Head and neck squamous cell carcinoma (HNSCC) is the fifth most common cancer worldwide, with approximately 5,000 patients diagnosed annually in Canada. Both disease and treatment can have a profound negative impact on the patient’s quality of life due to disfigurement, difficulty speaking and swallowing.
Approximately 25 per cent of head and neck cancers are caused by oral infection with the human papillomavirus (HPV). These tumours are typically found in younger, non-smoking patients, and are highly responsive to treatment. Most HPV-negative tumours are caused by smoking, but one-third of these patients have no smoking history.
In the first genomic analysis of head and neck cancer by smoking status, researchers at Lawson, in collaboration with researchers at the Ontario Institute for Cancer Research and UCLA Cancer Centre, carried out a comprehensive genetic analysis of HPV-negative tumours to better understand the link between smoking and cancer recovery.
Two genes, NSD1 and COL1A11, were more frequently mutated in heavy smokers. “We were surprised to find that patients carrying the NSD1 mutation experienced significantly better outcomes compared to those carrying the wild-type gene. Smoking is definitely bad and causes head and neck, and numerous other cancers, however a subset of these smoking related cancers that carry NSD1 tend to be significantly less aggressive,” says Dr. Anthony Nichols, Lawson Scientist, physician and Chair of the Head and Neck Disease Site Team at London Health Sciences Centre (LHSC).
Finding genetic mutations in tumours of heavy smokers is common, due to the high amount of exposure to the various carcinogens found in cigarette smoke. What is remarkable about this particular mutation is its association with improved outcomes.
Targeted gene sequencing of NSD1 was later conducted in 77 oral cavity cancer tumours from patients treated at LHSC. Improved overall survival was observed for patients with NSD1 mutations, supporting what the researchers found through data analysis.
Dr. Nichols explains that for patients who have a relatively good prognosis, there is great interest in using a less intense cancer treatment protocol.
“The NSD1 mutation could be used as a clinical biomarker for less intense treatment protocols, ultimately benefiting the patient by improving their quality of life with fewer side effects.”
The study, “Mutational analysis of head and neck squamous cell carcinoma stratified by smoking status” was recently published in JCI Insight.