Objective: To investigate the prognostic factors affecting outcome in Radiofrequency (RF) ablation of primary hepatic tumors by univariate and multivariate analyses, and to assess the therapeutic efficacy of Radio-frequency ablation.
Methods: A total of 172 patients with primary hepatic tumors underwent RF treatment in our department between 1999 and 2004. Among them, 150 patients were not the surgery candidates. The follow-up period ranged from 4 to 51 months and follow-up rate was 94.8% (163 patients). Kaplan-Meier model and log-rank test were used in univariate analyses and COX regression model was used in multivariate analyses, to identify prognostic factors for survival.
Results: The survival rates at half a year, 1 year, 2 year and 3 year were 91.5%, 77.4%, 55.7% and 51.2% respectively. Using univariate analyses, 24 potential factors were analyzed and 8 of them were found significant for survival. These 8 factors were Child-Pugh grade, UICC stage, AFP value before first RF, Portal hypertension, first treatment or treatment for recurrence, pathological grade, treatment purpose and method, ablative safe margin. For 116 patients who underwent RF when first diagnosis, the survival rates in patients with different tumor stage (UICC standard of hepatocellular carcinoma) at half a year, 1 year, 2 year and 3 year were estimated as follows: 96.7%, 92.3%, 81.6% and 65.3% in 33 patients of stage I-II; 91.2%, 76.3%, 56.6% and 51.4% in 83 patients of stage III-IV; There was significant difference in survival rates between patients of stage I-II and patients of stage III-IV. For 56 patients suffered from recurrent hepatic tumors, the survival rates at half a year, 1 year, 2 year and 3 year were 88.5%, 70.2%, 41.4% and 24.5%, being similar to those of stage III-IV. The 8 factors mentioned above were further analyzed by multivariate model and 3 of them were identified as prognostic factors for survival. These 3 factors included Child-Pugh grade, Portal hypertension, treatment purpose and method.
Conclusion: Based on our statistical analysis, the prognostic factors on outcome in Radio-frequency ablation of hepatic tumors were grouped into two categories. Child-Pugh grade, and Portal hypertension were the characteristics of patients and uncontrollable. While treatment purpose and method also had significant impact on survival and was controllable during RF procedure. This information might be useful to improve treatment level of Radio-frequency ablation of hepatic tumors.