Malignant tumors associated with juvenile polyposis syndrome in Japan

The risk of malignant tumors developing in association with juvenile polyposis syndrome (JPS) was evaluated to explore the optimal treatment for this rare disease. We reviewed the data on JPS cases reported in Japan between January, 1971 and March, 2016. A total of 171 cases were evaluable. Of these 171 patients, 83 (48.5%) were female and the median age at diagnosis was 28 years (range 1-80 years). The polyps were located in the stomach alone (n = 62; 36.3%), in the stomach and intestine (n = 47; 27.4%), or in the colorectum alone (n = 62; 36.3%). The sites of malignant tumors were the stomach (n = 31), colorectum (n = 29), small intestine (n = 2), breast (n = 1), and thyroid (n = 1). The lifetime risk (at 70 years) of any malignant tumor was 86.2%. The lifetime risk of gastric cancer was 73.0% and that of colorectal cancer was 51.1%. The risk of these cancers developing was dependent on the type of polyp distribution. Long-term surveillance of the stomach and colorectum based on the phenotype of JPS seems a reasonable approach to monitor these patients for the development of malignant tumors.