[A Case of Esophagogastric Junction Cancer Treated Successfully with Conversion Surgery after Complete Response to Nivolumab Treatment].

As shown in the ATTRACTION-2 trial, nivolumab is effective as third-line chemotherapy for advanced or recurrent gastric cancer and esophagogastric junction cancer. We report a patient with esophagogastric junction cancer who underwent conversion surgery after third-line chemotherapy with nivolumab. The patient was a 72-year-old woman. Upper gastrointestinal endoscopy revealed advanced esophagogastric junction cancer of Siewert type Ⅱ, and computed tomography revealed multiple hepatic and pulmonary metastases. The esophagogastric junction cancer was diagnosed as cT3N1M1, cStage Ⅳb, and she was administered SP as first-line and nab-PTX/RAM as second-line treatment, but progressive disease remained. Nivolumab as a third-line treatment remarkably reduced the hepatic and pulmonary metastases after its administration was initiated, and conversion surgery was performed after 28 courses. The pathological diagnosis was ypT1b2(SM2), ypN0. After discharge from the hospital, postoperative chemotherapy with nivolumab was continued in the outpatient clinic, and there has been no evidence of disease progression.