Long-Term Complete Response to Trastuzumab Deruxtecan in a Case of Unresectable Gastric Cancer.

Introduction: Trastuzumab deruxtecan (T-Dxd) has been approved for the treatment of HER2-positive gastric cancer. However, there are only a limited number of cases of gastric cancer where a long-term complete response (CR) has been maintained. Consequently, we report a case of gastric cancer in which long-term CR was maintained. Case Presentation: A woman in her late 60s underwent a gastrointestinal endoscopy, which revealed a type 2 lesion with ulceration in the lesser curvature of the vestibule, and a biopsy, which revealed an adenocarcinoma. Computed tomography (CT) revealed wall thickening of the gastric antecubital region, metastatic liver tumor, and extra-regional lymph node metastasis; a diagnosis of T4a, N3a, M1 (H, LYN), and cStage IVB (HER2 3+) was confirmed. Trastuzumab, oxaliplatin, and S-1 were administered initially. After 9 months, ascites appeared, and progressive disease was diagnosed. Paclitaxel and ramucirumab were started as second-line treatments but discontinued owing to neutropenia and increasing ascites. Third-line treatment with T-Dxd was initiated, and 11 months later, CT showed the disappearance of metastases. Even after 31 months, the CR was maintained. Conclusion: To the best of our knowledge, this is one of the few cases in which long-term CR was maintained with third-line T-Dxd treatment. Treatment strategies for patients with gastric cancer to achieve long-term CR require careful consideration.

[A case report of primary duodenal adenocarcinoma responding to chemotherapy with S-1 and irinotecan].

A 5 3-year-old woman was admitted to our hospital because of vomiting. CT scan and gastroduodenoscopy showed severe stenosis of the duodenal 3rd portion. There was no evidence of malignancy. We diagnosed a stricture due to a duodenal ulcer and laparotomy was performed. By means of biopsy of No.14d lymph node in the operation, adenocarcinoma of the duodenum was pointed out and we performed a pancreatoduodenectomy. Although adjuvant chemotherapy with S-1/paclitaxel (S-1 80 mg/body, po, day 1-14 and paclitaxel 120 mg/body iv day 1, 8)was administered after operation, the patient's serum CEA was elevated and metastic lymph nodes around the supra mesenteric artery were pointed out. The patient was started on combined chemotherapy with S-1/CPT-11(S-1 80 mg/body, po, day 1-14 and CPT-11 120 mg/body iv day 1), serum CEA levels returned to normal range, and marked reduction of lymph node size was observed on CT. The patient is still alive and free of disease three years after the operation. S-1/CPT-11 could therefore be a treatment option for patients with duodenal carcinoma.

Double intussusceptions in the small intestine caused by metastatic renal cell carcinoma: report of a case.

Renal cell carcinoma (RCC) may metastasize to almost any organ, but it is unlikely to be a direct cause of intussusception. We report a case of double enteric intussusceptions caused by metastatic RCC in a 64-year-old man. The patient presented with intermittent abdominal pain and diarrhea 11 years after undergoing a radical nephrectomy. Abdominal computed tomography (CT) showed two enhanced masses with the "target" sign, suggesting enteric intussusceptions. We performed partial enterectomy, and histological examination confirmed that the tumors had originated from RCC. To our knowledge, this is the first report of metastases from RCC manifesting as synchronous intraluminal polypoid tumors serving as the lead points of two intussusceptions in the small intestine. Thus, the possibility of multiple tumor metastases in the small intestine, with or without intussusceptions, should be considered in patients with recurrent RCC.