Predicting risk of recurrence after resection of stage I intrahepatic cholangiocarcinoma

BACKGROUND: Early-stage intrahepatic cholangiocarcinoma (ICC) is often an indication of curative-intent resection. Although patients with early-stage ICC generally have a better prognosis than individuals with advanced ICC, the incidence and risk factors of recurrence after early-stage ICC remain unclear. METHODS: A multi-institutional database was used to identify patients who underwent surgery between 2000 and 2018 for ICC with pathologically confirmed stage I disease. Cox regression analysis was used to identify clinicopathological factors associated with recurrence, and an online prediction model was developed and validated. RESULTS: Of 430 patients diagnosed with stage I ICC, approximately one-half of patients (n = 221, 51.4%) experienced recurrence after curative-intent resection. Among patients with a recurrence, most (n = 188, 85.1%) experienced it within 12 months. On multivariable analysis, carcinoembryonic antigen (hazard ratio [HR], 1.011; 95% CI, 1.004-1.018), systemic immune-inflammation index (HR, 1.036; 95% CI, 1.019-1.056), no lymph nodes evaluated (HR, 1.851; 95% CI, 1.276-2.683), and tumor size (HR, 1.101; 95% CI, 1.053-1.151) were associated with greater hazards of recurrence. A predictive model that included these weighted risk factors demonstrated excellent prognostic discrimination in the test (12-month recurrence-free survival [RFS]: low risk, 80.1%; intermediate risk, 60.3%; high risk, 37.7%; P = .001) and validation (12-month RFS: low risk, 84.5%; intermediate risk, 63.5%; high risk, 47.1%; P = .036) datasets. The online predictive model was made available at https://ktsahara.shinyapps.io/stageI_icc/. CONCLUSIONS: Patients with stage I ICC without vascular invasion or lymph node metastasis had a relatively high incidence of recurrence. An online tool can risk stratify patients relative to recurrence risk to identify individuals best suited for alternative treatment approaches.