Radiographic response to locoregional embolization of hepatocellular carcinoma predicted survival, Dr. Khairuddin Memon and colleagues reported in the August issue of Gastroenterology.
The finding is the first to substantiate the prognostic value of tumor response to chemoembolization and radioembolization in hepatocellular carcinoma (HCC), they wrote (Gastroenterology 2011 August [doi: 10.1053/j.gastro.2011.04.054].
"Based on these findings, consideration should be made to develop treatments for HCC that not only prolong [time to progression], but also elicit radiographic tumor response," added Dr. Memon of the department of radiology at Northwestern Memorial Hospital in Chicago.
According to Dr. Memon, between 2000 and 2008, 463 patients with HCC were treated at the authors’ institution using transarterial locoregional therapies – either transarterial chemoembolization (TACE) or yttrium-90 radioembolization (Y). All of these patients had unresectable HCC and bilirubin levels less than 3.0 mg/dL.
For the present analysis, the authors subsequently excluded all patients who underwent transplant, exhibited portal venous thrombosis or extrahepatic metastases at baseline, or had a Child-Pugh score greater than B7.
Survival outcomes were analyzed for the remaining 159 patients with respect to their response to TACE or Y therapy. Most of the patients (74%) were male, and 40% were younger than 65 years of age.
Response status was assessed using both World Health Organization criteria and European Association for Study of the Liver (EASL) guidelines. Patients were assessed using computed tomography or magnetic resonance imaging at 1 month after treatment and then at scheduled 2- to 3-month intervals.
The authors found that patients who were responders at the 6-month posttreatment landmark according to WHO criteria had an overall median survival of 31.6 months, compared with 13.7 months for 6-month WHO nonresponders (P = .069).
Judging by EASL guidelines, however, the difference reached significance: 6-month landmark EASL responders had a median overall survival of 24.6 months, versus 13.2 months for nonresponders (P = .002).
Highly significant differences were found when the participants were divided into two groups based on response or nonresponse at 12 months. By WHO criteria, median overall survival for responders at 12 months was 36.4 months, versus 11.1 months for nonresponders (P = .004). And by EASL standards, median survival was also 36.4 months for responders, versus 9.7 months for nonresponders (P less than .0001).
The authors also analyzed risk of death in the 6 months following each landmark. They found that WHO responders at the 6-month landmark had a 6.6% rate of death in this window, versus 15.5% among nonresponders – a nonsignificant difference (P = .707).
However, according to EASL standards, the rate of death in the 6 months following the 6-month landmark was 4.7% among responders versus 20.6% among nonresponders (P = .046).
Moreover, the death rate in the 6 months following the 12-month landmark was 0% for WHO responders, versus 31.5% for nonresponders (P = .010), and it was 4% and 32.7%, respectively, by EASL guidelines (P = .013).
The authors added that baseline tumor size was not a significant factor affecting survival in a univariate analysis.
"Our data show that responders by WHO/EASL criteria live longer than nonresponders from the landmark onwards, with the exception of WHO 6-month landmark (near significance); the trend is clear," wrote the authors.
Randomized controlled trials "will be required to validate this concept and establish radiographic response as a surrogate of the true end point (survival)."
Dr. Memon and his fellow researchers declared no conflicts of interest associated with this study.