Oesophagobronchial perforations after placement of an oesophageal self-expanding metallic stent.

An oesophageal fully covered self-expanding metallic stent (SEMS) was placed in a 54-year-old Japanese man to relieve dysphagia owing to a stage cT1bN3M1c lung adenocarcinoma. High expression of programmed cell death-ligand 1 was microscopically confirmed, and pembrolizumab was subsequently administered. Several days later, the patient was hospitalized with septic shock, and severe mediastinitis and pneumonia caused by oesophageal SEMS-induced oesophageal and bronchial perforations were observed. Thoracoscopic surgery was performed to drain the mediastinal abscess, and an additional oesophageal SEMS was placed to close the oesophageal perforation. The patient gradually recovered from the potentially fatal infection, and the SEMS was retrieved after confirming perforation closure. We re-initiated pembrolizumab administration, and the patient responded well. The present report reveals the potential risk and effectiveness of SEMS, especially when administered with immune checkpoint inhibitors.

Increase in Carbohydrate Antigen 19-9 Levels without Tumor Progression after Polaprezinc Administration that Induced Deep Vein Thrombosis in a Colon Cancer Patient.

Carbohydrate antigen 19-9 (CA 19-9) is a well-known tumor marker of adenocarcinoma (reference range, 37 U/mL). It can also be used, together with computed tomography, to monitor responses and resistance to chemotherapy in cancer patients. False elevation of CA 19-9 levels is often seen in conditions such as biliary tract obstruction and cholangitis. However, whether medication might induce false elevation of CA 19-9 levels has not yet been reported. A 74-year-old man was treated with third-line CPT-11 (irinotecan) plus panitumumab for stage IV cancer of the ascending colon. The patient developed chemotherapy-induced dysgeusia and was treated with polaprezinc. After polaprezinc administration, his CA 19-9 levels gradually increased from 18.9 to 1,699.4 U/mL. He developed deep vein thrombosis (DVT), although it was not associated with progressive disease or metastasis. Upon discontinuation of polaprezinc, CA 19-9 levels gradually decreased. This case demonstrates that polaprezinc may not only induce false elevation of CA 19-9 levels but also cause development of DVT induced by increased CA 19-9 levels, both of which are very rare events.

[A case of unknown primary cancer responding to TS-1].

A 65-year-old male showed elevated tumor marker and intra-abdominal lymph node (LN) swelling. PET revealed an accumulation of FDG at para-aortic LNs from the mediastinum to the inguinal region. Although many different examinations were performed to detect primary cancer, none was found. We diagnosed unknown primary cancer (UPC), and administered TS-1 (100 mg/day). Six months later, the tumor marker lowered and the LN swelling reduced. PET showed a little accumulation of FDG at intra-abdominal LN. An intra-abdominal LN biopsy was performed, and an adenocarcinoma was seen at a lymph vessel. Then, 15 months later, brain metastasis was recognized and 18 months later the patient died of systematic metastasis. Autopsy was not performed, and primary cancer was not seen till the end. TS-1 proved effective for the UPC.

Adipocytes from Munc18c-null mice show increased sensitivity to insulin-stimulated GLUT4 externalization.

Insulin-stimulated glucose uptake in adipocytes is mediated by translocation of vesicles containing the glucose transporter GLUT4 from intracellular storage sites to the cell periphery and the subsequent fusion of these vesicles with the plasma membrane, resulting in the externalization of GLUT4. Fusion of the GLUT4-containing vesicles with the plasma membrane is mediated by a soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex consisting of vesicle-associated membrane protein 2 (VAMP2), 23-kDa synaptosomal-associated protein (SNAP23), and syntaxin4. We have now generated mouse embryos deficient in the syntaxin4 binding protein Munc18c and show that the insulin-induced appearance of GLUT4 at the cell surface is enhanced in adipocytes derived from these Munc18c-/- mice compared with that in Munc18c+/+ cells. Wortmannin, an inhibitor of PI3K, inhibited insulin-stimulated GLUT4 externalization, without affecting GLUT4 translocation to the cell periphery, in Munc18c+/+ adipocytes, but it did not affect GLUT4 externalization in Munc18c-/- cells. Phosphatidylinositol 3-phosphate, which induced GLUT4 translocation to the cell periphery without externalization in Munc18c+/+ cells, elicited GLUT4 externalization in Munc18c-/- cells. These findings demonstrate that Munc18c inhibits insulin-stimulated externalization of GLUT4 in a wortmannin-sensitive manner, and they suggest that disruption of the interaction between syntaxin4 and Munc18c in adipocytes might result in enhancement of insulin-stimulated GLUT4 externalization.