Characteristics of Anal Fistula Cancer in Patients Who Underwent Surgery: A Nationwide Observational Study Using...

Anal fistula cancer is a rare disease that occurs in < 1% of patients with anal fistulas. The clinical characteristics of anal fistula cancer are not fully understood. This study aimed to identify the characteristics of patients with anal fistula cancer by comparing them with those of patients with anal canal or rectal cancer.

This was a nationwide observational study using the Diagnosis Procedure Combination data. Patients who underwent abdominoperineal resection or total pelvic exenteration for anal fistula, anal canal, or rectal cancer were included in this study. Patient background, surgical outcomes, postoperative complications, and medical costs were compared among the three types of cancer.

This study included 206 patients with anal fistula cancer, 1207 patients with anal canal cancer, and 18 254 patients with rectal cancer. Patients with anal fistula cancer were more likely to be male, younger, or smokers. In patients with anal fistula cancer, the proportion of open surgeries was significantly higher, and the length of hospital stay was significantly longer than in those with anal canal and rectal cancer. Anal fistula cancer tended to be more locally advanced than other cancers, whereas lymph node and distant metastases were less common. The incidence of incisional wound infection and wound dehiscence was significantly higher, and medical costs were the highest in patients with anal fistula cancer.

Anal fistula cancer is characterized by aggressive local progression, resulting in a higher frequency of open surgery, a higher incidence of wound-related complications, and higher medical costs.