[A Case Report of Gastric Cancer Excised after Neoadjuvant Chemotherapy and Long-Term Survival Achieved after NivolumabAdministration for Peritoneal Dissemination].

The patient was a 64-year-old man with Type 3 advanced cancer in the upper body of the stomach. The preoperative tumor marker value of CA19-9 was abnormally high, but there was no proof of distant metastasis or peritoneal dissemination. The first operation was an exploratory laparotomy due to direct tumor invasion to the pancreas. Systemic chemotherapy was performed for tumor reduction. First, S-1 plus cisplatin therapy was administered for 4 courses but discontinued because of renal dysfunction and thrombocytopenia. In the second-line therapy, ramucirumabplus paclitaxel therapy was administered for 7 courses. Since the tumor invasion to the pancreas turned to be clear based on a CT scan, total gastrectomy with regional lymphadenectomy was performed. However, 5 months after surgery, a single nodule appeared in the upper abdomen that was suspected to be peritoneal dissemination. Nivolumab therapy was administered for 16 months without tumor enlargement or any adverse effect. Recently, there has been a marked development in chemotherapy for gastric cancer. Unresectable cases became operable after the administration of appropriate chemotherapy. In our case, nivolumab therapy had no adverse effect. However, serious adverse effects have been reported by several authors which suggests that regular examinations for interstitial pneumonia, hypothyroidism, and other adverse effects are important.

[A Case of Long-Term Survival of a Postoperative Recurrence of Duodenal Papilla Adenosquamous Carcinoma Associated with the Annular Pancreas].

A woman in her mid-50's presented to our hospital with jaundice, fatigue, and fever. Jaundice, elevated tumor markers, and lower bile duct stricture suggested malignancy, for which subtotal stomach-preserving pancreaticoduodenectomy was performed. The patient also had annular pancreas as the second part of the duodenum was surrounded by pancreatic parenchyma. The histopathological diagnosis was adenosquamous carcinoma of the duodenal papilla associated with annular pancreas. Adjuvant chemotherapy with TS-1 was administered for 1 year. Although para-aortic lymph node metastasis was detected radiographically 3 years 9 months after surgery, the recurrence remains under control and she is alive at 5 years 9 months after surgery due to multidisciplinary therapy.

[A Case of Advanced Gastric Cancer with Right Gastroepiploic Vein Tumor Thrombus Treated by Preoperative S-1 plus CDDP That Resulted in Pathological Complete Response].

We report a case of advanced gastric cancer with right gastroepiploic vein tumor thrombus treated using preoperative S-1 plus cisplatin(CDDP)in which pathological complete response was achieved. A 78-year-old man was diagnosed with type 2 gastric cancer located at the greater curvature of the antrum, accompanied by right gastroepiploic vein tumor thrombus. Four courses of S-1 plus CDDP were administered as neoadjuvant chemotherapy. After 2 courses, computed tomography(CT) revealed the disappearance of the tumor in the right gastroepiploic vein thrombus. Distal gastrectomy with D2 lymphadenec- tomy was performed, and the diagnosis was pathological complete response(CR). Eight courses of S-1(100mg/day on days 1-28, followed by 2 weeks of rest)were administered as adjuvant chemotherapy. During the 1-year postoperative follow up, the patient showed no recurrence. An S-1 plus CDDP regimen can be a useful preoperative chemotherapy option for advanced gastric cancer with tumor vein thrombus.