Pre-procedure Prognostic Factors to Predict Survival of Patients after Radiofrequency Ablation of Hepatocellular Carcinoma

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WSW Chan, SS Chiu, DHY Cho, SK Kei, WL Poon, SH Luk, CC Cheung

Hong Kong J Radiol 2010;13:3-11

Objective: This study evaluated the clinical, biochemical, and imaging characteristics to identify pre-ablative prognostic factors for the survival of patients undergoing radiofrequency ablation of hepatocellular carcinoma. Radiofrequency ablation has now been adopted as a curative management for small hepatocellular carcinomas, particularly in patients not suitable for surgery. Studies have shown that it confers comparable patient survival to surgical excision for small tumours with adequate ablation margins. However, we wished to evaluate preradiofrequency ablation factors prognostic for survival, so as to guide our management with a combination of treatment modalities.

Methods: A total of 68 consecutive patients having radiofrequency ablation for hepatic tumours from July 2004 to July 2008 were recruited. From among these 68 patients, the findings of 51 patients (with 75 hepatocelluar carcinomas) were analysed. Overall cumulative survival and recurrence-free survival were estimated using the Kaplan-Meier method. To evaluate significant prognostic factors for survival analysis, clinical factors including patient age, Child-Pugh status, biochemical factors including alpha-fetoprotein level, findings from imaging including maximal tumour size, tumour multiplicity (solitary versus multiple nodules) were subjected to univariate and multivariate Cox regression.

Results: The mean age of patients was 63 (standard deviation, 12) years. Of 51 patients, 43 (84%) received percutaneous radiofrequency ablation. The mean tumour size was 2.5 (standard deviation, 0.96) cm. Mean alphafetoprotein levels at the time of hepatocellular carcinoma diagnosis was 563 (standard deviation, 1834) ng/ml. Patients were followed up for a median period of 509 (range, 3-1350) days. The mean follow-up time was 520 (standard deviation, 330) days. Overall recurrence including both intrahepatic (distant) and local progression ensued in 23 patients (44%). Twenty-one patients (41%) died during the follow-up period. The estimated median overall cumulative survival was 1000 (95% confidence interval, 564-1435) days. The overall estimated 6-, 12-, 18-, and 24-month survival rates were 84%, 73%, 66%, and 58% respectively. Tumour multiplicity was found to be a significant prognostic factor for overall survival (adjusted hazard ratio = 5.31; 95% confidence interval, 2.02-14.00; p = 0.001) and recurrence-free survival (2.69; 1.12-6.46; 0.026).

Conclusion: After radiofrequency ablation, tumour multiplicity was found to be a significant prognostic factor for predicting overall and recurrence-free survival in these patients.





目的:本研究評估接受射頻消融術治療肝腫瘤患者的臨床、生化及影像特性,從中識別預測患者存 活率的術前因素。射頻消融術已成為治療小肝癌的一種方法,尤其是對於不適合手術的病人。有研 究指出,只要小腫瘤有足夠消融範圍,此技術的病人存活率跟切除術相若。縱使如此,我們仍然希 望評估預測存活率的術前因素,以便為結合不同治療方案的做法作一指引。

方法:收集2004年7月至2008年7月期間,所有68位接受射頻消融術治療肝腫瘤的病人資料,分析 其中51人(共75個肝腫瘤)的結果。運用Kaplan-Meier方法估計病人的整體累積存活率及無復發存 活率。並用單元及多元Cox回歸分析評估預測存活率的有效預測因素,包括臨床因素如病人年齡、 Child-Pugh肝功能分級、生化因素如甲胎蛋白水平、以及影像結果如腫瘤最大體積、腫瘤多發性(孤 立或多發結節)。

結果:病人平均年齡63歲(標準差12歲)。51位病人中,43位(84%)接受經皮射頻消融術。腫瘤 平均大小為2.5 cm(標準差0.96 cm),確診時平均甲胎蛋白水平563 ng/ml(標準差1834 ng/ml)。隨 訪期中位數509天(介乎3至1350天),平均520天(標準差330天)。包括肝內遠處轉移及局部原位 復發在內,共計23位(44%)病人出現復發。隨訪期間有21位病人(41%)死亡。整體累積存活率 的中位數估計為1000天(95%置信區間:564至1435天)。6、12、18及24個月的存活率分別估計為 84%、73%、66%及58%。腫瘤多發性是整體存活率(調整後的危險比率5.31;95%置信區間:2.02至 14.00;p = 0.001)及無復發存活率(調整後的危險比率2.69;95%置信區間1.12至6.46;p = 0.026)的 一項有效預測因素。