Highlights
- In HPV-associated cancer of the oropharynx, the immune system responds by producing antibodies against a human papillomavirus type 16 (HPV16) protein E6.
- These antibodies against HPV16 E6 are regarded as very valuable biomarkers of oropharyngeal cancer and can be detected in the blood samples of patients, long before the clinical symptoms manifest.
- A single blood sample taken at any point of time might be sufficient for assessing a person's risk for developing cancer of the oropharynx for many years.
The DKFZ researchers collaborated in this project with colleagues from the International Agency for Research on Cancer (IARC) and the U.S. National Cancer Institute.
The immune system responds to an infection with HPV by producing antibodies against components of the virus. The chronically infected cells produce a HPV protein E6 (HPV16 E6) that plays an important role in the development of cancer.
Antibodies produced against HPV16 E6 are regarded as very valuable indicators of oropharyngeal cancer.
Test
Around 198 blood samples from patients with tumors of the oropharynx were studied. The samples had been taken when the participants entered the study, long before the onset of the disease. The control samples comprised 924 participants without cancer diagnosis.
"This pretty much corresponds to the percentage of HPV-related cases of oropharyngeal cancer that we expected to find for that time in the American population," Tim Waterboer said.
The findings also revealed that if the test result for HPV16 E6 antibodies is positive once, it remains stable over many years.
"This means that a single blood sample test taken at any point of time might be sufficient for assessing a person's risk for developing cancer of the oropharynx within the next 10 years," said Waterboer.
The detection of HPV16-E6 antibodies is at present, not a suitable method for early cancer detection in larger population groups.
"The occurrence of new cases of oropharyngeal cancer is rather low at about five cases per 100 000 inhabitants," said Waterboer, who is the study head. "That means that although the test is highly specific, very many healthy people would receive false positive results. However, in certain high-risk groups, up to ten times more people can develop the disease. HPV16 E6 antibody detection is the first ever easy-to-analyze biomarker that enables us to narrow down the circle of individuals who are at an extremely high risk of developing the cancer."
The test for antibodies against HPV16 E6 is not suitable for assessing the risk for HPV-associated cervical cancer, and other cancers in genital areas. This is because the revealing antibodies do not occur in the genital areas before the cancer becomes clinically detectable.
The findings are reported in the Journal of the National Cancer Institute.
Reference
- Tim Waterboer et al. Kinetics of the Human Papillomavirus Type 16 E6 Antibody Response Prior to Oropharyngeal Cancer. Journal of the National Cancer Institute; (2017) DOI: https://doi.org/10.1093/jnci/djx005
Source-Medindia