Overall Tumor Burden Dictates Outcomes for Patients Undergoing Resection of Multinodular Hepatocellular Carcinoma Beyond the Milan Criteria.

OBJECTIVE: The objective of the current study was to define surgical outcomes after resection of multinodular hepatocellular carcinoma (HCC) beyond the Milan criteria, and develop a prediction tool to identify which patients likely benefit the most from resection. BACKGROUND: Liver resection for multinodular HCC, especially beyond the Milan criteria, remains controversial. Rigorous selection of the best candidates for resection is essential to achieve optimal outcomes after liver resection of advanced tumors. METHODS: Patients who underwent resection for HCC between 2000 and 2017 were identified from an international multi-institutional database. Patients were categorized according to Milan criteria status. Pre- and postoperative overall survival (OS) prediction models that included HCC tumor burden score (TBS) among patients with multinodular HCC beyond Milan criteria were developed and validated. RESULTS: Among 1037 patients who underwent resection for HCC, 164 (15.8%) had multinodular HCC beyond the Milan criteria. Among patients with multinodular HCC, 25 (15.2%) patients experienced a serious complication and 90-day mortality was 3.7% (n = 6). Five-year OS after resection of multinodular HCC beyond Milan criteria was 52.8%. A preoperative TBS-based model (5-year OS: low-risk, 73.7% vs intermediate-risk, 45.1% vs high-risk, 13.1%), and postoperative TBS-based model (5-year OS: low-risk, 80.1% vs intermediate-risk, 37.2% vs high-risk, not reached) categorized patients into distinct prognostic groups relative to long-term prognosis (both P < 0.001). Pre- and postoperative models could accurately stratify OS in an external validation cohort (5-year OS; low vs medium vs high risk; pre: 66.3% vs 25.2% vs not reached, P = 0.012; post: 61.4% vs 42.5% vs not reached, P = 0.045) Predictive accuracy of the pre- and postoperative models was good in the training (c-index; pre: 0.68; post: 0.71), internal validation (n = 2000 resamples) (c-index, pre: 0.70; post: 0.72) and external validation (c-index, pre: 0.67; post 0.68) datasets. TBS alone could stratify patients relative to 5-year OS after resection of multinodular HCC beyond Milan criteria (c-index: 0.65; 5-year OS; low TBS: 70.2% vs medium TBS: 54.7% vs high TBS: 16.7%; P < 0.001). The vast majority of patients with low and intermediate TBS were deemed low or medium risk based on both the preoperative (98.4%) and postoperative risk scores (95.3%). CONCLUSION: Prognosis of patients with multinodular HCC was largely dependent on overall tumor burden. Liver resection should be considered among patients with multinodular HCC beyond the Milan criteria who have a low- or intermediate-TBS.

Oxidative DNA damage correlates with cell immortalization and mir-92 expression in hepatocellular carcinoma.

BACKGROUND: MicroRNAs expression has been extensively studied in hepatocellular carcinoma but little is known regarding the relationship, if any, with inflammation, production of reactive oxygen species (ROS), host's repair mechanisms and cell immortalization. This study aimed at assessing the extent of oxidative DNA damage (8-hydroxydeoxyguanosine - 8-OHdG) in different phases of the carcinogenetic process, in relation to DNA repair gene polymorphism, telomeric dysfunction and to the expression of several microRNAs, non-coding genes involved in post-transcriptional regulation, cell proliferation, differentiation and death. METHODS: Tissue samples obtained either at surgery, [neoplastic (HCC) and adjacent non-cancerous cirrhotic tissues (NCCT)] at percutaneous or laparoscopic biopsy (patients with HCV or HBV-related hepatitis or patients undergoing cholecystectomy) were analysed for 8-OHdG (HPLC-ED), OGG1 (a DNA repair gene) polymorphism (PCR-RFLP), telomerase activity, telomere length (T/S, by RT-PCR), Taqman microRNA assay and Bad/Bax mRNA (RT-PCR). Fifty-eight samples from 29 HCC patients (obtained in both neoplastic and peritumoral tissues), 22 from chronic hepatitis (CH) and 10 controls (cholecystectomy patients - CON) were examined. RESULTS: Eight-OHdG levels were significantly higher in HCC and NCCT than in CH and CON (p=0.001). Telomerase activity was significantly higher in HCC than in the remaining subgroups (p=0.002); conversely T/S was significantly lower in HCC (p=0.05). MiR-199a-b, -195, -122, -92a and -145 were down-regulated in the majority of HCCs while miR-222 was up-regulated. A positive correlation was observed among 8-OHdG levels, disease stage, telomerase activity, OGG1 polymorphisms and ALT/GGT levels. In HCC, miR-92 expression correlated positively with telomerase activity, 8-OHdG levels and Bad/Bax mRNA. CONCLUSIONS: The above findings confirm the accumulation, in the progression of chronic liver damage to HCC, of a ROS-mediated oxidative DNA damage, and suggest that this correlates with induction of telomerase activity and, as a novel finding, with over-expression of miR-92, a microRNA that plays a role in both the apoptotic process and in cellular proliferation pathways.