Current clinical practice for familial adenomatous polyposis in Japan: A nationwide multicenter study

Abstract

Abstract Introduction In Japanese patients with familial adenomatous polyposis (FAP), colectomy tends to be postponed or avoided. Aim This study aimed to clarify the current clinical practice from a Japanese multicenter cohort study database. Methods We analyzed the records of 250 patients with non‐dense FAP who did not require colorectal cancer removal. The clinical outcomes were compared between patients who received colectomy (n = 142) (Group A) and those who did not receive colectomy (n = 108) (Group B). Results The colectomy rate based on the age at the final follow‐up examination was 46%, 60%, 54%, 65%, at ≤29, 30–39, 40–49, and ≥ 50 years, respectively ( P = .11). The development of colorectal cancer did not differ between Groups A and B (25% vs 22% P = .67); however, colorectal cancer was diagnosed at the Tis stage in 88% of the patients with colorectal cancer in Group B, and 34% of the patients with colorectal cancer in Group A ( P < .01). Regarding survival, all patients in Group B were alive at the final follow‐up examination. In contrast, six patients in Group A died, including three patients with desmoid tumors and one with colon cancer. Conclusion Over one‐third of patients with non‐dense FAP (polyps ≤ 1000) in Japan did not receive colectomy at >30 years of age, and patients who managed without colectomy showed acceptable survival with the early diagnosis of colorectal cancer, and a very low incidence of desmoid tumor development, indicating that this approach represents a potential option for the management of selected non‐dense FAP patients.