Local treatment including RT for HCC with portal invasion: a matched analysis using nationwide data

초록

Purpose or Objective Local treatment including radiotherapy (LRT) has been applied as an effective palliation for hepatocellular carcinoma (HCC) with portal invasion, although survival benefit has been clearly established. We aimed to identify oncologic benefit of LRT as compared to best supportive care (BSC), and difference of benefit according to categorized hepatic reserve using Child-Pugh class (CPC) and ALBI (Albumin-Bilirubin) grades. Materials and Methods Patients diagnosed with HCC invading portal vein and extracted in Korean Central Cancer Registration (KCCR) between 2008 to 2014 were included and classified into LRT group and BSC group. 1:1 Propensity matching was performed to reduce selection bias and effect of potential confounders. Results A total of 1,163 patients were analyzed. The LRT group was significantly younger than BSC group (p <0.001). The mean Child-Pugh score of LRT group was 6.1, which was significantly lower than 7.7 of BSC group (p<0.001). The 51.9% of LRT group had single HCC, significantly different from 39.3% of BSC group (p=0.001). Extrahepatic metastases (EHM) were less prevalent in LRT group than BSC group (23.45 vs. 31.3%, p=0.023). The 1:1 PS-matched analysis generated 222 pairs, and all clinical characteristics were comparable between PS-matched groups. Median survival of all patients, LRT, and BSC groups were 5.0, 8.0 and 2.0 months, respectively. One year overall survival rates in LRT and BSC groups were 34.2% and 16.2%, and 12.6% and 6.8% at two years, respectively (p <0.001). Multivariate analysis showed that LRT (hazard ratio 0.41, 95% CI 0.32-0.52), age of >60 years, presence of EHM, main tumor size of ≥10cm, and CPC B or C were independent predictors for higher mortality in patients with HCC invading portal vein (all p <0.05). In subgroup analysis according to the CPC-ALBI class, the statistical differences in survival were maintained in all CPC-ALBI class (all p <0.05). Conclusion LRT demonstrated significant benefit regarding OS and CSS. The benefit is valid for CPC A as well as CPC B patients. Our result has a significance of representing community-level data from all administrative districts in Korea. The difference in LRT benefit according to subclassified hepatic reserve should be investigated in future studies.