BACKGROUND: The frequency of isolated biliary candidiasis is increasing in cancer patients. The clinical significance of isolated biliary candidiasis remains unclear. We analyzed the risk factors of biliary candidiasis and outcomes of the patients with unresectable cholangiocarcinoma after percutaneous transhepatic biliary drainage (PTBD).

METHODS: Among 430 patients who underwent PTBD between January 2012 and March 2015, 121 patients had unresectable cholangiocarcinoma. Bile and blood samples were collected for consecutive fungal culture.

RESULTS: The study cohort included 49 women and 72 men with a median age of 71 years. Multivariate analysis showed that cancer progression (P=0.013), concurrent presence of another microorganism (P=0.010), and previous long-term (>7 days) antibiotic use (P=0.011) were potential risk factors of biliary candidiasis. Chemotherapy was not associated with overall biliary candidiasis (P=0.196), but was significantly related to repeated biliary candidiasis (P=0.011). Patients with isolated biliary candidiasis showed remarkably reduced survival compared with those without [median overall survival (OS): 32 vs 62 days, P=0.011]. Subgroup analysis was also performed. Patients with repeated candidiasis had markedly decreased survival compared with those with transient candidiasis (median OS: 30 vs 49 days, P=0.046). Biliary candidiasis was identified as a poor prognostic factor by univariate and multivariate analyses (P=0.033). Four cases of repeated candidiasis (4/19, 21%) showed Candida species in consecutive blood culture until the end of the study, but others showed no candidemia.

CONCLUSIONS: Isolated biliary candidiasis may be associated with poor prognosis in patients with unresectable cholangiocarcinoma. Especially, repeated biliary candidiasis may have the possibility of progression to candidemia. We suggest that biliary dilatation treatment or antifungal agents might be helpful for patients with biliary candidiasis.