Accelerated Premalignant Polyposis and Second Colon Cancers: Incriminating Immunosuppression, Radiotherapy, and Systemic Chemotherapy Agents.

BACKGROUND: Cancer survivors are known to be at increased risk for second primary cancers. In addition, immunosuppression and previous cancer treatments such as radiotherapy and systemic chemotherapy are linked with increased risk of both colonic adenomas and adenocarcinomas. AIM: We performed a systematic review searching for manuscripts discussing second colon cancers, accelerated polyposis, immunosuppression, radiation, and chemotherapy. We sought to identify a link between immunosuppression and increased risks specific to premalignant polyposis and second colon cancers.
FINDINGS: We identified multiple studies demonstrating associations between radiotherapy, systemic chemotherapy, and immunosuppression with a higher propensity for second colon adenomas and adenocarcinomas. When compared to the general population, these risks were more profound and the rate at which these second malignancies developed was significantly increased.
CONCLUSIONS: We believe that timing for colonoscopic surveillance in these patients should be different from the general population in order to identify promptly these rapidly progressive neoplasms. Screening for second malignancies should be considered early after remission of the primary cancer is documented, especially when a prolonged survival or a cure is anticipated. We also recommend consideration be given to increasing the frequency of colonoscopy in these cohorts. Future studies are required in order to establish the optimal time interval for surveillance colonoscopy in these high-risk individuals.