|Blood Test for Head and Neck Cancers|
By Nancy Touchette
Posted: February 20, 2004
Scientists have taken a key first step towards developing a simple blood test to detect head and neck cancers in the early stages. Although the results are preliminary, no other screening tests are available for this class of cancers.
Head and neck cancers, which include tumors of the esophagus, throat, tongue, and mouth, account for five to seven percent of all cancers in the United States and an even higher percentage throughout the world.
“These tumors are often hidden and not seen until they are quite large,” says J. Trad Wadsworth of the Eastern Virginia Medical School in Norfolk, who led the recent study. “They are frequently misdiagnosed as viral illnesses. It’s only when the symptoms don’t go away that cancer is eventually detected, but often this doesn’t happen until the cancer has progressed.”
The new test being developed by Wadsworth and his colleagues relies on a technology called proteomics, which detects patterns of proteins in the blood. As tumors grow, different proteins appear in the bloodstream that can be detected before the actual tumor is evident.
In the study, the researchers first used blood samples from known cancer patients and healthy people to train computers to distinguish the normal protein patterns from the protein pattern associated with cancers.
Using that information, the researchers then tried to identify correctly blood samples from cancer patients, healthy smokers, and healthy nonsmokers. (Smoking is the greatest risk factor for theses cancers, which are often not detected until it is too late and the cancer has spread, or metastasized.)
The test correctly identified all healthy nonsmokers. It detected 83 percent of all head and neck cancer patients and 80 percent of healthy smokers.
“These results are encouraging, but it is still too early to be used in the clinic,” says Wadsworth. “We need to sample thousands rather than hundreds of patients and fine-tune the system to detect more of the cancers.”
Wadsworth is collaborating with researchers at other institutions to examine more blood samples. He says that initially the test may be more valuable for testing a population of patients, such as smokers, who have a greater risk for developing head and neck cancers than the general population.