title: Is MAGE-1 expression in metastatic malignant melanomas really helpful?
abstract: Melanoma antigen-encoding gene (MAGE-1) has been introduced as a sensitive immunohistochemical marker to aid in the diagnosis of malignant melanomas, in particular, those that are HMB-45 negative. Our goal was to determine the consistency of positive staining in melanomas on the basis of the usefulness of MAGE-1 in comparison with tyrosinase and MART-1. We studied 56 malignant melanomas using immunohistochemical markers to MAGE-1, tyrosinase, MART-1, HMB-45, and S-100. Six of 17 HMB-45-negative cases were strongly positive for MAGE-1 (35%), while 9 of 39 HMB-45-positive cases were positive for MAGE-1 (23%), overall, 27% positivity (n = 56). Tyrosinase and MART-1 were both strongly positive in 42 of 56 cases (75%). Fifty-two of 56 cases were strongly positive for S-100 (93%). We found MAGE-1 to be less sensitive than described in other studies, and overall, not very helpful, especially as a predictor of aggressive behavior. Although MAGE-1 expression has been considered as a target for immunomodulation therapy, our findings do not indicate consistent expression of this epitope in a majority of melanomas. S-100 protein, tyrosinase, and MART-1 immunomarkers were more frequently positive in our melanoma cases and appear to constitute a useful panel of markers to aid in the diagnosis of metastatic malignant melanomas, especially in patients with an unknown primary.
authors.affiliation: Department of Pathology, David Geffen School of Medicine at the University of California at Los Angeles, Los Angeles, CA 90095, USA. ngajjar@mednet.ucla.edu
authors.forename: Nupoor A
authors.initials: NA
authors.lastname: Gajjar
authors.forename: Alistair J
authors.initials: AJ
authors.lastname: Cochran
authors.forename: Scott W
authors.initials: SW
authors.lastname: Binder
mesh_terms: D000276:Adjuvants, Immunologic / Q000627:therapeutic use; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor / Q000032:analysis*; D005260:Female; D006098:Granulocytes; D006801:Humans; D007150:Immunohistochemistry; D007519:Isoantigens / Q000032:analysis; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000188:drug therapy / Q000235:genetics; D058950:Melanoma-Specific Antigens; D008875:Middle Aged; D014442:Monophenol Monooxygenase / Q000032:analysis; D009363:Neoplasm Proteins / Q000032:analysis / Q000235:genetics*; D009418:S100 Proteins / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D000276:Adjuvants, Immunologic; D000951:Antigens, Neoplasm; D014408:Biomarkers, Tumor; C531098:HNA-4A antigen; D007519:Isoantigens; C072011:MAGEA1 protein, human; D058950:Melanoma-Specific Antigens; D009363:Neoplasm Proteins; D009418:S100 Proteins; D014442:Monophenol Monooxygenase