Lymph node metastasis is a key stage of malignant tumor progression and a core factor affecting the efficacy of immunotherapy. The therapeutic response of lymph node metastases to immune checkpoint inhibitors (ICIs) varies significantly among different cancer types, and the underlying regulatory mechanisms remain unclear. This single-center, retrospective observational study was approved by the Ethics Committee of Sun Yat-sen Memorial Hospital of Sun Yat-sen University (Approval No.: SYSKY-2026-278-01). We plan to enroll no less than 5000 patients with pan-cancer lymph node metastasis who received ICI therapy in our hospital. The efficacy of primary tumors (T) and metastatic lymph nodes (N) before and after immunotherapy will be evaluated based on TNM staging changes, and the objective response rate (ORR) at both levels will be calculated. Patients will be divided into two groups according to the use of β-blockers during immunotherapy to compare the ORR differences, and explore the clinical factors affecting the efficacy of immunotherapy for pan-cancer lymph node metastases. This study aims to provide evidence-based medical basis for formulating individualized immunotherapy strategies for pan-cancer lymph node metastasis.