Clinical features and prognosis in patients with hepatocellular carcinoma that developed after hepatitis C virus eradication with interferon therapy

Hepatitis C virus eradication prolongs overall survival in hepatocellular carcinoma patients receiving molecular-targeted agents

BACKGROUND

The aim of this multicenter retrospective study was to evaluate the impact of the eradication of hepatitis C virus (HCV) on the clinical outcomes of patients with hepatocellular carcinoma (HCC) treated with molecular-targeted agents (MTAs).

METHODS

Among 877 patients who received any MTA as first-line systemic therapy for HCC between June 2009 and March 2019, 569 patients with HCV-related HCC were enrolled in this retrospective study. Of these, 109 patients achieved sustained virological response (SVR) before starting MTA. After propensity score matching, the clinical outcomes of 109 patients in the SVR group and 109 patients in the non-SVR group were compared.

RESULTS

The median time to progression in the SVR group (7.8 months) was similar to that in the non-SVR group (5.6 months) (p = 0.212). The median time to treatment failure in the SVR group (5.3 months) was longer than that in the non-SVR group (2.8 months) (p = 0.059), and post-progression survival and overall survival in the SVR group were significantly longer than those in the non-SVR group (12.0 months vs 7.2 months; p = 0.039, and 18.1 months vs 11.3 months; p = 0.019). At the end of first-line MTA therapy, the albumin-bilirubin (ALBI) score in the SVR group ( - 2.25) was significantly lower than that in the non-SVR group ( - 2.10) (p = 0.008).

CONCLUSIONS

The eradication of HCV before MTA therapy maintained liver function and led to a prolonged treatment period and improved overall survival of HCV-related HCC patients. We should not overlook the benefits of HCV eradication in HCC patients.

Timing of DAA Initiation After Curative Treatment and Its Relationship with the Recurrence of HCV-Related HCC

Hepatitis C virus infection is a major cause of chronic hepatitis, leading to cirrhosis and hepatocellular carcinoma (HCC). Many studies agree that interferon (IFN)-based antiviral therapy can reduce the risk of HCC recurrence in patients with chronic hepatitis C who have achieved a sustained virological response (SVR). The recent introduction of direct-acting antivirals (DAA) has resulted in excitingly high SVR rates. However, as an IFN-free regimen, DAAs only exert antiviral activity without an immune response. The benefit of DAA-based regimens for HCC recurrence in patients with cirrhosis and following successful curative treatment remains controversial. Additionally, the time span between curative-intent therapy and the DAA regimen is an independent risk factor for HCC recurrence, irrespective of the DAA response. HCC patients who are eligible for potentially curative therapy by liver resection or ablation should defer DAA therapy; however, the accurate timing remains unclear. In this study, we reviewed the timing of DAA initiation after curative treatment and its effect on the recurrence of related HCC.

Clinical characteristics and prognosis of HCC occurrence after antiviral therapy for HCV patients between sustained and non-sustained responders

BACKGROUND

Hepatitis C virus (HCV)-infected patients who achieved sustained virologic response (SVR) may still develop hepatocellular carcinoma (HCC). The characteristic of HCC and the prognosis between SVR and non-SVR patients were not well known.

METHODS

Among 1884 HCV-infected patients who were treated with pegylated IFN plus ribavirin therapies, 122 patients developed HCC during follow-up were enrolled in this study. Laboratory data were collected before and at least 1 year after IFN-based therapy, as well as the latest follow-up.

RESULTS

Both SVR and non-SVR patients had similar risk factors to develop HCC, but with a little difference. Liver cirrhosis plays a key role in HCC occurrence in both groups. Among the patients who developed HCC, non-SVR patients had significantly higher total bilirubin, higher FIB-4, lower pre-treatment platelet count, higher pre-treatment AFP levels and higher proportion of cirrhosis than SVR patients before occurrence of HCC. After curative treatment, SVR patients had lower recurrence and longer overall survival than non-SVR patients by Kaplan-Meier analysis. Multivariate analysis revealed that APRI ≥0.7 was the independent risk factor for HCC recurrence; and AFP ≥20 ng/ml post IFN therapy, as well as HCC recurrence were the independent risk factors of mortality.

CONCLUSION

Liver cirrhosis plays a key role in HCC occurrence after antiviral therapies. SVR patients may have lower HCC recurrence and longer survival rates than non-SVR patients. Only APRI was associated with HCC recurrence; and post-IFN AFP and HCC recurrence were predictive of subsequent mortality independently.

Shear wave elastography predicts hepatocellular carcinoma risk in hepatitis C patients after sustained virological response

AIM

To evaluate the relationship between fibrosis and HCC after sustained virological response (SVR) to treatment for chronic hepatitis C (HCV).

METHODS

This single-center study retrospectively evaluated 196 patients who achieved SVR after HCV infection. The associations of risk factors with HCC development after HCV eradication were evaluated using univariate and multivariate Cox proportional hazards regression models.

RESULTS

Among the 196 patients, 8 patients (4.1%) developed HCC after SVR during a median follow-up of 26 months. Multivariate analyses revealed that HCC development was independently associated with age of ≥75 years (risk ratio [RR] = 35.16), α- fetoprotein levels of ≥6 ng/mL (RR = 40.30), and SWE results of ≥11 kPa (RR = 28.71).

CONCLUSIONS

Our findings indicate that SWE may facilitate HCC surveillance after SVR and the identification of patients who have an increased risk of HCC after HCV clearance.

Does interferon-free direct-acting antiviral therapy for hepatitis C after curative treatment for hepatocellular carcinoma lead to unexpected recurrences of HCC? A multicenter study by the Japanese Red Cross Hospital Liver Study Group

BACKGROUND AND AIM

This study aimed to elucidate whether interferon (IFN)-free direct-acting antiviral (DAA) therapy for hepatitis C after curative treatment of hepatocellular carcinoma (HCC) promotes HCC recurrence in a real-world large-scale cohort.

METHODS

This multicenter study was conducted by the Japanese Red Cross Hospital Liver Study Group. This retrospective study analyzed 516 patients who underwent antiviral treatment for hepatitis C with either IFN (n = 148) or IFN-free DAA (n = 368) after curative HCC treatment; 78 IFN-treated patients and 347 IFN-free DAA-treated patients achieved sustained virological response (SVR). The recurrence rate of HCC was compared between the antiviral therapies. Logistic analysis and Cox proportional hazards analysis identified factors associated with early recurrence of HCC within 24 weeks of antiviral therapy and recurrence throughout the observation period, respectively.

RESULTS

AFP at the completion of antiviral therapy, clinical stage of HCC, and non-SVR were independent factors associated with early recurrence of HCC. Among patients who had achieved SVR, the clinical stage of HCC and the level of AFP at completion of antiviral therapy were independent factors associated with early recurrence of HCC. For recurrence throughout the observation period in SVR patients, AFP at completion of antiviral therapy, duration between last HCC treatment to antiviral therapy, and the number of treatments were independent factors. There was no significant difference in the rate of early recurrence of HCC or recurrence throughout the observation period between IFN and IFN-free DAA treated patients.

CONCLUSIONS

There were no differences in the early recurrence rate of HCC between patients who underwent IFN and those who underwent IFN-free DAA as antiviral therapies.

Treatment of Elderly Patients with Chronic Hepatitis C: A Retrospective Cohort Study

SUMMARY – The prevalence of chronic hepatitis C increases in elderly patients. The aims of this study were to identify the factors associated with hepatocellular carcinoma (HCC) and end-stage liver disease development and to evaluate the efficacy and safety of pegylated interferon (PEG-IFNα) plus ribavirin (RBV) therapy in elderly patients. A retrospective cohort study included all consecutive patients with hepatitis C virus (HCV) infection treated with PEG-IFNα+RBV between 2003 and 2013. Elderly patients had a higher frequency of poor prognostic factors including genotype 1 infection, high fibrosis, and high fibrosis index based on four factors (FIB-4) score. The sustained virologic response (SVR) rate for genotype 1 was significantly lower (35.8% vs. 57.1%), while the frequency of PEG-IFNα (27.2% vs. 7.8%), RBV dose reduction (19.6% vs. 9.7%) and treatment discontinuation (13.0% vs. 4.1%) was significantly higher in elderly patients. However, age was not associated with SVR in multivariate analysis, and comparable SVR rates were achieved when adjusted for fibrosis score (Ishak ≤3: 66.7% vs. 69.8%). During the follow-up, HCC was diagnosed in 18 elderly patients (3 SVR+, 4 SVR- and 9 untreated patients). In conclusion, selected elderly patients can achieve comparable SVR rates as younger patients, but with a higher rate of side effects. Since complications of HCV infection occur more frequently in elderly patients, they should be given priority for antiviral therapy.

Clinical Model for Predicting Hepatocellular Carcinomas in Patients with Post-Sustained Virologic Responses of Chronic Hepatitis C: A Case Control Study

Background/Aims

No clinical model exists to predict the occurrence of hepatocellular carcinoma in sustained virologic response-achieving (HCC after SVR) patients with chronic hepatitis C (CHC).

Methods

We performed a case-control study using a clinical database to research the risk factors for HCC after SVR. A predictive model based on risk factors was established, and the area under the receiver operating characteristic curve (AUC) was calculated.

Results

In the multivariate model, an initial diagnosis of compensated cirrhosis and post-SVR albumin reductions of 1 g/L were associated with 21.7-fold (95% CI, 4.2 to 112.3; p<0.001) and 1.3-fold (95% CI, 1.1 to 1.7; p=0.004) increases in the risk of HCC after SVR, respectively. A predictive model based on an initial diagnosis of compensated cirrhosis (yes, +1; no, 0) and post-SVR albumin ≤36.0 g/L (yes, +1; not, 0) predicted the occurrence of HCC after SVR with a cutoff value of >0, an AUC of 0.880, a sensitivity of 0.833, a specificity of 0.896, and a negative predictive value of 0.956.

Conclusions

An initial diagnosis of compensated cirrhosis combined with a post-SVR albumin value of ≤36.0 g/L predicts the occurrence of HCC after SVR in patients with CHC.

Antiproliferative effect of ME3738, a derivative of soyasapogenol, on hepatocellular carcinoma cell lines in vitro and in vivo

Soyasapogenol, an aglycon of soyasaponin, ameliorates liver injury induced by concanavalin A in mice. A derivative of soyasapogenol, 22β-methoxyolean-12-ene-3β, 24(4β)-diol (ME3738), was reported to induce the gene expression of interferon (IFN)-β in hepatitis C virus replicon cells. The effect of ME3738 on hepatocellular carcinoma (HCC) cell lines was investigated in the present study. A total of 11 HCC cell lines were cultured in medium containing 0-10 µM ME3738, and after 24, 48, or 72 h of culture, morphological observation and MTT cell growth assays were performed. Furthermore, the effects of ME3738 with or without PEG-IFN-α-2b on cell lines were investigated. Induction of apoptosis was examined on cells treated with 1 µM of ME3738 using an Annexin V assay. The effect of ME3738 (0.63 and 2.5 µM) on cell cycle progression was analyzed on two cell lines. The mice with subcutaneous tumors were divided into four groups: i) Control; ii) ME3738 alone; iii) PEG-IFN-α-2b alone and iv) ME3738+PEG-IFN-α-2b (combination). ME3738 was mixed with food (1.5 mg/g) and was taken orally for 15 days. PEG-IFN-α-2b (1,920 IU/mouse) was subcutaneously injected twice a week for two consecutive weeks. On day 15, the mice were sacrificed and the tumors were resected. A dose-dependent anti-proliferative effect was observed to various degrees in all the HCC cell lines in vitro. This inhibitory effect reached its maximal level 24 h after the treatment and the 50% inhibitory dose was between 0.8 and 2.4 µM. The combination treatment did not show a synergistic effect. Induction of apoptosis was not observed. Cell cycle arrest at S-phase was observed in two of the examined cell lines. On day 15, the tumor volume of mice receiving ME3738, PEG-IFN-α-2b, and ME3738+PEG-IFN-α-2b was 69, 30, and 33%, respectively, of the control tumor volume. ME3738 induced antiproliferative effects on the HCC cells in vitro and in vivo. The data suggested potential clinical application of ME3738.

Development of hepatocellular carcinoma in patients with hepatitis C virus infection who achieved sustained virological response following interferon therapy: A large-scale, long-term cohort study

BACKGROUND

We assessed the risk factors for the development of hepatocellular carcinoma (HCC) following successful eradication of hepatitis C virus (HCV) with interferon (IFN) therapy in a long-term, large-scale cohort study.

METHODS

We reviewed 1094 consecutive patients with HCV who achieved sustained virological response (SVR) following IFN therapy between January 1995 and September 2013.

RESULTS

During the observation period (median 50 months: range 13-224), 36 (3%) of 1094 patients developed HCC after SVR. The median period from SVR to diagnosis of HCC was 37 months (range 17-141), and the cumulative rates of HCC at 5, 10, and 15 years were 4%, 6%, and 12%, respectively. Multivariate analysis identified old age (≥60 years, HR, 3.1: 95%CI, 1.3-6.6: P = 0.009), male sex (HR, 12.0: 95%CI, 2.8-50.0: P < 0.0001), advanced fibrosis stage (F3/4, HR, 3.2: 95%CI, 1.6-7.2: P < 0.0001), and alpha-fetoprotein ≥10 ng/mL at 1 year after SVR (HR, 7.8: 95%CI, 2.9-16.8: P < 0.0001) as significant and independent risk factors for post-SVR HCC.

CONCLUSIONS

Older age and male sex (host factors), advanced fibrosis stage (pre-IFN treatment factor), and higher alpha-fetoprotein values (post-treatment factor) were significantly associated with HCC development after HCV eradication.

Effects of antiviral therapy for hepatitis C following treatment of hepatocellular carcinoma: survey findings of the Japanese Red Cross Liver Study Group

AIM

To investigate, in a large number of cases at multiple institutions, the effects and limitations of antiviral therapy for hepatitis C following treatment of hepatocellular carcinoma (HCC) in clinical practice.

METHODS

Retrospective analysis was performed of 112 patients who had received interferon (IFN) for treating hepatitis C following treatment of HCC and were registered with the Japanese Red Cross Liver Study Group. Factors that may influence recurrence and survival rates were investigated.

RESULTS

Factors involved in prevention of recurrence were: surgical resection as HCC treatment, platelet and α-fetoprotein (AFP) levels prior to IFN administration, IFN adherence and post-IFN AFP level. Multivariate analysis showed post-IFN AFP level to be an independent factor. Factors involved in prolonging survival were: IFN adherence, IFN response (sustained viral response), pre-IFN alanine aminotransferase and AFP levels, post-IFN AFP level and absence of recurrence. Multivariate analysis showed absence of recurrence to be an independent factor. Although IFN adherence was involved in recurrence and survival, ribavirin adherence was not. IFN was suggested to be involved in preventing recurrence and improving survival due not only to its anti-viral effect, but also its antitumor effect.

CONCLUSION

Although complete prevention of HCC recurrence is difficult, the most important factor affecting first recurrence is the AFP level at 6 months after the conclusion of antiviral treatment. The survival rate improves dramatically if the hepatitis C virus is eliminated, but the most important factor for improving survival is absence of recurrence.

Long-Term Outcomes of Hepatitis-C-Infected Patients Achieving a Sustained Virological Response and Undergoing Radical Treatment for Hepatocellular Carcinoma

<b><i>Background and Aims:</i></b> A sustained virological response (SVR) decreases the incidence of hepatocellular carcinoma (HCC) in patients with hepatitis C. We investigated the long-term outcomes of patients who developed HCC after achieving SVR with interferon therapy. <b><i>Patients:</i></b> Of 75 patients who developed HCC after SVR, 40 patients underwent radical therapies (SVR group). From 436 patients undergoing surgical resection for hepatitis C virus-positive HCC, 80 patients were randomly chosen as a control cohort, after adjusting for age, gender, and extent of hepatic fibrosis (non-SVR group). Patients were observed for a median of 5.08 years. <b><i>Results:</i></b> HCC recurrence was found in 16 SVR patients and in 66 non-SVR patients. The respective HCC recurrence rates of SVR and non-SVR patients were 23 and 56% at 3 years, 42 and 77% at 5 years, and 53 and 90% at 10 years (p = 0.001). The respective overall survival rates in the SVR and non-SVR groups were 93 and 68% at 5 years, 88 and 34% at 10 years, and 53 and 21% at 15 years (p<i> = </i>0.001). <b><i>Conclusion:</i></b> Although SVR patients had a significantly lower HCC recurrence rate than the non-SVR patients, the cumulative recurrence rate of SVR patients increased to 86% at 15 years.

Alcoholic liver disease: Clinical and translational research

The present review spans a broad spectrum of topics dealing with alcoholic liver disease (ALD), including clinical research, translational research, pathogenesis and therapies. A special accent is placed on alcohol misuse, as alcohol is a legally commercialized and taxable product. Drinking alcohol, particularly from a young age, is a major health problem. Alcoholism is known to contribute to morbidity and mortality. A systematic literature search was performed in order to obtain updated data (2008-2015). The review is focused on genetic polymorphisms of alcohol metabolizing enzymes and the role of cytochrome p450 2E1 and iron in ALD. Alcohol-mediated hepatocarcinogenesis is also discussed in the presence or absence of co-morbidities such as viral hepatitis C as well as therapeutic the role of innate immunity in ALD-HCV. Moreover, emphasis was placed on alcohol and drug interactions, as well as liver transplantation for end-stage ALD. Finally, the time came to eradicate alcohol-induced liver and intestinal damage by using betaine.

Serum Alpha-Fetoprotein Has High Specificity for the Early Detection of Hepatocellular Carcinoma After Hepatitis C Virus Eradication in Patients

Alpha-fetoprotein (AFP) has not played a large role in the surveillance of hepatocellular carcinoma due to inadequate sensitivity and specificity for active chronic hepatitis or cirrhosis. The aim of this study was to evaluate the diagnostic accuracy of AFP in small hepatocellular carcinomas after hepatitis C virus eradication to determine the optimal cutoff value. We conducted a case-control study of 29 cases and 58 controls, matched for age, gender, and platelet counts. The AFP cutoff was 5 ng/mL in patients after hepatitis C virus eradication and 17 ng/mL in those without hepatitis C virus eradication. The areas under the receiver operating characteristic curve were 0.86 (95% confidence interval, 0.76-0.96) in patients after hepatitis C virus eradication and 0.83 (95% confidence interval, 0.74-0.91) in those without hepatitis C virus eradication. In patients after hepatitis C virus eradication, the sensitivity and specificity of AFP levels were 24.1% and 100%, respectively, using a cutoff value of 17 ng/mL. Using a lower cutoff value of 5 ng/mL, the sensitivity increased to 75.9%, although the specificity decreased to 89.0%. AFP is a specific tumor marker for the diagnosis of hepatocellular carcinoma after hepatitis C virus eradication when using the optimal cutoff value of 5 ng/mL.

Oncogenic viruses and hepatocellular carcinoma

About 80% of hepatocellular carcinoma (HCC) is caused by hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections especially in the setting of established cirrhosis or advanced fibrosis, making HCC prevention a major goal of antiviral therapy. HCC tumors are highly complex and heterogeneous resulting from the aberrant function of multiple molecular pathways. The roles of HCV or HBV in promoting HCC development are still either directly or indirectly are still speculative, but the evidence for both effects is compelling. In patients with chronic hepatitis viral infection, cirrhosis is not a prerequisite for tumorigenesis.

Prognostic roles of preoperative α-fetoprotein and des-γ-carboxy prothrombin in hepatocellular carcinoma patients

AIM: To clarify the utility of using des-γ-carboxy prothrombin (DCP) and α-fetoprotein (AFP) levels to predict the prognosis of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV) and the hepatitis C virus (HCV) infections.

METHODS: A total of 205 patients with HCC (105 patients with HBV infection 100 patients with HCV infection) who underwent primary hepatectomy between January 2004 and May 2012 were enrolled retrospectively. Preoperative AFP and DCP levels were used to create interactive dot diagrams to predict recurrence within 2 years after hepatectomy, and cutoff levels were calculated. Patients in the HBV and HCV groups were classified into three groups: a group with low AFP and DCP levels (LL group), a group in which one of the two parameters was high and the other was low (HL group), and a group with high AFP and DCP levels (HH group). Liver function parameters, the postoperative recurrence-free survival rate, and postoperative overall survival were compared between groups. The survival curves were compared by log-rank test using the Kaplan-Meier method. Multivariate analysis using a Cox forward stepwise logistic regression model was conducted for a prognosis.

RESULTS: The preoperative AFP cutoff levels for recurrence within 2 years after hepatectomy in the HBV and HCV groups were 529.8 ng/mL and 60 mAU/mL, respectively; for preoperative DCP levels, the cutoff levels were 21.0 ng/mL in the HBV group and 67 mAU/mL in the HCV group. The HBV group was significantly different from the other groups in terms of vascular invasion, major hepatectomy, volume of intraoperative blood loss, and surgical duration. Significant differences were found between the LL group, the HL group, and the HH group in terms of both mean disease-free survival time (MDFST) and mean overall survival time (MOST): 64.81 ± 7.47 vs 36.63 ± 7.62 vs 18.98 ± 6.17 mo (P = 0.001) and 85.30 ± 6.55 vs 59.44 ± 7.87 vs 46.57 ± 11.20 mo (P = 0.018). In contrast, the HCV group exhibited a significant difference in tumor size, vascular invasion, volume of intraoperative blood loss, and surgical duration; however, no significant difference was observed between the three groups in liver function parameters except for albumin levels. In the LL group, the HL group, and the HH group, the MDFST was 50.09 ± 5.90, 31.01 ± 7.21, and 14.81 ± 3.08 mo (log-rank test, P < 0.001), respectively, and the MOST was 79.45 ± 8.30, 58.82 ± 7.56, and 32.87 ± 6.31 mo (log-rank test, P < 0.001), respectively.

CONCLUSION: In the HBV group, the prognosis was poor when either AFP or DCP levels were high. In the HCV group, the prognosis was good when either or both levels were low; however, the prognosis was poor when both levels were high. High levels of both AFP and DCP were an independent risk factor associated with tumor recurrence in the HBV and HCV groups. The relationship between tumor marker levels and prognosis was characteristic to the type of viral hepatitis.

Suppression of hepatocellular carcinoma development in hepatitis C patients given interferon-based antiviral therapy

The advance of antiviral treatment for chronic hepatitis C has brought a high sustained virological response (SVR) rate. In this review article, the suppressive effect of interferon (IFN)-based therapy on the development of hepatocellular carcinoma (HCC), risk factors for developing HCC and the characteristics of HCC development after SVR among chronic hepatitis C patients given IFN-based therapy were studied. The HCC incidence has been revealed to decrease with IFN-based antiviral therapy, especially in SVR, and the risk factors for developing HCC were older age, advanced liver fibrosis and male sex. α-Fetoprotein levels at 24 weeks after the end of IFN-based treatment was associated strongly with HCC incidence irrespective of virological response. In patients with SVR, other risk factors were glucose metabolism disorders, lipid metabolism disorders and alcohol intake. Extra attention to the possibility of HCC incidence should be required for these SVR patients. Antiviral therapy with a combination of HCV-specific direct-acting antivirals (DAA) is expected to be utilized in the future. However, it is not known whether DAA-based treatment can suppress HCC to the level of IFN-based treatment. Further research is required to clarify this.

Clinical characteristics of patients who developed hepatocellular carcinoma after hepatitis C virus eradication with interferon therapy: current status in Japan

OBJECTIVE

We attempted to elucidate the clinical features of chronic hepatitis C patients who develop hepatocellular carcinoma (HCC) after achieving a sustained viral response (SVR) to interferon (IFN) therapy.

METHODS

The clinical features of 130 patients at 19 hospitals who developed HCC after obtaining an SVR were retrospectively reviewed.

RESULTS

Overall, 107 (82%) of the 130 patients were men, with 92 (71%) being ≥60 years of age and 76, 38 and 16 developing HCC within 5, 5-10 and 10-16.9 years after IFN therapy, respectively. Before receiving IFN therapy, 92 (71%) patients had cirrhosis and/or a low platelet count (<15×10(4) cells/μL). Lower albumin (<3.9 g/dL) and higher alpha fetoprotein (AFP) (≥10 ng/mL) levels were identified in a multivariate analysis to be independent variables of the development of HCC within five years after IFN therapy. Among 4,542 SVR patients, HCC occurred in 109 (2.4%) during a 5.5-year follow-up period, thus resulting in an occurrence rate of 4.6% for men and 0.6% for women.

CONCLUSION

SVR patients with lower albumin or higher AFP levels require careful assessments to prevent early HCC development after IFN therapy. HCC occurrence within >10 years of IFN therapy is not uncommon, and the risk factors remain uncertain, thus suggesting that all SVR patients should undergo long-term follow-up examinations for HCC development.