Thomas Brigham is a 48-year-old electrician. He is married with three beautiful children. During his free time, he loves to go hunting with his hometown friends. Thomas is a social drinker but has never smoked tobacco. So, it came as a surprise to him when he noticed a lump in his neck last year and was diagnosed with tonsillar cancer.
In the past, the typical candidate for this kind of cancer were older patients with a heavy smoking or drinking history. But in the past decades, doctors have been seeing an influx of younger men with head and neck cancers, often non-smokers and otherwise in good health — until they noticed that lump in their throat.
The cause? Human papillomavirus, or HPV.
Here are some surprising facts:
- There has been a 300 percent increase in oropharyngeal cancer among men during the past 40 years.
- Approximately one in nine men, ages 18 to 69, are infected with oral HPV. That’s 11 million men, compared to 3 million women.
- Approximately 70 percent of all oropharynx cancers in the United States are caused by HPV.
- Not all HPV carries a cancer risk, but the strain that does, oral HPV 16, was six times more common in men than women in the study.
- The overall prognosis of HPV-related head and neck cancer is much better than the traditional causes of head and neck cancer.
Studies have shown that less than 50 percent of patients with the traditional head and neck cancer were still alive after five years, compared to more than 70 percent with HPV-associated head and neck cancer, with an equivalent stage and disease burden.
That is a significant improvement in survival. Why is the prognosis so different? The answer might be within how a virus replicates.
How does a virus cause cancer? Viruses can’t make copies of themselves. Instead, they hijack the reproductive machinery of cells to do the job.
Eventually, the cell will die, leaving the virus without a way to reproduce. One way to get around that is to “rewire” the cell to live and reproduce forever. The unlimited reproductive ability is how a cancer cell is created.
Tumors caused by HPV express different proteins on their surfaces, and doctors can test those cells when they take biopsies to see if the tumor is related to the virus.
Because of these proteins, it’s possible for our immune system to recognize these tumor cells easier than typical cancer cells. Thus, our immune system might be assisting us in the elimination of these cancers with treatment, allowing for a better prognosis.
Also, carcinogens like cigarette smoke and alcohol often cause traditional head and neck cancers. Those exact a lot more DNA damage than the viruses do. Therefore, treatment might not be as effective on damaged tissue.
There are many more theories, but regardless of the reasons, we know that HPV-related head and neck cancers respond better to treatment. In fact, studies have shown that we can potentially give patients less intense (de-intensified) regimens of chemotherapy and radiation, reduce side effects and maintain the same tumor control and survival.
Thus, systematic clinical investigations are ongoing that should enable us to more accurately identify patients who can safely be treated with treatment de-intensification without compromising overall prognosis.
Vaccination efforts are ongoing in teenagers and young adults, but the impact of such programs likely will not be realized for another 20 to 30 years.
Routine screening from dentists and primary care physicians for head and neck cancer also will become increasingly important, as we will see younger patients develop head and neck cancer.