"We found that S100A4 mRNA was present at significantly higher levels in the group of cancer patients, no matter whether they had colorectal or gastric cancer, than in the tumor-free control group," Stein said in a statement. "And there were yet higher levels in the patients with metastases than in those where the disease had not yet metastasized."
In addition, patients who developed metastases later had higher S100A4 levels in their initial blood tests than those whose disease did not metastasize, Stein said. "This means that in future we might be able to identify those patients who are likely to develop metastases," she said.
These findings need to be replicated in larger populations, but the test could eventually be used to screen the general population to detect these cancers early, the researchers say.
"We are hoping that, by enabling the identification of those patients whose disease is likely to progress more quickly, we will be able to treat them in the future accordingly by tailoring therapy to their individual needs," Stein said.
Marchetti agreed. "Hopefully, with this screening you will detect a lot more stage I and II cancers than we do now which are likely to become aggressive," he said.
"This study shows, regardless of the stage, if you find an increased level of this gene in patients, even with early cancer, now you will have a reason to treat these patients with chemotherapy and radiation, and potentially cure more patients," Marchetti said.
Colorectal cancer strikes one in 17 people in their lifetime, according to background information provided in the study. Colonoscopy is highly sensitive but invasive, while fecal occult blood tests, which require patients to return stool samples to their doctor, are distasteful to some people. Since blood tests are already part of most physical examinations, a colon cancer blood test might improve screening rates, the researchers said.
For more information on colon cancer, visit the American Cancer Society.
SOURCES: Joost Louwagie, M.D., OncoMethylome Sciences, Liege, Belgium; Floriano Marchetti, M.D., assistant professor of surgery, director of the Colon and Rectal Surgery Residency Program, University of Miami Sylvester Comprehensive Cancer Center; Sept. 21, 2009, presentations, 15th Congress of the European Cancer Organization and 34th Congress of the European Society for Medical Oncology, Berlin