Incidence of HCC recurrence after DAA treatment for HCV in a multicentre Italian cohort study

The present real‐life multicentre, prospective study aims to investigate the effects of direct‐acting antivirals (DAAs) in HCV patients with a previous successfully treated hepatocellular carcinoma (HCC), in terms of neoplastic recurrence and sustained virological response (SVR) rates.


| INTRODUC TI ON
Worldwide, 130-150 million people are estimated to be chronically infected with the hepatitis C virus (HCV). Cirrhosis develops in 10%-15% of patients with chronic HCV infection within 20 years, and in cirrhotic subjects, the risk of hepatocellular carcinoma (HCC) is estimated to be 3% to 7% per year. [1] Antiviral treatment of HCV infection has experienced a revolutionary advancement with the advent of direct-acting antivirals (DAAs), which can be administered in short, highly effective and well-tolerated interferon (IFN)free schedules, including in patients with decompensated cirrhosis or with a history of HCC. [2] In the interferon era, many studies have shown that cirrhotic patients achieving sustained virological response (SVR) had a reduced HCC development risk, with annual incidence rates of 1.2%-1.4% [3]; unfortunately, solid data concerning the risk of recurrence of successfully treated HCC in patients who obtained SVR are poor. [4] After the introduction of the new antiviral drugs, a controversial issue has arisen concerning their possible role in increasing the risk of HCC development and recurrence. [5][6][7][8][9][10][11][12][13][14] Recently, some prospective studies, including large cohorts of patients, demonstrated the absence of increased risk of HCC occurrence after successful DAA therapy. [9,[15][16][17][18] On the other hand, it is not straightforward to draw conclusions on the risk of HCC recurrence after DAAs [12] since multiple risk factors are involved. In particular, in this special setting it is necessary to take into account (a) the neoplastic risk related to the cirrhosis (higher risk in decompensated disease); (b) the risk factors related to the characteristics of the primary HCC (site, numbers of nodules, vascular invasion, etc) and (c) the lack of well-designed studies because of small sample size, retrospective designs without a control group of untreated HCV patients (ie patients not treated with DAAs), and heterogeneity of enrolled patients. [19] Furthermore, several publications about HCV-infected patients with previously successfully treated HCC highlighted that DAA-treated cohorts are older and show more advanced chronic liver disease in comparison to cohorts of IFN-treated patients, leading to higher HCC recurrence rates and making any comparison with historical IFN-treated controls suboptimal.
In this scenario, the recurrence of HCC has been reported as early recurrence (before 12 months) and late recurrence (after 12 months), according to the time of reappearance. An early recurrence is considered to have the same characteristics as the primary tumour, so its risk factors are tumour-related, such as tumour size, number of nodules and direct intrahepatic dissemination. Necro-inflammatory activity from chronic hepatitis and the fibrosis burden lead to underlined persistent carcinogenesis, which can be related to late 'de novo'

recurrence.
In light of all the aforementioned variables and of the limitations in the design of previous studies, it is very difficult to draw reliable conclusions. The present analysis of prospectively enrolled patients in a real-life multicentre study aims to investigate the effects of IFNfree DAA therapies on SVR rates and neoplastic recurrence in cirrhotic patients with HCV infection and a history of HCC who had achieved a complete radiological response after curative treatments or TACE.

| Study design and patient population
From March 2015 to March 2017, an observational, prospective, reallife study collecting consecutive cirrhotic patients infected by different HCV genotypes treated with any of the DAA regimens and with a history of successfully treated HCC (complete radiological response after curative treatments or TACE) was conducted in six community and academic Italian centres.
The study was performed in accordance with the principles of the

Key points
• New direct-acting antivirals (DAAs) are short, highly effective and well-tolerated therapy, also in patients with decompensated cirrhosis or with a history of hepatocellular carcinoma (HCC).
• DAAs treatment appears not to be associated with a major increased risk of HCC recurrence in our study.
• DAAs treatment failure, levels of total bilirubin, BMI and levels of AFP can be used to stratify the risk of HCC recurrence 3 months) and at least one tumour status imaging assessment after the antiviral therapy.
Patients with any of the following features were excluded: absence of cirrhosis, active HCC, treated HCC but without a radiological complete response and/or the presence of 'non-characterized nodules' on imaging before starting DAAs, human immunodeficiency virus (HIV) or hepatitis B virus (HBV) coinfection, liver-transplant recipients, history of alcohol intake and iron or copper metabolism disorders.
The choice of antiviral schedule therapy was left to the clinician's discretion, in accordance with national and international guidelines. [22,23] For each enrolled patient, demographic characteristics and clinical parameters at baseline were recorded: sex, body mass index (BMI), age, prior antiviral treatment, cirrhotic status and signs of portal hypertension, enlisting for orthotopic liver transplantation (OLT), presence of comorbidities and characteristics of HCC. In addition, the following biochemical parameters were registered: albumin, total bilirubin, creatinine, international normalized ratio (INR), blood count and alpha-1 fetoprotein (AFP).

| Follow-up and outcomes
The baseline characteristics, laboratory data and radiological [20] HCC recurrences were treated, whenever possible, according to the Barcelona Clinic Liver Cancer (BCLC) schedule and EASL guidelines. [20] Finally, we recorded the patients' status (alive/death) at the end of follow-up. Overall, the median follow-up from DAA start until the present analysis was 24.7 months (range: 12-36.9).
The assessment of neoplastic recurrence was the primary outcome in this study. The secondary outcomes were the baseline characteristics that could predict HCC recurrence, including the SVR, defined as the persistent absence of detectable serum HCV-RNA 12 weeks after the end of treatment.

| Statistical analysis
Baseline characteristics of patients were summarized using standard descriptive statistics and compared between groups (subjects with and without recurrence) using either the T test for independent samples, the Mann-Whitney U test, the chi-square test or the Fisher exact test.
Median follow-up was computed according to the reverse Kaplan-Meier technique using DAA initiation as a starting point.
Recurrence incidence rates were calculated as per 100 person-years, and the corresponding 95% CIs were estimated assuming a Poisson distribution for the number of events. Cumulative probabilities of recurrence were extracted from time-to-event curves based on the Kaplan-Meier product limit method. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using univariate and multivariate Cox regressions. The proportional hazard assumption was tested using the method of Grambsch and Therneau. [24] In Cox models, SVR was not considered a time-dependent variable. For all statistical comparisons, a P < .05 was accepted as statistically significant. All analyses were performed using r version 3.4.1 (www.r-proje ct.org).

| Patients characteristics and follow-up
The baseline demographic, clinical and laboratory characteristics of the enrolled patients are summarized in Table 1.
There were 101 patients treated with DAAs in the defined time period. The majority of patients were male (65/101, 64.4%), and the mean age was 67.2 ± 7.8 years. The mean BMI was 25.8 ± 3 kg/m 2 .

| Recurrence probabilities analysis and timing evaluation
The overall rate of HCC recurrence was 30 (Table S2).
Additionally, we divided our population into two subgroups according to DAA initiation time from last HCC treatment (before and after 6 months). We found no statistically significant difference between the two subgroups (Table S3).

| D ISCUSS I ON
The present real-life multicentre prospective study showed a cumulative rate of HCC recurrence of 20.5 per 100 person-years in a median observational follow-up of 31.7 months from DAA initiation.
In particular, the 6-, 12-and 24-months HCC recurrence rates from the last HCC treatment were 1%, 8.9% and 25.6% respectively. These data are in contrast with first reports describing early, unexpected increases in HCC recurrence after HCV elimination with DAA therapy, [5,7] but they are in line with the few more recent papers countering the alarmist results initially observed. [9,16,[25][26][27][28] Of note, a useful benchmark for indirect comparisons of the bene-  In conclusion, our prospective study failed to show any negative impact of DAA treatment on the incidence of HCC recurrence. The risk of HCC recurrence in our cohort was comparable and not higher than that observed in HCV-untreated patients. DAA treatment failure, level of total bilirubin, BMI and level of AFP can be used to stratify the risk of HCC recurrence and the schedule of the surveillance protocol. Successful HCV therapy with DAAs is probably not likely to prevent per se early recurrence of HCC, but surely it improves liver function, decreasing the risk of death from end-stage liver disease.
For all these reasons, we conclude that there is no need to hold back from DAA therapy in patients with a history of HCC after ascertaining that the tumour is fully controlled and a complete radiological response has been achieved.