Value of serum S-100B for prediction of distant relapse and survival in stage III B/C melanoma.

BACKGROUND: The biochemical marker serum S-100B has been proven to reflect the stage of melanoma and to be useful for disease monitoring and prediction of survival, mainly in stage IV disease. For stage III melanoma, limited data are available and its predictive value for relapse is unknown. Serum S-100B was evaluated prospectively for monitoring response and its predictive value for relapse and overall survival in stage IIIB/C melanoma patients. PATIENTS AND METHODS: Treatment consisted of one cycle of neoadjuvant and adjuvant chemo(immuno)therapy, around surgery. S-100B was measured at enrollment and prior to and following surgery. The levels of S-100B in serum were compared to the pattern and intensity of the expression of S-100B in the melanoma tissue. RESULTS: Some patients with normal initial S-100B values (n=18) showed responses (3 complete remission and 2 partial remission), in contrast to patients with elevated S-100B values. Distant relapse within one year was found in 11/23 (48%) patients with increased S-100B versus 2/18 (11%) patients with a normal value (p=0.01). Overall survival was decreased in patients with increased S-100B compared to those with normal S-100B (p=0.02). Correlations between the pattern and intensity of S-100B expression in the tumor specimen and the value of serum the S-100B did not reach statistical significance. CONCLUSION: Serum S-100B is a valuable biomarker for the evaluation of response to treatment and prediction of early distant relapse and survival in stage IIIB/C melanoma. The marginal correlation between serum S-100B values and expression of S-100B in the tumor specimens needs further study.

Comparison of four different assays for determination of serum S-100B.

BACKGROUND: S-100B determination has been shown to be clinically useful in the management of melanoma patients. After the development of a test for determination of the isoforms S100-A1B and S100-BB in serum (S-100B), several sensitive assays for the detection of serum S-100B have become available. We compared four S-100B assays, two automated (LIAISON Sangtec 100 and Elecsys S100) and two manual ones (Sangtec 100 ELISA and CanAg S100 EIA), with respect to clinical data, reference values and correlation. METHODS: In a total of 280 samples from 155 melanoma patients and 98 healthy individuals S-100B values were measured simultaneously with the different assays. RESULTS: The inter and intra coefficients of variation were best for the automated assays. The functional sensitivity of both manual assays was 0.15 microg/L. Method comparison revealed satisfactory correlation coefficients of 0.9 or higher, but the slopes ranged from 0.29 to 3.36. Except for the Sangtec 100 ELISA, the linearity between the assays was acceptable. The overall sensitivity for melanoma ranged from 37% (Elecsys S100) to 47% (LIAISON Sangtec 100) and the sensitivity increased with stage. ROC curves showed the best accuracy for the LIAISON Sangtec 100 assay. CONCLUSIONS: All assays gave satisfactory results, but it is advisable to improve the performance of the manual assays for better sensitivity. Agreement about an international reference standard is needed.

Nocardia farcinica as the causative agent in a primary psoas abscess in a previously healthy cattle inspector.

A 42-year-old, previously healthy cattle inspector presented with a 7-day history of fever, a painful left knee, malaise and muscular pain. He did not suffer from an underlying disease, nor was he immunocompromised. After 12 days of hospitalization, a unilocular abscess in the left psoas muscle was diagnosed. Nocardia farcinica was isolated from the aspirate. No connection with his work could be demonstrated. The patient was successfully treated with trimethoprim-sulfamethoxazole for 11 months.