Although the incidence of gastric cancer has decreased because of the lower rate of Helicobacter pylori infection, it still accounts for a large number of deaths in Japan. Gastric cancer is mainly treated by resection, and the rate of radical resection is high in Japan because approximately 50% of cases are diagnosed at an early stage. Treatment advances have increased the number of endoscopic submucosal dissections, and development of laparoscopic surgery and robot-assisted surgery as minimally invasive approaches has yielded results similar to those of conventional surgeries, at least in the short term. Cases for which resection is contraindicated are treated with chemotherapy if performance status can be maintained. Although anticancer drugs are continuously under development, treatment outcomes remain unsatisfactory. As Japan becomes a super-aging society, the number of refractory cases is projected to increase. Therefore, evidence of any benefit for minimally invasive surgery and function-preserving surgery needs to be reported quickly. In this paper, we discuss gastric cancer treatment modalities recommended in the fifth edition of the gastric cancer treatment guidelines and describe recent research findings.
Keywords: chemotherapy; endoscopic resection; gastric cancer; surgical resection.