A long-surviving case of gastric cancer with main portal vein tumor thrombus after surgical resection and postoperative S-1 therapy.

Gastric cancer patients with main portal vein tumor thrombus usually have a short survival time, owing to its aggressive behavior. Herein, we report a long-surviving case of gastric cancer with main portal vein tumor thrombus. A 78-year-old man presenting with anorexia and body weight loss was diagnosed with gastric cancer. The patient was referred to our hospital for further examination and treatment. Endoscopy revealed a type 3 tumor (8.0 cm in length) in the body of the stomach. Biopsy led to the diagnosis of moderately differentiated adenocarcinoma. Enhanced computed tomography revealed a large tumor thrombus extending from the gastric coronary vein to the portal trunk. A total gastrectomy with lymphadenectomy, splenectomy, and thrombectomy was performed. Postoperative chemotherapy with S-1 was administered for 18 months. The patient died a natural death without recurrence at 49 postoperative months. To the best of our knowledge, the patient was the oldest to be diagnosed with gastric cancer with main portal vein tumor thrombus at diagnosis, who survived >36 months. Although gastric cancer with main portal vein tumor thrombus is a rare occurrence, its prognosis is extremely poor. Intensive surgery and long-term chemotherapy may be effective at improving survival time in these patients.