Simultaneous Occurrence of Early Gastric Carcinoma in Identical Twins

Recently, we encountered a case of simultaneous occurrence of early gastric cancer in twins. This is the third case report of gastric carcinoma in identical twins in Japan. Case 1: A 38-year-old housewife visited Juntendo University, School of Medicine, Urayasu Hospital in Chiba Prefecture. An upper gastrointestinal barium X-ray and gastrofiberscopy revealed early gastric cancer at the anterior wall of the stomach angle. Biopsy materials showed signet-ring cell carcinoma. On march 25 1987, Billroth I subtotal gastrectomy was performed at Juntendo University, School of Medicine, Urayasu Hospital, Department of Surgery. Case 2: A 38-year-old housewife was asked to undergo evaluation of her stomach because her twin sister had had gastric surgery for early gastric cancer that month. An upper gastrointestinal barium X-ray showed only mild gastritis. Due to the fact that her twin sister had early gastric cancer, the patient persisted to have further gastric examination. Subsequently, gastrofiberscopy was performed and biopsy materials revealed signet-ring cell carcinoma of the stomach angle. On May, 1987, we performed Billroth I distal gastrectomy. Postoperatively, we examined the HLA type and blood groups of the twins. Typing for HLA and blood groups of the twins showed no difference. These results confirmed that the twins were truly monozygotic twins. The genetic factor in gastric carcinoma is of considerable importance for oncogenic research.