Background/Objectives:Commonly characterized by limited metastatic sites, low tumor burden has been associated with favorable patient outcomes in various malignancies. However, its prognostic relevance in avelumab maintenance therapy for advanced urothelial carcinoma (UC) remains incompletely defined.Methods:We retrospectively analyzed 26 patients with advanced UC who received avelumab maintenance therapy following disease control with first-line platinum-based chemotherapy between March 2021 and May 2025. Patients were categorized by their metastatic pattern at a chemotherapy initiation: lymph node-only (as a surrogate for low tumor burden), non-visceral (excluding visceral organ involvement, but including bone), or visceral disease. Survival outcomes were assessed using the Kaplan–Meier method.Results:Among the cohort, 46.2% had lymph node-only metastasis and 57.7% had non-visceral disease. The median progression-free survival (PFS) and overall survival (OS) from the start of avelumab were 5.6 months and 21.7 months, respectively. OS from the initiation of platinum-based chemotherapy was 28.7 months. Patients with lymph node-only metastasis demonstrated significantly longer OS from chemotherapy initiation compared with those with other metastatic patterns (41.1 vs. 22.9 months,p= 0.044). However, the PFS and OS from avelumab initiation did not significantly differ. No survival benefit was observed for patients with non-visceral disease compared with those with visceral metastases.Conclusions:Lymph node-only metastasis, representing low tumor burden, was associated with significantly improved long-term survival in advanced UC patients undergoing avelumab maintenance following chemotherapy. These findings support the clinical utility of baseline tumor burden and metastatic pattern in risk stratification and shared decision-making for maintenance therapy in advanced UC.
背景/目的：低肿瘤负荷通常以转移部位有限为特征，与多种恶性肿瘤患者良好预后相关。然而，其在晚期尿路上皮癌（UC）阿维鲁单抗维持治疗中的预后意义仍未完全明确。 方法：我们回顾性分析了2021年3月至2025年5月期间，26例在一线铂类化疗获得疾病控制后接受阿维鲁单抗维持治疗的晚期UC患者。根据化疗起始时的转移模式将患者分为三类：仅淋巴结转移（作为低肿瘤负荷的替代指标）、非内脏转移（排除内脏器官受累，但包括骨转移）或内脏转移。采用Kaplan-Meier法评估生存结局。 结果：队列中46.2%患者为仅淋巴结转移，57.7%为非内脏转移。自阿维鲁单抗治疗开始的中位无进展生存期（PFS）和总生存期（OS）分别为5.6个月和21.7个月。自铂类化疗开始的总生存期为28.7个月。与其他转移模式患者相比，仅淋巴结转移患者自化疗起始的总生存期显著延长（41.1个月 vs. 22.9个月，p=0.044）。然而，自阿维鲁单抗起始的PFS和OS无显著差异。与非内脏转移患者相比，内脏转移患者未观察到生存获益。 结论：在化疗后接受阿维鲁单抗维持治疗的晚期UC患者中，代表低肿瘤负荷的仅淋巴结转移与长期生存显著改善相关。这些发现支持基线肿瘤负荷和转移模式在晚期UC维持治疗风险分层和共同决策中的临床应用价值。
Avelumab Maintenance Therapy for Advanced Urothelial Carcinoma with Low Tumor Burden
肿瘤(癌症)患者之家