Conditional survival after radiofrequency ablation for early-stage hepatocellular carcinoma

We analyzed how conditional survival (CS) after radiofrequency ablation (RFA) for early-stage hepatocellular carcinoma (HCC) predicts survival estimates over time. We enrolled 791 patients with newly diagnosed early-stage HCC (i.e., within Milan criteria) and Child-Pugh class A liver disease undergoing RFA. Three-year CS, calculated as CS = S(x + 3)/S(x), was the probability of surviving an additional three years, given that the patient had already survived x years. One-, three-, and five-year overall survival rates were 96.3, 72.3, and 59.7%, respectively, and were lower for patients with a MELD score of > 9, BCLC stage A disease, and AFP level of ≥ 20 ng/ml. However, three-year CS showed that patients ablated for BCLC stage A or AFP ≥ 20 ng/ml had the same survival probabilities as patients with BCLC stage 0 or AFP < 20 ng/ml from the third year onward after RFA. In contrast, the three-year CS of patients with a MELD score of ≤ 9 was always better than that of patients with a MELD score of > 9. We concluded that CS showed that the impact of different variables on survival after RFA is not linear over time. Information derived from CS can be used to dynamically predict the prognosis of patients with HCC.