Comparative study on the clinical use of protein S-100B and MIA (melanoma inhibitory activity) in melanoma patients.
BACKGROUND
The guidelines for the care of melanoma patients have not recommended the routine use of tumor markers up till now. In comparison to the blood parameters, two serum proteins have demonstrated their usefulness in the follow-up of melanoma patients: protein S-100B, a member of the S100 protein family, and "Melanoma-inhibitory activity" (MIA), a recently described 11 kd soluble protein. We analysed the serum levels of S-100B and MIA in non-melanoma control patients and in melanoma patients in different stages of disease (stage I-IV) to report on the sensitivity and specificity of both tumor markers.


METHODS
The serum concentration of S-100B was evaluated by a luminoimmunometric assay (LIA) in 670 blood samples of 87 melanoma patients and, as controls, in 169 blood samples of patients with different skin diseases apart from melanoma. MIA serum levels were measured by an enzyme-linked immunoassay (ELISA) in 791 serial blood samples of 87 melanoma patients and in 158 blood samples of control patients. A cut-off of 0.12 microgram/l (S-100B) and 6.5 micrograms/l (MIA) served as upper normal values in the melanoma group as recommended by the producing industrial companies. In the control patient group, we additionally used the cut-off value of 0.2 microgram/l for S-100B and 8.5 micrograms/l for MIA, respectively.


RESULTS
In stage I/II 37.5%, in stage III 50% and in stage IV 80% of the blood samples were S-100B positive (> or = 0.12 microgram/l) prior to treatment. Post treatment (after complete surgery) S-100B was below the cut-off value in stage I/II 83.9%, in stage III 82% and in stage IV 85.7%, respectively. For MIA we found in stage I/II 0%, stage III 53.8% and in stage IV 68.3% of the blood samples positive (> or = 6.5 micrograms/l) prior to treatment. Post treatment: stage I/II 88.3%, stage III 90.3% and stage IV 93.1% were below the cut-off value. In the control group we found 85.8% and 89.9% of the blood samples beneath the cut-off values for S-100B and MIA, respectively.


CONCLUSIONS
We were able to identify the majority of patients with advanced metastatic melanoma by analysing the serum levels of S-100B and MIA. The specificity of both tumor markers was within acceptable limits. However, the available data suggest that a slightly higher cut-off value might be of clinical value.
Schmitz
C
C
Department of Dermatology at the University of Kiel, Schittenhelmstr. 7, D-24105 Kiel, Germany. cs1971@hotmail.com
Brenner
W
W
Henze
E
E
Christophers
E
E
Hauschild
A
A
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D008545:Melanoma / Q000097:blood / Q000175:diagnosis*; D009414:Nerve Growth Factors; D011379:Prognosis; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000097:blood*; D012680:Sensitivity and Specificity
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C074879:MIA antigen, human; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins