Management of Superficial Esophageal Squamous Cell Carcinoma and Early Gastric Cancer following Non-Curative Endoscopic Resection

SIMPLE SUMMARY: Guidelines recommend additional treatment following non-curative endoscopic resection in cases of superficial esophageal squamous cell carcinoma and early gastric cancer because of the potential risk of lymph node metastasis. This review discusses recent advances in this field, including the development of pathological risk stratification for metastatic recurrence and identification of different recurrence patterns after non-curative endoscopic resection for superficial esophageal squamous cell carcinoma or early gastric cancer, and the establishment of a novel treatment strategy for clinical T1b-SM esophageal squamous cell carcinoma. For optimal therapeutic decision-making in such patients, it is also important to predict prognoses other than superficial esophageal squamous cell carcinoma or early gastric cancer and impaired quality of life. Thus, a novel algorithm that considers these factors and metastatic recurrence is required. ABSTRACT: According to the European and Japanese guidelines, additional treatment is recommended for cases of superficial esophageal squamous cell carcinoma (ESCC) and early gastric cancer (EGC) that do not meet the curability criteria for endoscopic resection (ER), i.e., non-curative ER, owing to the risk of lymph node metastasis (LNM). However, the rates of LNM in such cases were relatively low (e.g., 8% for EGC). Several recent advances have been made in this field. First, pathological risk stratification for metastatic recurrence following non-curative ER without additional treatment was developed for both superficial ESCC and EGC. Second, the pattern of metastatic recurrence and prognosis after recurrence following non-curative ER without additional treatment was found to be considerably different between superficial ESCC and EGC. Third, a combination of ER and selective chemoradiotherapy was developed as a minimally invasive treatment method for clinical T1b-SM ESCC. These findings may help clinicians decide the treatment strategy for patients following non-curative ER; however, for optimal therapeutic decision-making in such patients, it is also important to predict the prognosis other than SESCC or EGC and impaired quality of life. Thus, a novel algorithm that considers these factors, as well as metastatic recurrence, should be developed.