Baseline staging of melanoma with unknown primary site: the value of serum s100 protein and positron emission tomography.
BACKGROUND
Baseline staging is important in all melanoma types, including melanoma with unknown primary site (MUP). Staging includes different examination strategies, each with different accuracy.


OBJECTIVE
To determine the value of serum S100 protein levels and positron emission tomography (PET) in the baseline staging of MUP.


METHODS
Twenty patients with MUP were evaluable for the analysis between 1996 and 2007 with both S100 assessment and PET performed for baseline staging.


RESULTS
Serum S100 was elevated in 7 patients (35%). The PET scan detected the metastases in 6 of 7 patients with elevated serum S100 protein showing a strong correlation (p = 0.005). Patients with metastases had significantly higher serum S100 levels (p = 0.01) than the ones without. Serum S100 protein was shown to be discriminative between patients with and without metastases (receiver-operating characteristic, p = 0.012) with 75% sensitivity and 92% specificity.


CONCLUSIONS
Serum S100 protein appears to be a sensitive as well as specific marker to detect metastases. We therefore might recommend serum S100 assessment to be included in the baseline staging of MUP.
Oberholzer
Patrick A
PA
Department of Dermatology, University Hospital Zurich, Zurich, Switzerland. patrick.oberholzer@usz.ch
Urosevic
Mirjana
M
Steinert
Hans C
HC
Dummer
Reinhard
R
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D008545:Melanoma / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000556:secondary; D008875:Middle Aged; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D009418:S100 Proteins / Q000097:blood*; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000556:secondary
D014408:Biomarkers, Tumor; D019275:Radiopharmaceuticals; D009418:S100 Proteins