RESUMEN
PURPOSE: The purpose of this study was to analyze the characteristics, diagnosis and treatment principles and prognosis of multiple primary cancers (MPC). METHODS: A total of 77 patients with MPC admitted in the Central Hospital of Changsha from December 2013 to December 2018 were enrolled in this retrospective analysis. The survival of these 77 patients with complete follow-up data was calculated. RESULTS: There were 77 patients with multiple primary cancers, including 70 patients with double primary cancers, 6 patients with three primary cancers, and 1 patient with four primary cancers. Among the 77 MPC patients, there were 4 synchronous carcinomas (SC), 58 metachronous carcinomas (MC), and 15 unknown cases. The 3, 5, and 10-year overall survival rates of 77 patients with follow-up data were 86.5%, 18.2%, and 12.9%, respectively. The median survival time of 4 SC and 58 MC patients was 12 months and 108 months, respectively. The median survival time was 48.5 months in 23 patients with an interval of less than 5 years, and 108 months in 29 patients with first and second primary cancers whose interval was more than 5 years. The median survival time of 26 patients with second primary lung cancer was 84 months, and that of 23 patients with second primary non-lung cancer was 156 months. CONCLUSIONS: MPCs are more likely to occur in the colorectum, and the prognosis of patients with metachronous cancer is better than that of patients with synchronous cancer. The longer the interval between two cancers, the better the prognosis will be. The prognosis of the second primary non-lung cancer patients is better than that of the lung cancer patients.