A pinprick of blood may be enough to detect head, neck, and anal cancers linked to the HPV16 strain of the humanpapilloma virus (HPV) and predict their courses, according to a six-center European clinical study.
There are more than 200 types of HPVs. HPV16 is responsible for more than 90% of all HPV-related head and neck tumors and for more than 70% of all cases of cervical cancer. The new point-of-care biomarker test detects levels of the DRH1 antibody specific to HPV16, demonstrating a specific link between rising levels of these antibodies and cancer.
“This is the first time that we have been able to show a link between raised levels of this specific antibody and HPV cancers, indicating the course of the disease. This might raise the potential of being able to detect disease recurrence much earlier than current clinical practice,” said study leader Dr. Thomas Weiland of the Medical University of Graz in Austria.
The presence of HPV infection does not mean the patient has cancer. In most cases, the body clears the infection. The new test detects an antibody that is only produced when an infection has led to increased cell growth. Previously, the researchers said, no test had been able to discriminate an HPV infection from actual HPV-induced malignancy.
The study demonstrated a sensitivity of 90% to 95% for anal and oropharyngeal cancers and a specificity of 99.3%. These performance characteristics are diagnostically significant compared to existing methods for the early detection of HPV-induced cancers, the researchers said.
The researchers believe it is a promising biomarker test not only for the early diagnosis of HPV-related cancers but also for monitoring a patient’s response to therapy and as an early warning that the disease has returned.
“While HPV infection does not indicate cancer, scientists have suspected for some time that if antibodies were to develop, there may be a link to cancer. Being able to detect that early enough could have a major impact on patient outcomes,” said Dr. Ralf Hilfrich, founder of Abviris and creator of the DRH1 blood-based HPV tumor marker.
“The test’s specificity has enabled scientists to show that rising levels of HPV antibodies in blood do reflect malignancy. The study also indicates that it may provide diagnostically significant, compared to current detection methods, when a biopsy is hard to access, or where the site of the primary cancer is unknown or unidentifiable, such as very early metastasis,” said Hilfrich.
“We compared 1,500 patient samples, including carcinomas of the head and neck, oral cavity carcinomas, anal carcinomas, with those of the healthy control group,” said Weiland.
The overall study was divided into two parts. The retrospective study of patients with anal cancer was able to show that high antibody levels indicating anal cancer would have been detected more than six months (293 days) before the tumor had actually been picked up. The second part, a prospective study of head and neck cancer patients, monitored patients for two years after treatment, confirming the test’s ability to predict cancer.
Even with the success of the Pap smear and the vaccine, the researchers said, HPV-induced cancers remain a global health burden, with an estimated 7 billion unprotected people at risk and about 400,000 deaths annually.