Mitani S, Kadowaki S, Oze I, et al. - After definitive therapy for esophageal cancer, researchers clarified the frequency of and risk factors for the second malignancies. Between 2000 and 2010, patients with esophageal cancer who received definitive therapy were included. Using age- and sex-specific incidence rates from the cancer registry data, standardized incidence rate was calculated. In total, 758 individuals were involved, with 131 second malignancies occurring in 106 individuals, over a median follow-up of 3.7 years. After 3, 5, and 8 years, cumulative incidences of second malignancies were 4.0%, 7.6%, and 13.8%, respectively. Head and neck, followed by the lung, stomach, colon and rectum, and urinary tract were the most common sites of primary tumor. An increased incidence of second malignancies was noted in the patients with esophageal cancer even after definitive treatment compared with the general population. Careful follow-up is needed, particularly in patients with a higher risk of second malignancies.