Methodological challenges of performing meta-analyses to compare the risk of hepatocellular carcinoma between chronic hepatitis B treatments

Entecavir versus tenofovir on the recurrence of hepatitis B-related HCC after liver transplantation: A multicenter observational study

Considerable controversy exists regarding the superiority of tenofovir disoproxil fumarate (TDF) over entecavir (ETV) for reducing the risk of HCC. This study aimed to compare outcomes of ETV versus TDF after liver transplantation (LT) in patients with HBV-related HCC. We performed a multicenter observational study using data from the Korean Organ Transplantation Registry. A total of 845 patients who underwent LT for HBV-related HCC were divided into 2 groups according to oral nucleos(t)ide analogue used for HBV prophylaxis post-LT: ETV group (n = 393) and TDF group (n = 452). HCC recurrence and overall death were compared in naïve and propensity score (PS)-weighted populations, and the likelihood of these outcomes according to the use of ETV or TDF were analyzed with various Cox models. At 1, 3, and 5 years, the ETV and TDF groups had similar HCC recurrence-free survival (90.7%, 85.6%, and 84.1% vs. 90.9%, 84.6%, and 84.2%, respectively, p = 0.98) and overall survival (98.4%, 94.7%, and 93.5% vs. 99.3%, 95.8%, and 94.9%, respectively, p = 0.48). The propensity score-weighted population showed similar results. In Cox models involving covariates adjustment, propensity score-weighting, competing risk regression, and time-dependent covariates adjustment, both groups showed a similar risk of HCC recurrence and overall death. In subgroup analyses stratified according to HCC burden (Milan criteria, Up-to-7 criteria, French alpha-fetoprotein risk score), pretransplantation locoregional therapy, and salvage LT, neither ETV nor TDF was superior. In conclusion, ETV and TDF showed mutual noninferiority for HCC outcomes when used for HBV prophylaxis after LT.

Guidelines for the Prevention and Treatment of Chronic Hepatitis B (version 2022)

To facilitate the achieving of the goal of "eliminating viral hepatitis as a major public health threat by 2030" set by the World Health Organization, the Chinese Society of Hepatology together with the Chinese Society of Infectious Diseases (both are branches of the Chinese Medical Association) organized a panel of experts and updated the guidelines for prevention and treatment of chronic hepatitis B in China (version 2022). With the support of available evidence, this revision of the guidelines focuses on active prevention, large scale testing, and expansion of therapeutic indication of chronic hepatitis B with the aim of reducing the hepatitis B related disease burden.

Are the New Nucleos(t)ide Analogs Better than the Old Nucleos(t)ide Analogs?

In treatment-naïve patients with chronic hepatitis B virus (HBV) infection, entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide have a minimal or no risk of drug-resistance. These 3 nucleos(t)ide analog agents are highly potent inducing high rate of virologic response (reducing serum HBV DNA to levels undetectable by polymerase chain reaction assays) in most treatment-naïve patients. Our randomized trials have demonstrated that monotherapy with TDF can provide a successful virological response in most of the heavily pretreated patients with multidrug resistance to ETV or adefovir.

Hepatocellular Carcinoma and Hepatitis: Advanced Diagnosis and Management with a Focus on the Prevention of Hepatitis B-Related Hepatocellular Carcinoma

Though the world-wide hepatitis B virus (HBV) vaccination program has been well completed for almost thirty years in many nations, almost HBV-related hepatocellular carcinoma (HCC) occurs in unvaccinated middle-aged and elderly adults. Apparently, treating 80% of qualified subjects could decrease HBV-related mortality by 65% in a short period. Nevertheless, globally, only 2.2% of CHB patients undergo antiviral therapy. The HBV markers related to HCC occurrence and prevention are as follows: the HCC risk is the highest at a baseline of HBV DNA of 6-7 log copies/mL, and it is the lowest at a baseline of an HBV DNA level of >8 log copies/mL and ≤4 log copies/mL (parabolic, and not linear pattern). The titer of an HBV core-related antigen (HBcrAg) reflecting the amount of HBV covalently closed circular DNA (ccc DNA) in the liver is related to HCC occurrence. The seroclearance of HBs antigen (HBsAg) is more crucial than HBV DNA negativity for the prevention of HCC. In terms of the secondary prevention of hepatitis B-related HCC involving antiviral therapies with nucleos(t)ide analogues (NAs), unsolved issues include the definition of the immune-tolerant phase; the optimal time for starting antiviral therapies with NAs; the limits of increased aminotransferase (ALT) levels as criteria for therapy in CHB patients; the normalization of ALT levels with NAs and the relation to the risk of HCC; and the relation between serum HBV levels and the risk of HCC. Moreover, the first-line therapy with NAs including entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) remains to be clarified. Discussed here, therefore, are the recent findings of HBV markers related to HCC occurrence and prevention, unsolved issues, and the current secondary antiviral therapy for the prevention of HBV-related HCC.

Lower risk of hepatocellular carcinoma with tenofovir than entecavir in antiviral treatment-naïve chronic hepatitis B patients: a systematic review and meta-analysis involving 90,897 participants

Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are equally recommended as first-line treatments for antiviral treatment-naïve (ART-naïve) chronic hepatitis B (CHB) patients by practice guidelines because of their similarly high antiviral efficacy and low resistance rate. However, whether one is superior to the other in terms of hepatocellular carcinoma (HCC) prevention is currently largely controversial. We aimed to identify and synthesize these existing studies regarding the HCC risk of these two highly potent antivirals in treatment-naïve CHB patients. PubMed, EMBASE, and Cochrane Library were searched for studies between January 1, 2012 and June 25, 2022. These studies used ETV monotherapy and/or TDF monotherapy to treat ART-naïve CHB patients and reported the incidence of HCC. The extracted data were analyzed using a DerSimonian-Laird random-effects models. The HCC incidence difference was expressed as hazard ratio (HR) and 95% confidence interval (95% CI). A total of 17 studies with 90,897 ART-naïve CHB patients (ETV = 60,980 vs TDF = 29,917) were included in this meta-analysis. Compared with ETV, TDF was associated with a significant lower cumulative incidence of HCC (HR 0.66; 95% CI 0.56-0.76). No significant heterogeneity or publication bias was found among the included studies (I2 = 48.1%, Begg's p = 0.363 and Egger's p = 0.748). TDF is associated with a lower risk of HCC compared with entecavir in ART-naïve CHB patients. The results suggest that TDF may be a better option for ART-naïve CHB patients with high HCC risks.

Inverse Propensity Score-Weighted Analysis of Entecavir and Tenofovir Disoproxil Fumarate in Patients with Chronic Hepatitis B: A Large-Scale Multicenter Study

Tenofovir disoproxil fumarate (TDF) is reportedly superior or at least comparable to entecavir (ETV) in preventing hepatocellular carcinoma (HCC) among chronic hepatitis B (CHB) patients; however, it remains controversial. This study aimed to conduct comprehensive comparisons between the two antivirals. CHB patients initially treated with ETV or TDF between 2012 and 2015 at 20 referral centers in Korea were included. The primary outcome was the cumulative incidence of HCC. The secondary outcomes included death or liver transplantation, liver-related outcome, extrahepatic malignancy, development of cirrhosis, decompensation events, complete virologic response (CVR), seroconversion rate, and safety. Baseline characteristics were balanced using the inverse probability of treatment weighting (IPTW). Overall, 4210 patients were enrolled: 1019 received ETV and 3191 received TDF. During the median follow-ups of 5.6 and 5.5 years, 86 and 232 cases of HCC were confirmed in the ETV and TDF groups, respectively. There was no difference in HCC incidence between the groups both before (p = 0.36) and after IPTW was applied (p = 0.81). Although the incidence of extrahepatic malignancy was significantly higher in the ETV group than in the TDF group before weighting (p = 0.02), no difference was confirmed after IPTW (p = 0.29). The cumulative incidence rates of death or liver transplantation, liver-related outcome, new cirrhosis development, and decompensation events were also comparable in the crude population (p = 0.24-0.91) and in the IPTW-adjusted population (p = 0.39-0.80). Both groups exhibited similar rates of CVR (ETV vs. TDF: 95.1% vs. 95.8%, p = 0.38), and negative conversion of hepatitis B e antigen (41.6% vs. 37.2%, p = 0.09) or surface antigen (2.8% vs. 1.9%, p = 0.10). Compared to the ETV group, more patients in the TDF group changed initial antivirals due to side effects, including decreased kidney function (n = 17), hypophosphatemia (n = 20), and osteoporosis (n = 18). In this large-scale multicenter study, ETV and TDF demonstrated comparable effectiveness across a broad range of outcomes in patients with treatment-naïve CHB during similar follow-up periods.

Hepatocellular carcinoma risk in patients with chronic hepatitis B receiving tenofovir- vs. entecavir-based regimens: Individual patient data meta-analysis

BACKGROUND & AIMS

The comparative risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) receiving tenofovir disoproxil fumarate (TDF) vs. entecavir (ETV) remains controversial. In this individual patient data (IPD) meta-analysis, we aimed to compare HCC risk between the two drugs and identify subgroups who may benefit more from one treatment than the other.

METHODS

Published meta-analyses, electronic databases and congress proceedings were searched to identify eligible studies through January 2021. We compared HCC risk between the two drugs using a multivariable Cox proportional hazards model with anonymised IPD from treatment-naïve patients with CHB receiving TDF or ETV for ≥1 year. Treatment effect consistency was explored in propensity score matching (PSM), weighting (PSW) and subgroup analyses for age, sex, hepatitis B e-antigen (HBeAg) positivity, cirrhosis and diabetes status.

RESULTS

We included 11 studies from Korea, Taiwan and Hong Kong involving 42,939 patients receiving TDF (n = 6,979) or ETV (n = 35,960) monotherapy. Patients receiving TDF had significantly lower HCC risk (adjusted hazard ratio [HR] 0.77; 95% CI 0.61-0.98; p = 0.03). Lower HCC risk with TDF was consistently observed in PSM (HR 0.73; 95% CI 0.59-0.88; p <0.01) and PSW (HR 0.83; 95% CI 0.67-1.03; p = 0.10) analyses and in all subgroups, with statistical significance in the ≥50 years of age (HR 0.76; 95% CI 0.58-1.00; p <0.05), male (HR 0.74; 95% CI 0.58-0.96; p = 0.02), HBeAg-positive (HR 0.69; 95% CI 0.49-0.97; p = 0.03) and non-diabetic (HR 0.79; 95% CI 0.63-1.00; p <0.05) subgroups.

CONCLUSION

TDF was associated with significantly lower HCC risk than ETV in patients with CHB, particularly those with HBeAg positivity. Longer follow-up may be needed to better define incidence differences between the treatments in various subgroups.

IMPACT AND IMPLICATIONS

Previous aggregate data meta-analyses have reported inconsistent conclusions on the relative effectiveness of tenofovir disoproxil fumarate and entecavir in reducing hepatocellular carcinoma risk in patients with chronic hepatitis B (CHB). This individual patient data meta-analysis on 11 studies involving 42,939 patients from Korea, Taiwan and Hong Kong suggested that tenofovir disoproxil fumarate-treated patients have a significantly lower hepatocellular carcinoma risk than entecavir-treated patients, which was observed in all subgroups of clinical interest and by different analytical methodologies. These findings should be taken into account by healthcare providers when determining the optimal course of treatment for patients with CHB and may be considered in ensuring that treatment guidelines for CHB remain pertinent.

Risk of Hepatocellular Carcinoma With Tenofovir vs Entecavir Treatment for Chronic Hepatitis B Virus: A Reconstructed Individual Patient Data Meta-analysis

IMPORTANCE

Conventional meta-analyses with aggregated study-level data have yielded conflicting results for the comparative effectiveness of tenofovir disoproxil fumarate vs entecavir in reducing hepatocellular carcinoma (HCC) risk among patients with chronic hepatitis B virus. Within-study heterogeneity, between-study heterogeneity, and the inability of conventional meta-analyses to capture time-to-event data were associated with these results.

OBJECTIVE

To perform a reconstructed individual patient data meta-analysis of high-quality propensity score-matched studies to provide robust estimates for comparative HCC risk between groups receiving tenofovir or entecavir.

DATA SOURCES

Medline and Embase databases were searched from inception to October 6, 2021.

STUDY SELECTION

The initial search yielded 3435 articles. Fourteen studies that used propensity score matching to balance baseline characteristics were included in the final analysis.

DATA EXTRACTION AND SYNTHESIS

The Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline was followed. Individual patient data were reconstructed from Kaplan-Meier curves. Risk of HCC was evaluated using random-effects hazard ratios (HRs) via a shared-frailty model and a Cox proportional hazards model stratified by study group. Restricted mean survival time (RMST) analysis was conducted to account for varying estimated treatment effect across time.

MAIN OUTCOMES AND MEASURES

The comparative risk of HCC with tenofovir vs entecavir treatment.

RESULTS

From analysis of 14 studes with 24 269 patients (10 534 receiving tenofovir and 13 735 receiving entecavir; mean age, 49.86 [95% CI, 48.35-51.36] years; 65.05% [95% CI, 58.60%-71.00%] men), tenofovir was associated with decreased HCC incidence compared with entecavir (stratified Cox HR, 0.85 [95% CI, 0.76-0.94] at 5 years; P = .002). However, there was no significant difference in subanalysis of clinical cohort studies (stratified Cox HR, 0.92 [95% CI, 0.80-1.06] at 5 years; P = .24). Among administrative database studies, proportionality was violated, and HRs could not be obtained via Cox proporational hazards-based models. The mean time to HCC development in RMST analysis was 2.8 (95% CI, 1.8-3.7) weeks longer (P < .001) for tenofovir vs entecavir at 5 years. The RMST analyses for other subgroups revealed either insignificant or minimal differences (<3 weeks) in the mean time to HCC at 5 years.

CONCLUSIONS AND RELEVANCE

In this meta-analysis, there was no clinically meaningful difference in the risk of HCC between patients who received entecavir and patients who received tenofovir. There was no difference between tenofovir and entecavir among clinical cohort studies, whereas the mean time to HCC development was less than 3 weeks longer for patients who received tenofovir vs those who received entecavir at year 5 among administrative database studies. The choice between tenofovir or entecavir should be decided based on patient convenience and tolerability.

Systematic Review with Meta-Analysis: Comparison of the Risk of Hepatocellular Carcinoma in Antiviral-Naive Chronic Hepatitis B Patients Treated with Entecavir versus Tenofovir: The Devil in the Detail

Simple Summary

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are the preferred anti-viral agents used as first-line treatments for chronic hepatitis B. Despite many meta-analyses being conducted, it is still not clear whether TDF is more effective than ETV at reducing the risk of HCC due to the inconsistent statistical methodologies employed in previous observational studies. To reduce heterogeneity, we analysed only hospital cohort data studies with anti-viral naive patients. Additionally, unlike previous studies, we conducted subgroup analyses with enrolment criteria and socioeconomic factors that could not be corrected with statistical techniques. There is no difference between the two drugs in terms of reducing the risk of HCC in a pooled analysis of PS-matched patients. In the subgroup analysis, if there was interval of over three years from the start point of patient enrolment, we found that TDF was associated with significantly lower HCC risk. This result will provide new perspectives for future research.

Abstract

Tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are the preferred anti-viral agents used as first-line treatments for chronic hepatitis B (CHB). However, the efficacy of these agents in reducing the incidence of hepatocellular carcinoma (HCC) remains unclear. We conducted this meta-analysis to assess the efficacy of anti-viral agent on preventing HCC in CHB. Two investigators independently searched all relevant studies that examined the efficacy of anti-viral agent for preventing HCC using MEDLINE, Embase, and Cochrane Library databases through August 2021. The extracted data were analysed using a random-effects meta-analysis model based on the inverse-variance method (DerSimonian–Laird) and expressed as hazard ratio (HR) and 95% confidence interval (95% CI). We included 19 retrospective studies in the analysis. Although there was substantial heterogeneity between the studies, the overall pooled HR indicated that TDF significantly lowered the risk of HCC (HR: 0.72, 95% CI: 0.58–0.90, I² = 66.29%). However, the pooled analysis of propensity score (PS)-matched subpopulations showed no significant differences (HR, 0.83; 95% CI, 0.65–1.06; I² = 52.30%) between TDF and ETV. In a subgroup analysis, an interval of over three years in the start point of patient enrolment and excluding alcoholic liver disease patients significantly lowered the HCC risk associated with TDF. In conclusion, TDF may be more effective than ETV at reducing HCC incidence in treatment-naive CHB patients, but this effect was not consistent in the PS-matched subpopulation that reduced heterogeneity. As a result of subgroup analysis, the conflicting findings of previous studies may result from heterogeneous inclusion criteria. Further studies with standardised protocols are needed to reduce the residual heterogeneity.

Lower risk of hepatocellular carcinoma with tenofovir than entecavir treatment in subsets of chronic hepatitis B patients: an updated meta-analysis

BACKGROUND AND AIM

Previous smaller meta-analyses comparing the incidence of hepatocellular carcinoma (HCC) in chronic hepatitis B (CHB) patients treated with tenofovir disoproxil fumarate (TDF) versus entecavir (ETV) provided controversial results. This updated meta-analysis aimed to reliably identify any difference in the HCC incidence between TDF-treated or ETV-treated CHB patients in general or in specific subgroups.

METHODS

PubMed, EMBASE, Web of Science, and Cochrane Library were systematically searched for relevant studies with hazard ratios (HRs) for HCC between TDF-treated and ETV-treated CHB patients. Retrieved dates ranged from January 2009 to October 2021. HRs with or without adjustment were pooled with random-effects model.

RESULTS

Twenty-four comparative studies involving 37 771 CHB patients treated with TDF and 72 094 treated with ETV were included. TDF was associated with lower risk of HCC compared with ETV, with pooled unadjusted HR of 0.76 (95% confidence interval [CI]: 0.67-0.86) (24 studies) and adjusted HR of 0.81 (95% CI: 0.72-0.91) (21 studies). In propensity score matching cohorts, the TDF superiority was confirmed for unadjusted HR 0.83 (95% CI: 0.71-0.97) (14 studies) and was close to significance for adjusted HR (0.78, 95% CI: 0.58-1.04) (8 studies). Subgroup analyses showed that TDF was associated with lower HCC risk than ETV treatment in CHB patients who were from Asia (adjusted HR: 0.76, 95% CI: 0.66-0.87; 15 studies) or nucleos(t)ide naïve (adjusted HR:0.74, 95% CI: 0.65-0.84; 18 studies).

CONCLUSION

Current evidence from a sizable population suggests that TDF is associated with significantly lower HCC risk compared with ETV treatment in patients who are from Asia and/or nucleos(t)ide naïve.