Stage 0 cancer is referred to as carcinoma in situ, which is cancer that involves only the superficial layer of cells lining the stomach.
Stage I gastric cancer is cancer that invades beneath the surface layer of cells lining the stomach. The cancer is referred to as Stage IA if the cancer does not involve the bladder muscle and has not spread to lymph nodes or distant sites in the body. The cancer is referred to as Stage IB if the cancer involves either the bladder muscle or 1 to 2 lymph nodes.
Surgery as Primary Treatment
Surgery is the primary treatment for early-stage gastric cancer. Depending on the extent and location of the cancer, surgery may involve endoscopic mucosal resection (use of an endoscope to view and remove only the cancerous area), removal of part of the stomach (subtotal gastrectomy), or removal of the entire stomach (total gastrectomy). Patients often have several surrounding lymph nodes removed as well, although there continues to be debate about how extensive this lymph node removal should be.
Patients with Stage I gastric cancer should consider treatment at a medical center with a surgical team that has experience and treats a large number of patients with gastric cancer each year.
Patients who cannot undergo the usual surgical resection of cancer can have small superficial gastric cancers removed through an endoscope passed through the esophagus. However, this approach precludes lymph node sampling or removal.
Bang Y-J, Van Cutsem E, Feyereislova A et al. Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial. Lancet. 2010; 376:687-697.