Recent trends in the morbidity and mortality in patients with familial adenomatous polyposis: a retrospective single institutional study in Japan

Background This study aimed to assess current trends in morbidity and mortality among patients with familial adenomatous polyposis (FAP). These data can be used for optimal surveillance and management of such patients. Methods Data (November 2001 and April 2020) of genetically confirmed patients with FAP ( n = 87) and their first-degree relatives with FAP phenotype ( n = 20) were extracted from the Saitama Medical Center database. Standardized mortality ratio (SMR) and standardized incidence ratio (SIR) were estimated using indirect method. Results Overall, 46 men and 61 women were included; the median age at FAP diagnosis was 28.0 years for both. The SMR for all causes of death was 47.7 (95% confidence interval [CI] 19.1–98.2) in women and 26.5 (95% CI 9.73–57.8) in men. The SIR for colorectal cancer (CRC) was 860 (95% CI 518–1340) in women and 357 (95% CI 178–639) in men. The SMR for CRC was 455 (95% CI 93.7–1330) in women and 301 (95% CI 62.0–879) in men. Thirteen patients died during the observation period, and CRC was the leading cause of death (46%). Other causes of death included desmoid tumor ( n = 2), small intestinal cancer ( n = 2), ovarian cancer ( n = 1), duodenal cancer ( n = 1), and sepsis ( n = 1). Conclusions The mortality ratio, estimated using SMR, remained high. CRC was the leading cause of death, whereas almost half of the causes of deaths were extra-colonic tumors. Life-long management of extra-colonic diseases may improve the prognosis in these patients.