Biannual Ultrasound Helps Spot Early Liver Cancer
By David Douglas
NEW YORK (Reuters Health) Jun 26 - In cirrhotic patients, biannual ultrasonography may have advantages over annual computed tomography for detecting early hepatoma, researchers suggest.
Whether early detection will reduce mortality is another question, however.
"No appropriately designed study has ever shown a mortality benefit" of screening for early hepatocellular carcinoma (HCC), said study coauthor Dr. Christine Pocha, of Minneapolis VAHCS System, Minnesota, in email to Reuters Health.
"More importantly," she continued, "surveillance programs must recognize the limitations in HCC surveillance tests and treatment efficacy in specific patient populations."
Still, she added, ultrasound screening has been recommended for more than a decade. Alpha-fetoprotein (AFP) levels were used until recently as well, although that marker has now been dropped officially because of a lack of sensitivity.
There's no consensus on screening intervals, however, and now some providers have started to use computed tomography (CT), as Dr. Pocha's team points out in a June 10 online paper in Alimentary Pharmacology and Therapeutics.
In the current study, the researchers sought to evaluate CT screening, thinking it would detect smaller tumors at lower overall cost.
They randomized 163 Veterans Health Administration patients with compensated cirrhosis to biannual ultrasonography (US) or yearly triple-phase-contrast CT. In addition, patients had AFP testing twice per year.
The HCC incidence was 6.6% per year. Nine HCCs were detected by US and eight by CT. Sensitivity and specificity rates, respectively, were 71.4% and 97.5% with US vs 66.7% and 94.4% with CT.
The biannual AFP testing added little to overall HCC detection, the investigators say. They add, however, that its cost was low, and one patient was identified by increasing AFP level, although initial imaging was negative.
But while 58.8% of HCCs were detected at an early stage, only 23.5% of patients received potentially curative treatment, and only one patient received a liver transplant. HCC-related mortality was 70.5% and overall mortality was 82.3%, suggesting that most patients died of their cancer.
The researchers conclude that biannual US was marginally more sensitive and less costly than annual CT for detecting early HCC. Because of the costs and the risks involved in CT, they say it "should not be used as screening tool for a population at risk for HCC."
Advances in screening technologies and HCC treatments "may provide further incremental improvements in the cost/effectiveness equation," Dr. Pocha told Reuters Health.
But in the meantime, her team concludes in its paper, "The overall efficacy of HCC surveillance in a cirrhotic population in the United States has yet to be demonstrated, and further research is needed."
Aliment Pharmacol Ther 2013.
Guidelines recommend screening for hepatocellular cancer (HCC) with ultrasonography. The performance of ultrasonography varies widely. Computed tomography (CT) is less operator dependent.
To compare the performance and cost of twice-a-year ultrasonography to once-a-year triple-phase-contrast CT for HCC screening in veterans. We hypothesised that CT detects smaller HCCs at lower overall cost.
One hundred and sixty-three subjects with compensated cirrhosis were randomised to biannual ultrasonography or yearly CT. Twice-a-year alpha-feto protein testing was performed in all patients. Contingency table analysis using chi-squared tests was used to determine differences in sensitivity and specificity of screening arms, survival analysis with Kaplan–Meier method to determine cumulative cancer rates. Multivariate logistic regression models were used to examine predictive factors.
Hepatocellular cancer incidence rate was 6.6% per year. Nine HCCs were detected by ultrasonography and eight by CT. Sensitivity and specificity were 71.4% and 97.5%, respectively, for ultrasonography vs. 66.7% and 94.4%, respectively, for CT. Although 58.8% of screen-detected HCC were early stage (Barcelona Clinic Liver Cancer stage A), only 23.5% received potentially curative treatment despite all treatment options being available. HCC-related and overall mortality were 70.5% and 82.3%, respectively, in patients with screen-detected tumour. Overall costs were less for biannual ultrasonography than annual CT.
Biannual ultrasonography was marginally more sensitive and less costly for detection of early HCC compared with annual CT. Despite early detection, HCC-related mortality was high. These data support the use of biannual ultrasonography for HCC surveillance in a US patient population (NCT01350167).