Among patients with single-nodule hepatocellular carcinomas diagnosed by computed tomography, further imaging with gadoxetic acid–enhanced magnetic resonance (MR) revealed more tumors and was tied to a 28% drop in cancer recurrence and a 35% drop in mortality, a retrospective cohort study reported in the June issue of Gastroenterology ( doi.org/10.1053/j.gastro.2015.02.051 ) found.
“To the best of our knowledge, this is the first study to demonstrate that evaluation of hepatocellular carcinoma [HCC] with gadoxetic acid–enhanced MR imaging is associated with an improvement in the clinical outcome of patients, compared with that of a standard evaluation with dynamic CT,” said Dr. Hyung-Don Kim at the University of Ulsan in Seoul, South Korea and his associates. “This is clinically meaningful, given that the prognosis of patients with early-stage HCC is poor even after a curative treatment, mainly because of the high rate of early intrahepatic recurrence, and because there is no form of adjuvant therapy with a proven clinical benefit.” At least a third of early HCC recurrences might result from dissemination of primary tumor that went undetected at initial treatment, the researchers noted. To investigate the effects of gadoxetic acid–enhanced magnetic resonance imaging on HCC detection and subsequent survival, they retrospectively studied 700 patients in Seoul, South Korea, who had single-nodule HCCs diagnosed by dynamic four-phase CT. A total of 323 patients underwent additional imaging with gadoxetic acid–enhanced MR. These patients resembled CT-only patients in terms of baseline demographic characteristics, except that they were an average of 3 years younger (P < .001), had significantly higher median ALT levels (66 vs. 57 IU/mL; P < .006) and significantly higher platelet counts and lower alpha-fetoprotein levels, the investigators said.Gadoxetic acid–enhanced MR detected additional small HCC nodules in 16% of patients, and was tied to a 28% drop in likelihood of recurrence (hazard ratio, 0.72; 95% confidence interval, 0.54-0.96) and a 35% drop in risk of mortality (HR, 0.65; 95% CI, 0.44-0.96), the investigators reported. Rates of both recurrence-free and overall survival also were significantly higher for patients who underwent contrast-enhanced MR in addition to CT, compared with patients who underwent CT alone, and the differences held true in univariate, multivariate, inverse probability weighting analyses, and propensity score-matched analyses, they added.
“The major limitation of this study is that it was based on observational data,” commented the researchers. “Further studies that evaluate the effectiveness of gadoxetic acid–enhanced MR imaging for the evaluation of HCC in patients in other clinical settings are warranted.” The findings also need cautious interpretation because of the chance that selection bias led to more curable cases among patients who underwent MR in addition to CT, they said. The Korean Ministry of Health & Welfare and the Korean Association for the Study of Liver helped fund the research. One coauthor reported serving on the advisory boards of Bayer Healthcare, Bristol-Myers Squibb, and Gilead Science, and receiving research funding from Bayer, Gilead, and Novartis. The other investigators reported no conflicts of interest.