This study aims to investigate the safety and efficacy of radiotherapy combined with Toripalimab (PD-1 inhibitor) in the treatment of locally advanced adenocarcinoma of the gastroesophageal junction.

In this study, patients with locally advanced adenocarcinoma of gastroesophageal junction will be enrolled to explore the safety and efficacy of preoperative radiotherapy and chemotherapy combined with Toripalimab (PD-1). Around 45 patients will be recruited in this one-arm cohort. All patients in this cohort will be treated with preoperative radiotherapy and chemotherapy plus PD-1 for two times, then another two times of PD-1 before operation. After surgery, postoperative chemotherapy plus PD-1 will be carried out for four times. This study focuses on the safety of chemoradiotherapy combined with immunotherapy, and whether the TRG grade, LC, DFS have been improved.

Inclusion Criteria:

• 1) Age 18-75, male and female.

  2) ECOG score was 0-1.

  3) Diagnosis of adenocarcinoma in the gastroesophageal junction.

  4) Initial treatment of locally advanced patients (cT3-4 or N+, and M0).

  5) The estimated survival time will be more than 12 months.

  6) Adequate organ reserve function.

  7) agree to join the group, willing to cooperate with clinical research, and sign the informed consent.

Exclusion Criteria:

• 1) Patients have received immunotherapy, such as PD-1 antibody, PD-L1 antibody and CTLA4 antibody.

  2) Immunosuppressive drugs were used within 4 weeks before admission.

  3) Active infection, acute myocardial infarction in recent 6 months, severe arrhythmia requiring long-term drug intervention, severe stroke, uncontrolled epilepsy or other serious medical complications.

  4) In the past five years, there have been other malignant diseases except for cured skin cancer and cervical cancer in situ.