Background: Immunotherapy has transformed cancer treatment; however, predicting treatment response remains challenging. Serum biomarkers can help identify patients who are most likely to benefit from immunotherapy. Objective: This study evaluates the relationship between serum growth differentiation factor 15 (GDF-15) and interleukin-6 (IL-6) levels and treatment outcomes in cancer patients undergoing second-line immunotherapy. Methods: We conducted a prospective observational study involving 85 patients with non-small-cell lung cancer (NSCLC), renal cell carcinoma (RCC), or malignant melanoma treated with nivolumab. The baseline serum levels of GDF-15 and IL-6 were measured by using ELISA kits. The primary endpoints were progression-free survival (PFS) and overall survival (OS), with cachexia as a secondary outcome. Results: Elevated GDF-15 levels were significantly associated with shorter PFS (HR: 0.55, 95% CI: 0.32–0.96,p= 0.032) and OS (HR: 0.47, 95% CI: 0.25–0.90,p= 0.020). Higher IL-6 levels correlated with shorter PFS, though statistical significance was not achieved. Additionally, high GDF-15 levels were linked to increased cachexia incidence (p= 0.037). Conclusion: Our findings indicate that GDF-15 could serve as a prognostic biomarker for immunotherapy response and may also be a target for cachexia management. Further studies should explore its potential to guide clinical decision making in oncology.
背景：免疫疗法已革新癌症治疗，但预测治疗反应仍具挑战。血清生物标志物有助于识别最可能从免疫治疗中获益的患者。目的：本研究评估接受二线免疫治疗的癌症患者血清生长分化因子15（GDF-15）与白细胞介素-6（IL-6）水平与治疗结局的关系。方法：我们对85例接受纳武利尤单抗治疗的非小细胞肺癌、肾细胞癌或恶性黑色素瘤患者开展前瞻性观察研究，采用ELISA试剂盒检测基线血清GDF-15和IL-6水平。主要终点为无进展生存期（PFS）和总生存期（OS），恶病质作为次要结局指标。结果：GDF-15水平升高与较短的PFS（HR：0.55，95% CI：0.32–0.96，p=0.032）和OS（HR：0.47，95% CI：0.25–0.90，p=0.020）显著相关。IL-6水平升高与PFS缩短存在关联，但未达到统计学显著性。此外，高GDF-15水平与恶病质发生率增加相关（p=0.037）。结论：本研究表明GDF-15可作为免疫治疗反应的预后生物标志物，并可能成为恶病质管理的干预靶点。后续研究应进一步探索其在肿瘤临床决策中的指导潜力。
Impact of Serum GDF-15 and IL-6 on Immunotherapy Response in Cancer: A Prospective Study
肿瘤(癌症)患者之家