Blood and Saliva Tests Help Predict Recurrence of HPV-Related Oral Cancer
Physicians at Johns Hopkins have developed blood and saliva tests that help accurately predict recurrences of HPV-linked oral cancers in a substantial number of patients. The tests screen for DNA fragments of the human papillomavirus (HPV) shed from cancer cells lingering in the mouth or other parts of the body. A description of the development by Ahn et al was published recently in JAMA Otolaryngology – Head & Neck Surgery.
“There is a window of opportunity in the year after initial therapy to take an aggressive approach to spotting recurrences and intensively addressing them while they are still highly treatable,” said Joseph Califano, MD, Professor of Otolaryngology - Head and Neck Surgery, member of the Johns Hopkins Kimmel Cancer Center, and Medical Director of the Milton J. Dance, Jr. Head and Neck Center at the Greater Baltimore Medical Center. “Until now, there has been no reliable biological way to identify which patients are at higher risk for recurrence, so these tests should greatly help do so,” he added.
Patients with HPV-associated oropharyngeal cancers are generally examined every 1 to 3 months in the first year after diagnosis. Recurrences are often found when patients report ulcers, pain, or lumps in the neck. But imaging tests are unreliable in detecting cancer recurrence earlier, and the location of oropharyngeal cancers—in the tonsils, throat, and base of the tongue—make it difficult for physicians to spot budding lesions.
Dr. Califano said survival rates for patients with early-stage, HPV-related oral cancers are as high as 90% within the first 2 years, and a study reported by Johns Hopkins experts in February showed that, even after recurrence, more than 50% of patients survive 2 years after their recurrence. The new blood and saliva tests have the potential to improve these rates, he added.
Study Details
For the study, the Johns Hopkins team analyzed blood and saliva samples from 93 patietns with oropharyngeal who were treated with surgery, radiation alone, or combined chemotherapy and radiation at The Johns Hopkins Hospital or Greater Baltimore Medical Center. Samples were collected before and after treatment. Of these patients, 81 had HPV-positive tumors. The researchers selected patients with a variety of early-to-advanced stage cancers, and none of the patients had distant metastasis.
The blood and saliva tests were performed using polymerase chain reaction, which amplifies certain portions of DNA and measures its amount. The scientists found that HPV DNA detected in patients’ saliva after treatment was predictive for recurrence nearly 20% of the time in a subset of the patients. When the scientists looked for HPV DNA in the blood of another subset of patients, the accuracy of a recurrence prediction rose to more than 55%. In a third subset of patients, finding HPV DNA in both blood and saliva samples after treatment accurately predicted recurrence 70% of the time.
Despite the encouraging results, Dr. Califano said that further refinements are still badly needed to improve detection of possible recurrences because HPV is highly prevalent in our bodies. “We can’t be sure our test results are cancer-specific and not due to other forms of HPV infection or exposure,” he said.
His team is looking for other genomic biomarkers that would increase the specificity of HPV DNA testing in blood and saliva. Dr. Califano also cautioned that the current study was too small to link test results to the severity of recurrence.
Funding for this study was provided by the National Institutes of Health’s National Cancer Institute/National Institute of Dental and Craniofacial Research.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
