Staging and follow-up of patients with melanoma: which tests for which patients?

Monthly changes in serum levels of S100B protein as a predictor of metastasis development in high-risk melanoma patients

BACKGROUND

The role of S100B protein in detecting early melanoma relapses is controversial, since most metastasis occur within normal values of S100B.

OBJECTIVE

The aim of this study was to assess the performance of S100B in detecting early disease progression in high-risk melanoma patients.

METHODS

Retrospective cohort study including patients with an initial diagnosis of stage IIB, IIC and III melanoma between January 2003 and July 2013. All patients were followed up in accordance with an intensive protocol based on imaging studies and serum S100B levels every 3-6 months. We compared two methods to evaluate changes in S100B. The classic method referring to a single determination of S100B above the cut-off level at the time of metastasis, which was evaluated in all patients. And a new method based on monthly changes of S100, which was used in the setting of patients with S100B levels within the normal range.

RESULTS

Overall, 289 of patients were followed up for 44 months (IQR 17-73) and 45% developed metastases. During the study period, 129 patients relapsed of which 46 (35.7%) present elevated values of S100B at the time of relapse. The classic method had a sensitivity and specificity of S100B protein of 35.7% and 92.5%, respectively. Furthermore, for the patients that relapsed with normal values of S100B, the new method was applied and showed a sensitivity and specificity of 41.1% and 92.4%, respectively, allowing to detect additional relapses that were missing by the classic method.

CONCLUSION

During follow-up of high-risk melanoma patients, rising serum S100B values within the normal range can be an important clue to disease progression.

Genetic polymorphisms may influence the vertical growth rate of melanoma

Background: Identification of new predictive markers in melanoma is of great clinical importance. This study was aimed to analyze association between selected common variants in the cancer susceptibility genes and melanoma progression at the time of diagnosis. Material and Method: The study included 243 consecutive patients with melanoma. Genotyping was performed using real-time PCR. Results: Our data revealed modest association between xeroderma pigmentosum complementation group D (XPD) codon 312 polymorphism and tumor thickness (as defined by Breslow score; XPD D312N CC: 3.00 ± 3.78mm, CT: 1.71 ± 2.48mm, TT: 2,53 ± 3,24mm, P=0.023). The CT genotype in XPD D312N polymorphism was more frequently represented in non-invasive melanomas compared to deeply penetrating tumors. None of the common SNPs in cyclin dependent kinase inhibitor 2A (CDKN2A), vitamin D receptor (VDR), melanocortin 1 receptor (MC1R) were associated with Breslow depth. Conclusion: These findings suggest that genetic alteration in XPD contributes to melanoma progression and may be a potential diagnostic and molecular prognostic marker.