BACKGROUND: Cholangiocarcinoma (CCA) is a highly fatal tumor, and the most favorable chance for long-term survival lies in curative resection. Periductal fibrosis (PDF), a precancerous condition associated with chronic inflammation of the bile ducts, can serve as a screening marker for CCA using hepatobiliary ultrasonography (US). However, limited studies have explored the relationship between PDF and CCA. This study aimed to investigate the association between PDF and CCA in a population at risk in Northeast Thailand.
METHODS: The study included participants enrolled in the Cholangiocarcinoma Screening and Care Program (CASCAP) between 2013 and 2021 who underwent US. Histological evaluations were conducted following the standard protocol of the tertiary hospital at Khon Kaen University, Thailand. PDF was defined as the presence of fibrosis in the peripheral (PDF1), segmental (PDF2), or main bile duct (PDF3), diagnosed by well-trained general practitioners or radiologists. The association between PDF and CCA was assessed using multiple logistic regression, calculating adjusted odds ratios (AORs) and 95% confidence intervals (CIs).
RESULTS: Out of 751,061 participants, the overall prevalence of PDF was 115,267 (15.35%), with an overall CCA rate of 0.11%. The rates of CCA were 0.1%, 0.15%, and 0.27% in participants with PDF1, PDF2, and PDF3, respectively. After adjusting for gender, age at enrollment, education levels, history of O. viverrini infection, smoking, and alcohol consumption, the AORs for CCA were 0.94 (95% CI: 0.74 - 1.20), 1.4 (95% CI: 1.03 - 1.91), and 2.52 (95% CI: 1.38 - 4.58) for participants with PDF1, PDF2, and PDF3, respectively.
CONCLUSIONS: Our findings demonstrate a significant association between fibrosis of the segmental and main bile ducts (PDF2 and PDF3) and CCA, with the strongest association observed in participants with PDF3. Hepatobiliary US screening could serve as a valuable tool for early detection of CCA, enabling timely curative treatment.

BACKGROUND: Cholangiocarcinoma (CCA) has been categorized based on tumor location as intrahepatic (ICCA), perihilar (PCCA) or distal (DCCA), and based on the morphology of the tumor of the bile duct as mass forming (MF), periductal infiltrating (PI) or intraductal (ID). To date, there is limited evidence available regarding the survival of CCA among these different anatomical and morphological classifications. This study aimed to evaluate the survival rate and median survival time after curative surgery among CCA patients according to their anatomical and morphological classifications, and to determine the association between these classifications and survival.
METHODS: This study included CCA patients who underwent curative surgery from the Cholangiocarcinoma Screening and Care Program (CASCAP), Northeast Thailand. The anatomical and morphological classifications were based on pathological findings after surgery. Survival rates of CCA and median survival time since the date of CCA surgery and 95% confidence intervals (CI) were calculated. Multiple cox regression was performed to evaluate factors associated with survival which were quantified by hazard ratios (HR) and their 95% CIs.
RESULTS: Of the 746 CCA patients, 514 had died at the completion of the study which constituted 15,643.6 person-months of data recordings. The incidence rate was 3.3 per 100 patients per month (95% CI: 3.0-3.6), with median survival time of 17.8 months (95% CI: 15.4-20.2), and 5-year survival rate of 24.6% (95% CI: 20.7-28.6). The longest median survival time was 21.8 months (95% CI: 16.3-27.3) while the highest 5-year survival rate of 34.8% (95% CI: 23.8-46.0) occurred in the DCCA group. A combination of anatomical and morphological classifications, PCCA+ID, was associated with the longest median survival time of 40.5 months (95% CI: 17.9-63.0) and the highest 5-year survival rate of 42.6% (95% CI: 25.4-58.9). The ICCA+MF combination was associated with survival (adjusted HR: 1.45; 95% CI: 1.01-2.09; P = 0.013) compared to ICCA+ID patients.
CONCLUSIONS: Among patients receiving surgical treatment, those with PCCA+ID had the highest 5-year survival rate, which was higher than in groups classified by only anatomical characteristics. Additionally, the patients with ICCA+MF tended to have unfavorable surgical outcomes. Showed the highest survival association. Therefore, further investigations into CCA imaging should focus on patients with a combination of anatomical and morphological classifications.