As mentioned earlier in this issue of TreatmentUpdate, reports from Barcelona and Vienna have emerged suggesting that exposure to direct acting antivirals (DAAs) in a small number of patients may somehow be associated with an increased risk for the recurrence or development of liver cancer. However, analyses of small databases can sometimes inadvertently produce biased conclusions.
To cast clarity on the possible association between the use of DAAs and the risk for the development or recurrence of liver cancer, researchers in France who were interested in assessing risks for liver cancer conducted a large review of three prospective studies. Each of these studies, for different reasons, collected data on more than 6,000 people who had been treated with these drugs. An analysis of such a large number of people is very powerful. Such large analyses help to reduce the risk of inadvertent bias that could occur when analyzing much smaller numbers of people.
The researchers found that rates of liver cancer recurrence were relatively low and that there was no increased risk for liver cancer or its recurrence among people who were treated with DAAs.
Study Details and Results
ANRS CO22 HEPATHER
By the end of 2015, this study had recruited more than 14,000 people with past or active HCV infection. A total of 5,458 people initiated treatment with DAAs. Researchers focused on 267 participants who had chronic active HCV and who had previously been treated for liver cancer. Researchers divided these 267 people into two groups as follows: 189 were subsequently treated with DAAs and 78 were not. The research team found three statistically significant differences between these two groups of people. Specifically, DAA users were more likely to have the following features:
- they were slightly younger (62 vs. 66 years)
- they were more likely to be men (78% vs. 73%)
- they were more likely to have scarring of their liver (78% vs. 63%)
However, the rate of recurrence of liver cancer was not significantly different between the two groups of participants.
The researchers also noted that there were five cases of liver cancer recurrence in people who received a combination of sofosbuvir + interferon + ribavirin. They stated that this undercuts support for the argument that interferon provides some sort of protection from the subsequent development of liver cancer.
ANRS CO12 CIRVIR
This study, which enrolled 1,822 people with cirrhosis (severe scarring of the liver), was focused on studying people with complications from cirrhosis. The French research team reviewed data collected on 1,354 participants who had cirrhosis caused by HCV infection. It is important to note that because participants had cirrhosis their risk for developing liver cancer was elevated.
The research team found 77 people who were in remission from liver cancer. Thirteen of these people subsequently received DAAs. One of these 13 (8%) had a recurrence of liver cancer three years later. In contrast, among the 66 remaining participants who did not receive DAAs, 31 recurrences (41%) occurred.
ANRS CO23 CUPILT
Participants in this study were enrolled so that doctors could monitor the impact of liver transplantation on their health. Researchers focused on 314 people who underwent liver transplantation and who subsequently received DAAs. A recurrence of liver cancer occurred in seven participants (2%). Five of these seven people died within five years of receiving the transplant. Researchers found that in five of these seven cases, based on analysis of the tumours from the first bout of liver cancer, it was likely that liver cancer would recur.
After searching through medical records and analysing data from three studies, which included participants with and without cirrhosis and some of whom had liver transplants, researchers found no evidence of an increased risk for the recurrence of liver cancer in patients who had been treated with DAAs.
This finding should reassure patients, doctors, nurses and pharmacists about the safety of DAAs. Furthermore, these findings are aligned with those from larger studies reported in TreatmentUpdate 215.
- Pol S. Lack of evidence of an effect of direct acting antivirals on the recurrence of hepatocellular carcinoma: The ANRS collaborative study group on hepatocellular carcinoma (ANRS CO22 HEPATHER, CO12 CIRVIR and CO23 CUPILT cohorts). Journal of Hepatology. 2016; in press.
- Lawitz E, Ruane P, Stedman C, et al. Long-term follow-up of patients with chronic HCV infection following treatment with direct-acting antiviral regimens: maintenance of SVR, persistence of resistance mutations and clinical outcomes. The International Liver Congress, 13-17 April 2016, Barcelona. Abstract 166.