Redefining Conditional Overall and Disease-Free Survival After Curative Resection for Intrahepatic Cholangiocarcinoma: a Multi-institutional, International Study of 1221 patients

Objectives: To assess conditional survival (CS) according to recurrence status, as well as conditional disease-free survival (cDFS) among patients with intrahepatic cholangiocarcinoma (ICC). Methods: CS and cDFS were evaluated among ICC patients who underwent curative-intent resection for ICC by using a multi-institutional database. Five-year CS (CS5) at “x” years was calculated separately for patients who did and did not experience recurrence. The cDFS3 at “x” years was defined as the chance to be disease-free for an additional 3 years after not having experienced a recurrence for “x” years postoperatively. Results: Among 1221 patients, median OS was 36.8 months. While estimated actuarial OS decreased over time, CS5 increased as patients survived over longer periods of time and reached 93.9% at 4 years among 139 patients who did not experience a recurrence. Among the 725 (59.4%) patients who did experience a tumor recurrence, CS5 decreased to 17.7% the first postoperative year; however, CS5 subsequently increased to 79.7% for 81 patients who had survived 4 years after surgery. While actuarial DFS decreased from 54.6% at 1 year to 28.2% at 5 years, estimated cDFS3 following liver resection increased over time. Of note, patients with known risk factors for recurrence had even more marked improvements in cDFS3 over subsequent years versus patients without risk factors for recurrence. Conclusion: CS and cDFS changed over time according to the presence of disease-specific risk factors, as well as the presence of recurrence.