An ideal diagnostic test for cancer would be noninvasive and provide
accurate results with sufficient specificity and sensitivity.
Currently, no test for cancer meets all of these criteria. However,
results of a study presented at the annual meeting of the American
Association for Cancer Research (AACR) raise hope that a noninvasive,
accurate way to detect certain types of cancer with a simple saliva
test may soon be available.
Markers Specific to Squamous Cell Carcinoma
David Sidransky, md, professor and director of the Head and Neck
Cancer Research Division, Andre L. Reed, MD, and Michael F. Spafford,
MD, head and neck oncology fellow and instructor, respectively, at
Johns Hopkins University School of Medicine, and colleagues have
developed a test that uses saliva to detect squamous cell cancer of
the head and neck.
Using molecular analysis, the investigators compared the saliva of 21
patients undergoing surgery for head and neck squamous cell carcinoma
with cells from the actual tumors. They found certain markers in
saliva specific to the tumor type in 71% of the cancer patients. By
contrast, saliva from 27 tumor-free controls--smokers and nonsmokers
without tumors--failed to show any of the specific markers.
"While a positive result seems to be specific to squamous cell
carcinoma of the head and neck, the test is not yet able to detect
all patients with this type of cancer," said Dr. Spafford.
"We are currently working on improving the detection rate of the
test, optimizing the collection method, and analyzing the saliva of
tumor patients following treatment. Early detection would allow us to
treat these patients less invasively, thus sparing them from the
potentially disfiguring and disabling effects of surgery."