IgG4‐related sclerosing cholangitis may be a risk factor for cancer
Yusuke Kurita, Yuji Fujita, Yusuke Sekino, Seitaro Watanabe, Akito Iwasaki, Koichi Kagawa, Emiko Tanida, Shin Yagi, Sho Hasegawa, Takamitsu Sato, Kunihiro Hosono, Shingo Kato, Noritoshi Kobayashi, Yasushi Ichikawa, Itaru Endo, Atsushi Nakajima, Kensuke Kubota
Abstract
BACKGROUND/PURPOSE: The relationship between autoimmune pancreatitis (AIP) and malignancy has been reported. However, the potential risk for cancer in patients with immunoglobulin 4 (IgG4)-related sclerosing cholangitis (IgG4-SC) is unclear. The present study aimed to evaluate the incidence of cancer in IgG4-SC patients. METHODS: We retrospectively collected clinical data for 121 patients diagnosed with IgG4-SC from 7 hospitals. We calculated the standardized incidence ratio (SIR) of cancer in IgG4-SC patients based on the national cancer rates. The SIR of the period after the diagnosis of IgG4-SC were calculated. RESULTS: The mean follow-up period was 6.4 years, with 121 IgG4-SC patients. During the follow-up period, 26 patients had cancer, and 29 cancers were diagnosed. The SIR of cancer after the diagnosis of IgG4-SC was 1.90 (95% confidence interval [CI] 1.67-2.21). The SIR of pancreatic and bile duct cancer was 10.30 and 8.88, respectively. The SIR of cancer in <1 year, 1-5 years, and >5 years after diagnosis of IgG4-SC were 2.58, 1.01, and 2.44, respectively. CONCLUSIONS: IgG4-SC patients have a high risk of cancer including pancreatic and bile duct cancer. The risk of cancer was high less <1 year and >5 years after diagnosis of IgG4-SC. Therefore, IgG4-SC patients may require careful long-term follow-up.