Patients with oropharyngeal cancer caused by the human papilloma virus (HPV) should be double tested to improve their outcomes, according to new research. One test detects the actual virus, the other looks for the P16 protein that has been established as a commonly used biomarker for HPV, and which is easier and cheaper to test for.
The results of this international trial were published in The Lancet Oncology. The study was coordinated by Hisham Mehanna at the University of Birmingham in U.K., and lead author of the paper.
Mehanna said, “We have been able to answer a question that has perplexed the head and neck cancer community for over two decades. In that time there has been an emergence of a new type of head and neck cancer this cancer called Human papillomavirus (HPV) related head and neck cancer, caused by the same virus that is often responsible for cervical cancer.”
The incidence of oropharyngeal cancer has increased rapidly worldwide over the last twenty years, mainly because of the increase in HPV-related disease. Because of the high cost and implementation difficulties of HPV DNA and RNA testing, overexpression of the protein p16 on immunohistochemistry is widely used as a surrogate for determining HPV related disease. However, a large proportion of patients have discordant tests—they are p16-positive patients who are HPV negative or p16-negative patients that are HPV positive.
This team looked at studies from 13 head and neck cancer centers from nine countries around the world. It comprised data of 7,895 patients. Results showed that in a significant number of patients results are discordant.
They found that five-year overall survival rates were:
- 81% among those with double positive tests,
- 53% for patients with p16-/HPV+ test
- 54% for patients with p16+/HPV- tests for patients
“What is remarkable is that patients with HPV head and neck cancer respond much better to current therapies than patients [whose cancers] are not HPV related,” Mehanna said. As a result, we are trying to look for less toxic treatments for these patients to reduce the burden of toxicity. For patients who are HPV negative, we are doing clinical trials to increase the intensity of treatment—to try to improve outcomes.”
He added that, “Therefore, testing for HPV in head and neck cancer patients has become a real priority and this new research has solved the conundrum puzzling the international community about why some patients respond much better to treatment than others.”
Patients with discordant tests who smoke were at much higher risk of worse outcomes, as the study found that their cancer acted like HPV negative cancers. On the other hand, patients with discordant tests who did not smoke had tumors that had good outcomes, like HPV positive cancers.
Mehanna said, “This has significant implications on how we test head and neck cancer patients moving forward, especially in regions where smoking is still prevalent and HPV disease is not prevalent. For example, southern Europe and countries in the east. It also has significant implications for how we choose which studies to enroll these patients in, and in future what treatment they get.”
