Survival benefit with intraarterial techniques in hepatocellular carcinoma

RESUMO

The two intraarterial techniques used in the treatment of hepatocellular carcinoma (HCC) are the transarterial chemoembolization (TACE) and radioembolization (RE). TACE includes various procedures whose objective is to expose tumor cells to a chemotherapy agent and induce acute ischemia in the tumor.

The survival benefit obtained by adding a chemotherapy agent or lipiodol to simple particle embolization has not been demonstrated in 2 meta-analyses, which suggests that the antitumor effect is primarily ischemic. RE is a form of brachytherapy that consists of an intraarterial injection of microspheres loaded with yttrium 90 as the source of radiation, a pure beta emitter with a mean tissue penetration of 2mm. TACE is performed in several sessions every 4-8 weeks, while RE is generally a single procedure.

The guidelines adopted by the main research societies support the use of TACE for the palliative treatment of patients with intermediate stage HCC. This is a level 1 recommendation based on the positive results of 2 randomized clinical trials and 3 meta-analyses and on several uncontrolled studies with thousands of patients with unresectable HCC. Survival in clinical practice studies is heterogeneous due to the heterogeneity of the treated population.

The survival rate varies from 8% to 26% at 5 years, and the median is 16-40 months in the early stage and 15-27 months in the intermediate stage. TACE with drug-eluting beads (DEB-TACE) has not shown superiority versus conventional TACE in terms of improved survival or tumor response, but it decreases the severe chemotherapy-related adverse events.

One of its advantages is the standardization of the procedure, while its primary disadvantage is the onset of biliary complications when used nonselectively. There is level 2 evidence to support the use of RE in HCC, evidence that comes from patient cohorts with consistent results and case-control studies.

The treated population includes mainly patients with unresectable tumors, who are considered suboptimal candidates for TACE or are progressing toward this condition, and those for whom TACE was directly contraindicated by the presence of portal vein thrombosis.

Consequently, these patients tend to have large or extensively bilobar tumors and other factors for a poor prognosis. The overall survival reported for patients in the intermediate and advanced stages is 16-18 months and 7-17 months, respectively.

 number of retrospective studies have reported comparable survival for patients treated with TACE and RE in the same institution; however, these results should be interpreted as a generator of ideas and not as an equivalent efficacy test. Although the combination of systemic agents such as sorafenib with intraarterial techniques is attractive, the results to date are not encouraging. In the only available randomized trial that compared the combination of a continuous regimen of sorafenib started before the first session of DEB-TACE versus DEB-TACE alone, neither the time to progression nor the overall survival were significantly different between the 2 groups.

TACE and RE are contraindicated in cases of decompensated cirrhosis. TACE is also contraindicated for patients with considerable tumor burden in whom the procedure cannot be performed selectively and in patients with portal vein invasion.

CITATION  Gastroenterol Hepatol. 2014 Jul;37 Suppl 2:95-101. doi: 10.1016/S0210-5705(14)70076-7.