Background. Altered glycosylation is a common phenotype expressed in essentially all types of human cancer and has been found to be correlated closely with the invasive and metastatic properties of a given tumor. Because there was no prognostic information concerning aberrant glycosylation of seminoma, the authors studied this topic.
Methods. Glycosphingolipid (GSI.) composition of or- chiectomy samples of seminoma were analyzed systematically. GSL patterns from seminoma samples of the fol- lowing three groups were compared after a 44-month postoperative period: Stage I disease with no evidence of metastasis during the 44-month postoperative period, Stage I with metastatic relapse during this period, and Stage I1 with retroperitoneal lymph node metastasis. Unknown GSLs detected were analyzed chemically by 'H- nuclear magnetic resonance spectroscopy and mass spectrometry.
Results. All nonmetastatic seminomas (n = 12) contained a GSL band that was identified as galactosylgloboside (Gb,; GalBl -+ 3GalNAcBl + 3Galal -4 GalBl 4 4Glcj31 + 1Cer). All metastatic seminomas (n = 5) lacked this GSL, although the sample sizes were admittedly small.
Conclusion. Only the presence or absence of galactosylgloboside (Gb,), but of no other GSL or gangliosides, clearly correlated with metastatic potential in patients with seminoma. This observation is useful in the estimation of prognosis of patients with seminoma, especially those with Stage I disease.