Prognostic impact of hospital volume on familial adenomatous polyposis: a nationwide multicenter study.

PURPOSE: Many studies have shown that hospital volume is significantly associated with short- and long-term outcomes in various diseases, including cancer. However, there have been no reports discussing the relationship between hospital volume and familial adenomatous polyposis (FAP). This study aimed to clarify whether hospital volume affects short- and long-term outcomes in FAP patients.

METHODS: We established a retrospectively collected database of FAP patients who underwent initial surgical treatment at 23 Japanese institutions during 2000-2012. Factors associated with short- and long-term outcomes were analyzed.

RESULTS: The study cohort included 303 FAP patients. These patients were classified into tertile categories according to hospital volume: low (n = 31), middle (n = 72), and high volume (n = 200). The proportion of only adenoma/stage 0 was comparable among tertile categories. The adoption of operative procedure significantly differed among tertile categories; specifically, high-volume institutions preferred handsewn ileal pouch-anal anastomosis without diverting ileostomy (P < 0.001 and < 0.001, respectively). Nevertheless, the frequency of complications with Clavien-Dindo classification grade ≥ 3 was not significantly different among tertile categories. Functional results were acceptable in every category. Wexner scores were significantly lower in high-volume compared to low-volume institutions (P = 0.02). Multivariate analyses showed that UICC stage and hospital volume were significantly associated with overall survival (P = 0.04 and 0.03, respectively).

CONCLUSIONS: Hospital volume was significantly associated with short- and long-term outcomes in FAP patients.