A blood test can detect antibodies of HPV that can cause throat and oral cancers years before the symptoms of the disease become apparent, researchers from the National Cancer Institute and the International Agency for Research on Cancer reported in the Journal of Clinical Oncology.
In the study, close to 1 in 3 people with oropharyngeal cancer had antibodies to HPV (human papilloma virus), compared with fewer than 1 in 100 without cancer. When present, these antibodies could be found several years before onset of the disease.
These results show that a blood test could one day be used to find patients with this type of cancer.
In the past, most oropharyngeal cancers were thought to be caused by tobacco use and alcohol consumption rather than HPV infection. However, prevalence of this malignancy is rising in several areas of the world, especially in Europe and the U.S., because of elevated infection with HPV type 16.
In the U.S. approximately 60% of current cases of oral cancers are due to HPV 16. Continuous infection with HPV 16 results in cellular changes that cause cancer.
Additionally, HPV E6 is one of the viral genes that aids in tumor formation. Earlier research of patients with HPV-related oropharynx cancer found antibodies to E6 in their blood.
Aimee R. Kreimer, Ph.D., the lead Investigator from the Division of Cancer Epidemiology and Genetics, NCI said:
“Our study shows not only that the E6 antibodies are present prior to diagnosis””but that in many cases, the antibodies are there more than a decade before the cancer was clinically detectable, an important feature of a successful screening biomarker.”
Kreimer and her team tested samples from subjects in the European Prospective Investigation into Cancer and Nutrition Study, a long-term study of over 500,000 healthy adults in 10 European countries.
The investigators examined blood from 135 people who developed oropharyngeal cancer between one and 13 years later, as well as 1,600 subjects who did not develop cancer.
They found antibodies against the HPV16 E6 protein in 35% of people with cancer, compared with less than 1% of the samples from the people who were cancer-free.
Blood samples were taken six years before diagnosis, but the relationship was independent of the time between diagnosis and blood collection. Antibodies to HPV16 E6 protein were also found in blood samples gathered over 10 years before diagnosis.
The researchers documented that HPV16 E6 antibodies could be a biomarker for better survival, which is in line with previous reports.
Subjects in the study with oropharyngeal cancer who tested positive for HPV16 E6 antibodies prior to diagnosis were 70% more likely to be alive after follow-up, compared to those with the same cancer who tested negative.
Paul Brennan, Ph.D., the lead investigator from IARC, concluded:
“Although promising, these findings should be considered preliminary. If the predictive capability of the HPV16 E6 antibody holds up in other studies, we may want to consider developing a screening tool based on this result.”
Celebrity Michael Douglas recently announced that his stage 4 throat cancer was not caused by alcohol use and smoking, but rather oral sex.
Written by Kelly Fitzgerald