Cause-specific mortality associated with aging in patients with hepatocellular carcinoma undergoing percutaneous radiofrequency ablation.

Fujiwara, Naoto; Tateishi, Ryosuke; Kondo, Mayuko; Minami, Tatsuya; Mikami, Shintaro; Sato, Masaya; Uchino, Koji; Enooku, Kenichiro; Masuzaki, Ryota; Nakagawa, Hayato; Kondo, Yuji; Asaoka, Yoshinari; Shiina, Shuichiro; Yoshida, Haruhiko; Koike, Kazuhiko

OBJECTIVE The number of elderly patients diagnosed with hepatocellular carcinoma (HCC) is expected to increase. The aim of this study is to evaluate the efficacy of radiofrequency ablation (RFA) in elderly patients with HCC and to investigate cause-specific excess deaths associated with increasing number of elderly patients. MATERIALS AND METHODS We enrolled 1401 naive patients with HCC who were treated initially by RFA from 1999 to 2011. Patients below 75 years of age were categorized as 'younger' and those at least 75 as 'elderly'. Differences in the demographic and laboratory data of these patients were assessed, along with Kaplan-Meier analysis of survival using the log-rank test. In addition, we assessed the causes of death, defined as liver related and liver unrelated, by competing risk analysis and risk factors for respective causes of death by a proportional subdistribution model. RESULTS Overall, 353 patients were categorized as elderly. Elderly patients were more likely to be women, infected with hepatitis C virus, and score better in the Child-Pugh classification. The mortality at 5 years was lower in the elderly than in the younger patients (47.3 vs. 37.1%; P<0.001). Competing risk analysis showed a significant difference in liver-unrelated death (P<0.001) between the two groups, whereas there were no significant differences in liver-related death (P=0.64). By the proportional subdistribution model, age was a significant risk factor only for liver-unrelated death. CONCLUSION RFA provided satisfactory 5-year survival rates in elderly patients with HCC. The elderly tended to die from liver-unrelated causes.