Adenocarcinoma within anorectal fistulae: different clinicopathological characteristics between Crohn's disease-associated type and the usual type

Abstract

Adenocarcinoma within anorectal fistulae is rare and is sometimes associated with Crohn's disease. Crohn's disease-associated adenocarcinoma within anorectal fistulae has a poor prognosis; however, little is known about the clinicopathological differences between Crohn's disease-associated adenocarcinoma within anorectal fistulae and usual adenocarcinoma within anorectal fistulae. We retrospectively searched patients' charts and pathology archives at Tokyo Yamate Medical Center and Tokyo Medical and Dental University Hospital for adenocarcinoma within anorectal fistulae. Clinical and pathological data were collected and immunohistochemical examinations were conducted. Overall survival rate was estimated using the Kaplan-Meier method. Prognostic factors of overall survival were assessed using univariate and multivariate Cox regression analyses. We examined 82 cases of adenocarcinoma within anorectal fistulae. Fifty-nine of 82 cases (72%) had usual adenocarcinoma within anorectal fistulae, while the remaining 23 cases (28%) had Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae were diagnosed at a younger age and at a more advanced stage than those with usual adenocarcinoma within anorectal fistulae. Macroscopic and histological types were also different between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Crohn's disease-associated adenocarcinoma within anorectal fistulae included more ulcerative types and high-grade adenocarcinomas. The rate of lymphovascular invasion was higher in Crohn's disease-associated adenocarcinoma within anorectal fistulae. Immunohistochemically, the expression of E-cadherin, p53, and MUC5AC differed between usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae. Patients with Crohn's disease-associated adenocarcinoma within anorectal fistulae exhibited worse overall survival than those with usual adenocarcinoma within anorectal fistulae, and vascular invasion was the strongest significant independent predictor of overall survival in patients with adenocarcinoma within anorectal fistulae. In conclusion, usual adenocarcinoma within anorectal fistulae and Crohn's disease-associated adenocarcinoma within anorectal fistulae have different clinicopathological characteristics and should be considered separate clinical entities.

Outcomes of surgical treatment in patients with anorectal fistula cancer

“…The major histologic type of anorectal fistula cancer has been reported to be mucinous cancer [17]. Our study also found that mucinous cancer was the most frequent type of histology.…”

“…It can be speculated that FDG is more likely to accumulate in anorectal fistula cancer, unlike normal mucinous cancer, because the tumor contains sites of inflammation [20]. Kodama et al report that anorectal fistula cancer associated with Crohn's disease has a worse prognosis than usual anorectal fistula cancer [17]. It has been reported that the expression of epithelial-to-mesenchymal transition-related protein is enhanced in the anorectal fistula cancer in Crohn's disease, thus increasing the likelihood for metastasis [21].…”

Cancer in Anal Fistulas

“…8 Other adenocarcinoma subtypes have been identified, including mucinous and tubular, with mucinous being the most common. 9,10 In the available literature, tubular carcinoma has been associated with lower grade tumors, though there have been very few reported cases available. 9 Mucinous adenocarcinomas meanwhile have been shown to have deeper invasion on histology when compared with tubular adenocarcinomas.…”

“…28 Regarding prognosis, Kodama et al found that anal adenocarcinoma arising from CD-related fistula appears to behave significantly different when compared with anal cancer arising from a non-CD fistula and have suggested that it should be categorized as its own entity. 9 Its unique behavior and features have been identified as the main reason behind the poor prognosis. When compared with non-CD FAAC, anal cancer arising from CD-related fistula exhibits lower overall survival rate.…”

Clinicopathological and prognostic evaluations of anorectal cancer after fecal diversion for patients with Crohn's disease

“…Although the risk of colorectal cancer (CRC) has been well described, the risk of CRC in diverted bowel segments is lacking, and the current risk remains unclear [1]. Typically, CDassociated cancers present in advanced stages are poorly differentiated and have a worse prognosis than usual adenocarcinoma [2][3][4][5]. For this reason, surveillance colonoscopy is necessary to detect cancer at an early stage.…”