Timing of prophylactic colectomy in familial adenomatous polyposis.

Abstract

The aim was to evaluate the timing of prophylactic colectomy in patients with familial adenomatous polyposis (FAP) in Finland. All Finnish FAP patients were included from the years 1963-2018. Among the 452 FAP patients studied, 252 were called up as relatives of the proband. Of these, 180 underwent prophylactic colectomy. Patient data including mutation characteristics and surgical technique were collected. We assessed the timing of prophylactic colectomy in relation to the time of diagnosis, time of decision for surgery and age. There were 94 (52%) colectomies with ileorectal anastomosis, 79 (44%) proctocolectomies with ileal pouch-anal anastomosis and seven (4%) proctocolectomies with an ileostomy. Median age at diagnosis and at the time of surgery was 20.9 and 25.2years, respectively. The median time from decision to operate to undergoing surgery was 4months. There were eight (4%) cancers in the colectomy specimens, but none was found during the annual follow-ups after the first-round endoscopy. After genetic testing became available, the diagnosis was made primarily by either genetic testing in 52 (49%) or endoscopy in 54 (51%) patients at a median age of 17.8 and 19.3years, respectively. Thirty-eight (21%) patients died during follow-up, 23 (61%) for FAP-related reasons and only six from rectal cancer. The relative survival of 30years from diagnosis was 84% and 78% in men and women, respectively. For those who underwent surgery, timing of prophylactic surgery was successful as there were no unexpected colorectal cancers found in colectomy specimens among the screened patients. Two major improvements over the study period have changed the treatment of FAP patients: one is the introduction of the ileal pouch-anal anastomosis procedure and the other is the availability of genetic testing. FAP-related extra-colonic malignancies affect the relative survival of these patients after prophylactic surgery.