According to an international research team finding, antibodies against the human papillomavirus (HPV) 16 can be detected up to 40 years before the diagnosis of a head and neck tumor. People with HPV16 antibodies also have a much higher risk of oropharyngeal tumors.
According to the researchers’ observations in the USA, the detection of specific antibodies against HPV16 increases the risk of developing a head and neck tumor in the caucasian population by a factor of 100, whereas the risk of developing a head and neck tumor in the black population increased by a factor of 17.
The prospects indicate that oropharyngeal tumors associated with positive HPV findings react significantly better to cancer therapy than those without virus involvement. The observed difference between people with caucasian or black ancestry may explain why black patients in the USA often showed a worse outcome.
The main causes of oropharyngeal tumors continue to be smoking and alcohol abuse. However, HPV16 infection has recently been detected in up to 70% of cancer cases in US and European studies, which is why HPV infection is now considered to be another reliable risk factor for the development of head and neck tumors.
However, there is still no certain method for reliably detecting head and neck tumors, such as throat cancer, before the first symptoms appear. Thus, there are currently no known precancerous conditions or markers in these cases that would allow a risk assessment and early detection as part of a screening. According to the researchers, HPV16 antibodies could be helpful in closing the diagnostic gap in the future.
Until present, decades can pass between the detection of antibodies and the possible development of cancer, and even at a higher risk, not every patient with positive detection will develop a tumor. As a result, HPV antibody screening would very probably lead to a large number of false-positive findings.
As a reason for explaining the observed increase in HPV-associated head and neck tumors, the scientists stated that since around the mid 20th century not only oral sex practices had become very established, but also a decrease in tonsillectomy rates had been observed, which quite simply gave the viruses more infectious tissue.
The vaccination available today against nine different HPV subtypes, including HPV16, can almost 100% prevent viral infection. However, the success of the vaccination with regard to head and neck tumors will probably only become apparent in a few decades due to the long period of tumor development, the researchers concluded.
Kreimer AR et al., Timing of HPV16-E6 antibody seroconversion before OPSCC: findings from the HPVC3 consortium. Annals of Oncology 2019: doi:10.1093/annonc/mdz0138