The challenge of developing useful blood-based biomarkers in melanoma

Usefulness of neuron-specific enolase as a serum marker of metastatic melanoma

Treatment strategies for advanced melanoma are dramatically changing, due to immune-checkpoint inhibitors and BRAF/MEK inhibitors. Nevertheless, reliable serum markers for evaluation of treatment responses and the outcome are still limited. Some previous reports suggested that serum neuron-specific enolase (sNSE) may be a useful marker for melanoma; however, its usefulness is controversial. Moreover, NSE has not been examined in vitro by using melanoma cell lines. We retrospectively evaluated sNSE and serum lactate dehydrogenase (sLDH) levels at the initial diagnosis and during therapy in 33 melanoma patients of various stages. We analyzed the NSE concentrations in cell lysates and supernatants from melanoma cell lines by enzyme-linked immunosorbent assay. The median sNSE was significantly higher in stage IV patients compared with stages I/II and III (16.3, 12.7 and 12.1 ng/mL, respectively). sNSE was elevated in 20% (2/10) of stage III and 61.1% (11/18) of stage IV patients but not in stages I/II. sNSE and sLDH tended to correspond to the total tumor volume (P = 0.48 and 0.58; 95% confidence intervals, 0.005-0172 and 0.776-0.836, respectively). The coincidence rate of sNSE and sLDH in stage IV at the initial diagnosis was 11 of 18 (61.1%). Of the remaining patients, elevated sNSE but not sLDH was observed in five patients (27.8%) and elevated sLDH but not sNSE was observed in two (11.1%). Four of the five patients showing elevated sNSE and normal sLDH were of the mucosal type. NSE was detected in both supernatant and cell lysate of all four melanoma cell lines (0.30-237.32 ng/mL and 137-483.04 ng/mg, respectively). Two cell lines with a high supernatant NSE level contained many dead cells in the supernatant. The combination of sNSE and sLDH could contribute to the early detection of distant metastasis and disease condition evaluations for advanced melanoma patients.

Established and Emerging Biomarkers in Cutaneous Malignant Melanoma

In an era of personalized medicine, disease specific biomarkers play an increasing role in the stratification of high-risk patient groups. Cutaneous malignant melanoma is the most deadly form of skin cancer with an ever-increasing global incidence, especially in patients under 35-years of age. Despite the excellent prognosis for patients diagnosed with early stage disease, metastatic disease still carries significant overall mortality. Biomarkers aim not only to identify high-risk patients, but also to provide potential therapeutic targets for differing patient subgroups. Furthermore, accessibility to tissue samples from a range of disease stages in malignant melanoma, unlike most other solid tissue tumours, provides the unique opportunity to explore the biology of tumour progression that may be relevant in the biology of cancer as a whole. Over the past decade, there have been major advances in targeted therapies, providing new avenues and hope to patients with this devastating disease. This review will focus on most up to date histological, serological and molecular biomarkers in malignant melanoma.