Spontaneous regression of hepatocellular carcinoma: a systematic review.

ABSTRACT

OBJECTIVE: To estimate the actual frequency of spontaneous regression of hepatocellular carcinoma. METHODS: A systematic review of the literature published during 1978-2007 has been carried out to identify randomized clinical trials of hepatocellular carcinoma that included a control arm receiving either placebo or best supportive care, and in which patients were followed prospectively for tumor response using predefined criteria. Data extraction was conducted independently by two investigators. A meta-analysis to provide a global estimation of regressions in the control arms was performed using an empiric Bayesian random-effects model. RESULTS: We identified 16 cases of regression (including minor and partial responses) in 10 phase III clinical trials. The rate of spontaneous objective partial regression among patients with hepatocellular carcinoma was 0.406% [95% confidence interval 0.067-1.043%]. CONCLUSION: Although very infrequent, spontaneous regression is not an extraordinary event among patients with hepatocellular carcinoma. Therefore, individual responses to any given therapy should be assessed with caution and this fact may be considered at the time of calculating sample size of pilot clinical trials of new agents.