RESUMO
PURPOSE: Analyze the significance of serum S100 as tumor marker and study it in the sentinel node biopsy and in the whole body FDG-PET studies. MATERIAL AND METHODS: 332 melanoma patients diagnosed of cutaneous melanoma were included (41 untreated and 291 previously treated). Serum levels were measured by an immunoradiometric assay. Cut-off value was 0.2 microg/l. RESULTS: In the 41 untreated patients, the S100 mean values were: mean 0.36 microg/l, median 0.29 microg/l, with 56.1% of positivities. Serum mean values in stage III and IV were significantly higher than stage I and II (0.489 microg/l vs 0.209 microg/l) (p < 0.05). The mean serum value of S100 in treated patients and without evidence of disease was 0.14 microg/l and the median 0.13 microg/l. Sensitivity and specificity for detection of recurrence or metastases in the follow-up were 76.2% and 88.6%, respectively. There is a correlation of 91.3% between S100 and FDG-PET studies (23 patients). S100 does not provide information on the sentinel lymph node biopsy. CONCLUSIONS: S100 is not useful to diagnose melanoma in its early stages but it is a good tumor marker for the follow-up and monitoring of melanoma patients.
