HPV) is also known to cause head and neck cancers. Another exciting finding from this study was that HPV is able to influence the activity of TP53 and have the same effects as a TP53 mutation on cells. Furthermore, the most aggressive HPV-positive tumors were also found to be linked to 3p deletions.
“We are in the early stages of being able to personalize head and neck cancer treatments based on the tumor’s actual biology, the same as what’s done with breast cancers,” commented co-senior author Quyen Nguyen, associate professor of Otolaryngology-Head and Neck Surgery at University of California, San Diego School of Medicine. “In the past, treatments have been based largely on the size and location of the tumor. Now, we know that some large tumors may respond to less aggressive treatment while some small tumors may need intensified treatment. This will have a huge impact for patients.”
Sources: Gross Am, Orosco RK, Shen JP, et al. Multi-tiered genomic analysis of head and neck cancer ties TP53 mutation to 3p loss. Nat Gen. DOI: 10.1038/ng.3051 (2014) [Epub ahead of print]; University of California San Diego press release