Takeshi Miyama

Basaloid‐Squamous Carcinoma of the Esophagus with Marked Deposition of Basement Membrane Substance

A 71 year old Japanese man with basaloid‐squamous carcinoma of the esophagus is reported. The carcinoma contained basaloid cells, a few small cornified foci, and a large amount of eosinophilic hyaline substance, which reacted positively upon periodic acid Schiff, type IV collagen, and laminin staining. Ultrastructural examination revealed markedly replicated basement membranes (BM). The morphological findings suggested that this tumor secreted abundant BM substance. Small nests of cancer cells were attached to the dysplastic esophageal epithelium. The tumor cells exhibited negative staining for mucin, secretory component, lactoferrin, and carcinoembryonic antigen. These findings, as well as the observed keratini‐zation and attachment between the carcinoma nests and mucosal epithelium, indicate that the tumor originated in the mucosal epithelium of the esophagus. Acta Pathol Jpn 41: 59–64, 1991.

Activities of thymidylate synthetase and thymidine kinase in gastric cancer

In a previous clinical study, sequential methotrexate and 5-fluorouracil has shown improved efficacy for treating advanced gastric cancer of the poorly differentiated type. In this study, we investigated whether difference in the levels of thymidylate synthetase (TS) and thymidine kinase (TK) activities in gastric cancer tissue account for selectivity of the treatment. Activity of TS was higher in 19 cases of the poorly differentiated type than in 16 cases of the well differentiated type (P < 0.02), whereas TK activity was lower in the poorly differentiated type than in the well differentiated type (P < 0.01). Thus, the TS/TK ratio was significantly higher in poorly differentiated gastric cancers than in well differentiated cancers (P < 0.001). These results suggest that a greater dependence upon the de novo pathway of pyrimidine synthesis in poorly differentiated gastric carcinomas may enhance the efficacy of sequential methotrexate and 5-fluorouracil treatment.

Gastroesophageal Reflux After Gastric Surgery

Esophageal and gastric pH monitoring and endoscopic examination of the esophagus were performed in patients after gastric surgery. The duration time and frequency of gastroesophageal reflux were studied using an ambulatory 24-h pH monitoring system. The subjects consisted of 43 patients with distal gastrectomy, 3 patients with proximal gastrectomy, 19 patients with total gastrectomy, 9 patients with reflux esophagitis without previous gastric surgery, and 53 preoperative patients. Esophageal and gastric pH were measured 5 cm above and 5 cm or 10 cm below the esophagogastric junction (EGJ). The duration, ratio and frequency of acid (pH 7.4) reflux, acid and alkaline clearance time, and mean and median pH were measured. From the pattern of the esophageal pH curve, patients were divided into four groups: normal, acid reflux, alkaline reflux, and mixed type. In patients who received distal gastrectomy, acid reflux time (pH 7.4) and alkaline clearance time were longer than in preoperative patients. There were a few patients who showed small changes in esophageal pH in spite of esophagitis; the esophagitis in these patients was considered to be due to pancreatic enzymes.

Leucovorin, Cisplatin, and 5-Fluorouracil for Advanced Esophageal Cancer

Biochemical modulation involves the use of one drug (modulating agent; modulator) to change the pharmacokinetics and/or pharmacodynamics of a cytotoxic agent (effector), in a way that the therapeutic index of the effector is enhanced [1]. The modulator is often also a cytotoxic agent, but a non-cytotoxic agent like leucovorin is sometimes used as well. The modulating agent improves selectivity or sensitivity of an effector and decreases its toxicity to normal cells via a biochemical or metabolical mechanism. Currently, several biochemical modulations such as the sequential methotrexate (MTX)/5-fluorouracil (5-FU), leucovorin (LV)/5-FU, and cisplatin (CDDP)/5-FU have been evaluated clinically in terms of their efficacy for alimentary tract malignancies.

Endoscopic Treatment for the Cancer and Submucosal Tumor of the Upper Gastrointestinal Tract

Endoscopic treatment was performed for 38 patients of gastric cancer and 6 patients of esophageal cancer and 3 patients of submucosal tumor of the upper gastrointestinal tract. Thirty-four patients of gastric cancer were treated by laser irradiation. In these patients, 26 were considered as early cancer, and 8 were considered as advanced cancer. Four patients of gastric cancer and one patient of esophageal cancer were treated by strip biopsy. All these patients were considered as intolerable for surgical operation or refused for operation. In the laser therapy, Nd:YAG laser irradiation of 40–90 watts with 1–0.5 second duration was repeated for the lesions. The prognosis of early gastric cancer was good in case of protruded type or small ulcerative type which was less than 2cm in diameter. Three patients of subumcosal tumor of the upper GI tract were treated by laser and electro-surgery. The lesion was in the esophagus, stomach and duodenum. KTP laser with bare quartz fiber of 0.3 mm in diameter was used. The surface of mucosal layer was cut with laser at the base of the tumor. Then the tumor was grasped by forceps and resected by electro-surgery. The resected specimens revealed myoma of the esophagus, fibrosis with calcified tissue of the stomach, and lipoma of the duodenum.