NEW YORK (Reuters Health) – An elevated plasma osteopontin level is significantly associated with gastric cancer development and poor survival, Taiwanese researchers report in the June issue of the journal Gut.
Osteopontin levels have been linked to a number of malignancies, note Dr. Jaw-Town Lin and colleagues at National Taiwan University Hospital in Taipei, and they investigated whether or not there was a link with gastric cancer.
Using reverse polymerase chain reaction and immunohistological staining, the researchers measured plasma osteopontin expression in 11 gastric cancer specimens.
"Expression of osteopontin mRNA was significantly higher in gastric cancer tissues compared with nontumour tissues," Dr. Lin’s team reports.
The team also analyzed plasma osteopontin levels in 132 patients with gastric cancer and 93 healthy controls, and found the median level was significantly higher in patients than controls.
"Osteopontin is not only a marker, but also an upstream molecule of the osteopontin-uPA-MMPs signal transduction pathway, which plays an essential role in gastric cancer invasion," Dr. Lin told Reuters Health. "In in vitro studies, osteopontin induces gastric cancer cell invasion."
Furthermore, high osteopontin levels were significantly associated with advanced stages, lymph node involvement, and liver metastasis.
Specifically, at a cutoff value 67.3 ng/mL, plasma osteopontin has a sensitivity of 58.3% and a specificity of 69.9% for detection of gastric cancer, Dr. Lin said. For detection of gastric cancer lymph node metastasis, osteopontin has a sensitivity of 65.1% and a specificity of 65.3% at a cutoff value of 73.0 ng/mL, and for gastric cancer liver metastasis, it has a sensitivity of 87.5% and a specificity of 83.1% at a cutoff value of 111.2 ng/mL.
"We are conducting research in community populations and in patients with precancerous lesions (atrophic gastritis and intestinal metaplasia) and other high risk populations to test the diagnostic value of osteopontin in the different development stages of gastric cancer," Dr. Lin added.
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