PURPOSE With the recent developments in novel molecular targeted therapy such as immune-checkpoint blockades, serine/threonine-protein kinase B-Raf, and mitogen-activated protein kinase kinase inhibitors, the prognosis of advanced malignant melanoma has been improving. 5-S-cysteinyl-dopa (5-S-CD), a precursor of pheomelanin, has been previously revealed to be a useful biomarker for advanced-stage malignant melanoma, especially in patients with distant metastases. Here, we aimed to assess and compare the utility of serum 5-S-CD and lactate dehydrogenase levels as markers for predicting the effects of nivolumab in advanced malignant melanoma. METHODS Baseline serum 5-S-CD and lactate dehydrogenase levels in patients with unresectable stage IIIC and IV malignant melanoma treated with nivolumab (n = 21) were analyzed to determine their utility as predictive markers for survival. We also analyzed the prognostic value of these markers among patients with only stage IV malignant melanoma (n = 17). RESULTS Our analysis showed that patients with baseline serum 5-S-CD levels >25.0 nmol/L had significantly poor prognosis. In contrast, serum lactate dehydrogenase levels at the upper limit of the normal range did not exhibit such changes. CONCLUSIONS Serum 5-S-CD levels have the potential to be an excellent predictive marker for the efficacy of nivolumab therapy in patients with advanced malignant melanoma.

中文翻译：

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血清 5-S-半胱氨酰多巴水平作为 nivolumab 治疗晚期恶性黑色素瘤疗效的预测标志物。

目的随着免疫检查点阻断、丝氨酸/苏氨酸蛋白激酶B-Raf和丝裂原活化蛋白激酶激酶抑制剂等新型分子靶向治疗的最新进展，晚期恶性黑色素瘤的预后一直在改善。5-S-半胱氨酰多巴 (5-S-CD) 是褐黑素的前体，之前已发现它是晚期恶性黑色素瘤的有用生物标志物，特别是在有远处转移的患者中。在这里，我们旨在评估和比较血清 5-S-CD 和乳酸脱氢酶水平作为预测 nivolumab 在晚期恶性黑色素瘤中作用的标志物的效用。方法对接受纳武利尤单抗治疗的不可切除的 IIIC 和 IV 期恶性黑色素瘤患者（n = 21）的基线血清 5-S-CD 和乳酸脱氢酶水平进行分析，以确定它们作为生存预测标志物的效用。我们还分析了这些标志物在仅 IV 期恶性黑色素瘤 (n = 17) 患者中的预后价值。结果我们的分析显示，基线血清5-S-CD水平>25.0 nmol/L的患者预后明显较差。相比之下，正常范围上限的血清乳酸脱氢酶水平没有表现出这种变化。结论 血清 5-S-CD 水平有可能成为晚期恶性黑色素瘤患者 nivolumab 治疗疗效的极好预测标志物。我们还分析了这些标志物在仅 IV 期恶性黑色素瘤 (n = 17) 患者中的预后价值。结果我们的分析显示，基线血清5-S-CD水平>25.0 nmol/L的患者预后明显较差。相比之下，正常范围上限的血清乳酸脱氢酶水平没有表现出这种变化。结论 血清 5-S-CD 水平有可能成为晚期恶性黑色素瘤患者 nivolumab 治疗疗效的极好预测标志物。我们还分析了这些标志物在仅 IV 期恶性黑色素瘤 (n = 17) 患者中的预后价值。结果我们的分析显示，基线血清5-S-CD水平>25.0 nmol/L的患者预后明显较差。相比之下，正常范围上限的血清乳酸脱氢酶水平没有表现出这种变化。结论 血清 5-S-CD 水平有可能成为晚期恶性黑色素瘤患者 nivolumab 治疗疗效的极好预测标志物。