Patients with oligometastatic squamous cell carcinoma were enrolled and randomly assigned to receive either PD-1 inhibitor +/- chemotherapy combined with local therapy or PD-1 inhibitor +/- chemotherapy alone.

The primary end point was progression-free survival (PFS). The secondary end points included overall survival, side effects and local control.

Patients with oligometastatic squamous cell carcinoma were enrolled and 2:1 randomly assigned to receive either PD-1 inhibitor +/- chemotherapy combined with local therapy (radiotherapy, surgery, radiofrequency/microwave ablation, etc.) or PD-1 inhibitor +/- chemotherapy alone. Different local therapy techniques are allowed to be used on different lesions in the same patient.All suspected malignant lesion should be included in local treatment planning in principle.

The primary end point was progression-free survival (PFS). The second end points included overall survival, side effects and local control.

Inclusion Criteria:

• 1. ≥18 years old; 2. ECOG 0-1; 3. Esophageal squamous cell carcinoma 4. ASTRO/ESTRO defined genuine oligometastatic disease and consistent with: i. ≤4 distant metastases, ii. ≤3 metastatic lesions within a single organ, iii. maximum diameter of each metastatic lesion ≤5cm; 5. ≥1 pathologically diagnosed metastases

Exclusion Criteria:

• 1. History of disseminated metastases or ASTRO/ESTRO defined induced oligometastatic disease 2.Esophageal perforation/hemorrhage 3.Progression disease after PD-1 inhibitor treatment 4.In-field recurrence 5.Intolerance to chemotherapy or immunotherapy 6.lung V20>25%