[A case of metastatic bladder cancer occurring after surgery for differentiated gastric cancer controlled by combination therapy of paclitaxel/S-1].

Abstract A 70-year-old male visited the hospital with a complaint of stomachache. Hydronephrosis was observed in the right kidney, and further examination confirmed a diagnosis of metastatic cancer limited to the bladder and rectovesical pouch after surgery for differentiated gastric cancer. Chemotherapy using paclitaxel(PTX)/S-1 was initiated. One course included 14 days of administration of S-1 (100 mg/body) followed by a 7-day interval, and the administration of PTX (60 mg/body) on the 1st and 15th days. General malaise developed after 4 courses, the dose of S-1 was reduced (80 mg/body), and PTX was administered only on the 1st day. CT conducted 9 months after the start of chemotherapy revealed the disappearance of ascites, decreased thickness of the bladder wall, and reduced size of the tumor in the rectovesical pouch. No new distal metastasis or peritoneal metastatic nodule has been observed, and there has been no tendency toward exacerbation for one year after the initial diagnosis. PTX/S-1 was suggested to be an effective treatment for metastatic cancer limited to the bladder and rectovesical pouch after surgery for differentiated gastric cancer.