Localized gastric or gastroesophageal cancer - chemoradiation is a pertinent component of adjuvant treatment for patients at high risk of relapse.

The standard of care for resectable gastric or gastroesophageal (GE) junction cancer for patients who can tolerate a surgical procedure is surgical resection, but surgery alone is not optimal treatment for patients at high risk for relapse. For patients with lower-risk lesions (confined to gastric wall, nodes negative; T1-2N0M0), local-regional relapse risks are low, and adjuvant radiotherapy is usually not recommended, except in select instances. Since both local-regional and systemic relapses are common after resection of high-risk gastric or GE junction cancers (beyond wall, nodes positive, or both; T3-4N0, TanyN+), adjuvant treatment is indicated for these patients. The results of phase III trials that demonstrate a survival benefit for adjuvant preoperative radiotherapy, postoperative chemoradiation, or preoperative chemoradiation vs. surgery alone will be presented and compared with the results of adjuvant perioperative chemotherapy. Results of Surveillance, Epidemiology, and End Results (SEER) analyses and meta-analyses that support the role of adjuvant radiotherapy or chemoradiation will be summarized.