Blood Test Detects Sexually Transmitted Throat Cancer

A blood test can detect antibodies of human papilloma virus (HPV) that can cause throat and oral cancers years before the symptoms of the disease become apparent.

Antibodies against the HPV oncogenes E6 and E7, other viral regulatory proteins, E1, E2, and E4, and the L1 antigen for multiple HPV types have been investigated in prediagnostic plasma from patients with head and neck cancer (HNC).

An international team led by scientists at the US National Cancer Institute (Bethesda, MD, USA) and the International Agency for Research on Cancer (Lyon, France) identified 638 participants with incident head and neck cancers patients. Of these 180 were oral cancers, 135 were oropharynx cancers, 247 were hypopharynx/larynx cancers, and 300 patients with esophageal cancers as well as 1,599 comparable controls.

Prediagnostic plasma samples from patients were collected, on average, six years before diagnosis and control participants were analyzed for antibodies against multiple proteins of HPV16 as well as HPV6, HPV11, HPV18, HPV31, HPV33, HPV45, and HPV52. Plasma samples were tested at the German Cancer Research Center (DKFZ; Heidelberg, Germany) where multiplex assays were performed using antigens that were affinity-purified, bacterially expressed fusion proteins with N-terminal Glutathione S-transferase.

Seropositivity to HPV16 E6 was present in prediagnostic samples for 34.8% of patients with oropharyngeal cancer and 0.6% of controls, but was not associated with other cancer sites. The increased risk of oropharyngeal cancer among HPV16 E6 seropositive participants was independent of time between blood collection and diagnosis and was observed more than 10 years before diagnosis.

The authors concluded that 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.

Aimee R. Kreimer, PhD, the lead investigator 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." The study was published on June 17, 2013, in the Journal of Clinical Oncology.

Related Links:
US National Cancer Institute
International Agency for Research on Cancer
German Cancer Research Center