Expression of the blood protein osteopontin may be an independent prognostic marker for melanoma, clinicians report in the journal Cancer.
Dr Mohammed Kashani-Sabet from the University of California, San Francisco and associates analysed osteopontin expression in relation to outcome in 345 patients with melanoma.
They found that higher expression of the protein was associated with increasing tumour thickness, and other factors associated with a poor outcome.
The risk of relapse increased from 32 percent in melanoma patients with no osteopontin expression to 51 percent in patients with some osteopontin expression, the investigators found, and increased osteopontin expression was associated with significantly reduced survival free of relapse.
Ups death risk
Similarly, the risk of death from melanoma increased from 22 percent in patients with low osteopontin expression to 33 percent in patients with high osteopontin expression.
Osteopontin expression also predicted spread of the cancer to the lymph nodes and higher osteopontin expression was associated with higher average numbers of positive lymph nodes.
The risk of lymph node metastasis increased from 8.8 percent among patients with no osteopontin expression to 32.9 percent among patients with osteopontin expression.
"The application of molecular genomics to melanoma is already here," Kashani-Sabet told Reuters Health. "Molecular markers such as osteopontin may help address some of the difficult clinical scenarios that we face today." - (Will Boggs, MD/Reuters Health)
SOURCE: Cancer, January 1, 2008.