Chronological Changes in Early Gastric Cancer Progressing to a Large, Unresectable Type 3 Tumor with Peritoneal Metastasis: A Case Report

in Early to A Abstract Background: The standard management of gastric cancer is complete resection if the lesion can be removed by surgery or endoscopic resection. Occasionally, some patients with gastric cancer are followed up without treatment for various reasons. However, there is little information about the natural course of gastric cancer, especially concerning the onset of symptoms. We herein report the chronological changes in a patient with asymptomatic early gastric cancer progressing to symptomatic unresectable advanced cancer. Case Presentation: A 68-year-old man presented with epigastralgia. Esophagogastroduodenoscopy revealed a depressed lesion 35 mm in diameter at the lesser curvature of the upper gastric body (lesion 1) and a depressed lesion 40 mm in diameter at the posterior wall of the lower gastric body (lesion 2). The lesions were diagnosed as synchronous multifocal early gastric cancers, cT1bN0M, and cStage I, consisting of lesion 1 (U, Less, cT1b) and lesion 2 (M, Less, cT1a). Surgical treatment was strongly recommended, but he selected observation without any treatment. He received periodic follow-up every six months. The tumor progressed to a type 2 lesion after two years and then a type 3 lesion after two and half years. At three years and nine months from the initial diagnosis, he requested treatment because of anorexia and weight loss of 5 kg. Gastric wall thickening and regional lymph node swelling were detected by computed tomography. Staging laparoscopy revealed massive peritoneal metastasis. The postoperative diagnosis was cT4aN+M1P1 and cStage IVB, and systemic chemotherapy was indicated. Conclusion: Observation may be reasonable in asymptomatic patients with locally advanced gastric cancer who are expected to live for at least one year.