Uniform assessment of response to treatment is crucial to managing multiple myeloma (MM) and developing new therapies. Measurement of monoclonal protein forms the cornerstone of disease assessment in MM. According to International Myeloma Working Group (IMWG) guidelines, serum-free light chain (sFLC) is included in MM response assessment in patients with no measurable disease by electrophoresis and to define stringent complete response. We retrospectively analyzed the independent value of serial FLC on response and progression assessments in 839 patients with measurable disease by sFLC as well as serum/urine electrophoresis. A significant association was observed between sFLC and electrophoretic responses during initial therapy and at best response (p < 0.001). This study revealed comparable percentage changes in serial dFLC and urine M-protein, with parallel trends (p < 0.001) and strong correlations (r 0.55–0.79, p < 0.001). The response was detected earlier by sFLC (1.1 months, 95% CI 1.06–1.17), and sFLC ≥ PR after two cycles of induction demonstrated a strong predictive value for subsequent electrophoresis responses (OR 9.33, p < 0.001). Following induction, no difference in PFS was observed between very good partial response (VGPR) as determined by sFLC, sPEP, and uPEP (p = 0.538). The median second-PFS for patients with only sFLC-progression disease (PD) was similar to those with urine M-protein PD with or without sFLC-PD (HR 1.28, 95% CI 0.77–2.13, p 0.334). However, the median overall survival from the first relapse was significantly better for patients with only sFLC-PD (HR 1.87, 95% CI 1.07–3.27, p 0.03). Among patients with PD, 12% had sFLC as the only detectable tumor marker at the time of second-line therapy. This study supports the incorporation of serial sFLC measurements for monitoring response and progression in MM, even in patients with electrophoretic measurable disease, and further advocates replacing 24-h urine with serial sFLC in response assessment.
统一评估治疗反应对管理多发性骨髓瘤（MM）及开发新疗法至关重要。单克隆蛋白的检测是MM疾病评估的基石。根据国际骨髓瘤工作组（IMWG）指南，血清游离轻链（sFLC）被纳入无法通过电泳检测到可测量疾病患者的MM疗效评估，并用于定义严格完全缓解。我们回顾性分析了839例经sFLC及血清/尿电泳确认存在可测量疾病患者的系列FLC数据在疗效和疾病进展评估中的独立价值。结果显示，在初始治疗期间及最佳疗效时，sFLC与电泳反应之间存在显著关联（p < 0.001）。本研究发现系列dFLC与尿M蛋白的百分比变化具有可比性，呈现平行趋势（p < 0.001）且高度相关（r 0.55–0.79，p < 0.001）。sFLC可更早（提前1.1个月，95% CI 1.06–1.17）检测到治疗反应，且诱导治疗两周期后sFLC ≥ 部分缓解（PR）对后续电泳反应具有强烈预测价值（OR 9.33，p < 0.001）。诱导治疗后，通过sFLC、血清蛋白电泳（sPEP）和尿蛋白电泳（uPEP）判定的非常好的部分缓解（VGPR）患者在无进展生存期（PFS）上无显著差异（p = 0.538）。仅sFLC进展性疾病（PD）患者的中位第二次PFS与伴有或不伴sFLC-PD的尿M蛋白PD患者相似（HR 1.28，95% CI 0.77–2.13，p=0.334）。然而，仅sFLC-PD患者从首次复发起的中位总生存期显著更优（HR 1.87，95% CI 1.07–3.27，p=0.03）。在PD患者中，12%在二线治疗时仅sFLC可作为可检测的肿瘤标志物。本研究支持将系列sFLC检测纳入MM疗效及进展监测体系，即使对于电泳可测量疾病患者亦然，并进一步主张在疗效评估中以系列sFLC检测替代24小时尿蛋白检测。
肿瘤(癌症)患者之家