Correlation between lipid-associated sialic acid and tumor burden in melanoma.

Recent studies have suggested that lipid-associated sialic acid (LSA) may be a useful tumor marker for monitoring patients with melanoma, but the relationship between LSA and tumor burden has not been previously studied. We therefore examined LSA levels in 240 patients of whom 169 had no clinical evidence of disease (NED) and 71 had metastatic disease. There was a statistically significant difference in LSA levels in patients with NED compared with metastatic disease as well as those with high tumor burden compared with low or intermediate tumor burden. There was no difference between the groups with low and intermediate tumor burden. An LSA level of 25 mg/dl provided a positive predictive value of 70% and a negative value of approximately 80%. Our data show that LSA levels correlate with tumor burden in patients with melanoma.