Abbreviated magnetic resonance imaging vs ultrasound for surveillance of hepatocellular carcinoma in high-risk patients

Advancing Surveillance Strategies for Hepatocellular Carcinoma: A New Era of Efficacy and Precision

Hepatocellular carcinoma (HCC) is one of the few cancers with a 5-year survival that has remained below 20%; however, prognosis differs by tumor stage at diagnosis. Curative treatment options among patients with early-stage HCC afford a median survival of 5-10 years. Accordingly, international society guidelines recommend semi-annual HCC surveillance in at-risk patients, including those with cirrhosis or high-risk chronic hepatitis B infection. Surveillance is associated with increased early-stage HCC detection and curative treatments, leading to reduced HCC-related mortality. Abdominal ultrasound has been the cornerstone for HCC surveillance for the past two decades, but recent data have highlighted its suboptimal sensitivity for early-stage HCC detection, particularly in patients with obesity and those with non-viral etiologies of liver disease. The combination of ultrasound plus alpha fetoprotein (AFP) has higher sensitivity for early-stage HCC detection than ultrasound alone, although the combination still misses over one-third of HCC at an early stage. Emerging imaging and blood-based biomarker strategies have promising data in biomarker phase 2 (case-control) and phase 3 (cohort) studies. Beyond ultrasound, Magnetic resonance imaging (MRI) is the best-studied imaging strategy, with superior sensitivity and specificity compared to ultrasound in a cohort study. Abbreviated MRI protocols have been proposed to address concerns about MRI radiological capacity, costs, and patient acceptance. Of biomarker strategies, GALAD (a panel including gender, age, AFP, AFP-L3, and DCP) is the best validated, with promising sensitivity for early-stage HCC detection in a national multi-center cohort study. Liquid biopsy biomarkers, including methylated DNA markers, have also shown promising accuracy in case-control studies. Abbreviated MRI and GALAD are now entering prospective trials that examine clinical outcomes such as early-stage HCC detection and screening-related harms, which are essential data to understand for adoption in clinical practice. As additional surveillance strategies become available, it will allow an era of precision surveillance in which optimal surveillance modalities are tailored to individual patient risk and expected test performance.

Cost-effectiveness of a precision hepatocellular carcinoma surveillance strategy in patients with cirrhosis

Background

Hepatocellular carcinoma (HCC) surveillance is currently performed using a one-size-fits-all strategy with ultrasound plus AFP (US + AFP). There is increasing interest in risk-stratified and precision surveillance strategies incorporating individual risk and variance in surveillance test performance; however, the cost-effectiveness of these approaches has not been evaluated.

Methods

We conducted a cost-effectiveness analysis to evaluate four surveillance strategies (no surveillance, universal US + AFP surveillance, risk-stratified surveillance, and precision surveillance) in a simulated cohort of 50-year-old patients with compensated cirrhosis. The most cost-effective strategy was that with the highest incremental cost-effectiveness ratio (ICER) and below the willingness-to-pay (WTP) threshold of $150,000/QALY gained. Model inputs were based on literature review, and costs were derived from the Medicare fee schedule.

Findings

The precision surveillance strategy demonstrated variation in recommended surveillance test based on HCC risk category and patient factors. US + AFP, risk-stratified, and precision surveillance detected more HCC cases per 100,000 population than no surveillance, with a higher proportion of early-stage cases for precision surveillance (67.6%) than risk-stratified (63.8%), universal ultrasound (63.2%), and no surveillance (38.0%). Compared to no surveillance, precision surveillance was most cost-effective, with an ICER of $104,614/QALY gained, whereas US + AFP and risk-stratified surveillance were both dominated. Compared to US + AFP, risk-stratified surveillance was cost saving and dominated US + AFP, whereas precision surveillance was cost-effective, with an ICER of $98,103/QALY gained. Results were sensitive to survival with early-stage HCC, cost of early-stage HCC treatment, and surveillance utilization. Precision surveillance remained the most cost-effective when WTP thresholds exceeded $110,000/QALY gained.

Interpretation

A precision surveillance strategy is the most cost-effective method for HCC surveillance. This approach could maximize surveillance benefits in high-risk patients, while minimizing surveillance harms in low-risk individuals.

Funding

National Cancer Institute (U01 CA230694, R01 CA222900, R01 CA212008, and U24ca086368) and Cancer Prevention Research Institute of Texas (CPRIT) (RP200554).

Prospective Study of Non-Contrast, Abbreviated MRI for Hepatocellular Carcinoma Surveillance in Patients with Suboptimal Hepatic Visualisation on Ultrasound

BACKGROUND

Biannual ultrasound (US) is recommended for hepatocellular carcinoma (HCC) surveillance in patients with cirrhosis. However, US has limited sensitivity for early-stage HCC, particularly in overweight cohorts, where hepatic visualisation is often inadequate. Currently there are no robust imaging surveillance strategies in patients with inadequate US visualisation. We investigated the ability of non-contrast, abbreviated magnetic resonance imaging (aMRI) to adequately visualise the liver for HCC surveillance in patients with previously inadequate US.

METHODS

Patients undergoing US surveillance, where liver visualisation was inadequate (LI-RADS VIS-B and VIS-C), were prospectively recruited. Patients underwent non-contrast T2-weighted and diffusion-weighted aMRI. The images were reviewed and reported by an expert liver radiologist. Three independent, blinded radiologists assessed the aMRI visualisation quality using a binary score assessing five parameters (parenchymal definition, vascular definition, coverage of the liver, uniformity of liver appearance and signal-to-noise ratio).

RESULTS

Thirty patients completed the aMRI protocol. The majority (90%) had underlying cirrhosis and were overweight (93.3%), with 50% obese and 20% severely obese. A total of 93.3% of the aMRI scans were of satisfactory quality. Six patients (20%) had hepatic abnormalities detected with aMRI that were not seen on their US: one HCC, one haemangioma and three clinically insignificant lesions. For the aMRI visualisation quality assessment, the coverage of the liver, vascular definition and parenchymal definition were consistently rated to be of sufficient quality by all three radiologists.

CONCLUSIONS

Non-contrast aMRI provided good visualisation of the liver and detection of abnormalities in patients with inadequate US. aMRI should be further explored in a larger, prospective study as an alternative surveillance strategy in patients with inadequate US.

PNPLA3 risk allele is associated with risk of hepatocellular carcinoma but not decompensation in compensated cirrhosis

BACKGROUND

The PNPLA3-rs738409-G, TM6SF2-rs58542926-T, and HSD17B13-rs6834314-A polymorphisms have been associated with cirrhosis, hepatic decompensation, and HCC. However, whether they remain associated with HCC and decompensation in people who already have cirrhosis remains unclear, which limits the clinical utility of genetics in risk stratification as HCC is uncommon in the absence of cirrhosis. We aimed to characterize the effects of PNPLA3, TM6SF2, and HSD17B13 genotype on hepatic decompensation, HCC, and liver-related mortality or liver transplant in patients with baseline compensated cirrhosis.

METHODS

We conducted a single-center retrospective study of patients in the Michigan Genomics Initiative who underwent genotyping. The primary predictors were PNPLA3, TM6SF2, and HSD17B13 genotypes. Primary outcomes were either hepatic decompensation, HCC, or liver-related mortality/transplant. We conducted competing risk Fine-Gray analyses on our cohort.

RESULTS

We identified 732 patients with baseline compensated cirrhosis. During follow-up, 50% of patients developed decompensation, 13% developed HCC, 24% underwent liver transplant, and 27% died. PNPLA3-rs738409-G genotype was associated with risk of incident HCC: adjusted subhazard hazard ratio 2.42 (1.40-4.17), p=0.0015 for PNPLA3-rs738409-GG vs. PNPLA3-rs738409-CC genotype. The 5-year cumulative incidence of HCC was higher in PNPLA3-rs738409-GG carriers than PNPLA3-rs738409-CC/-CG carriers: 15.6% (9.0%-24.0%) vs. 7.4% (5.2%-10.0%), p<0.001. PNPLA3 genotype was not associated with decompensation or the combined outcome of liver-related mortality or liver transplant. TM6SF2 and HSD17B13 genotypes were not associated with decompensation or HCC.

CONCLUSIONS

The PNPLA3-rs738409-G allele is associated with an increased risk of HCC among patients with baseline compensated cirrhosis. People with cirrhosis and PNPLA3-rs738409-GG genotype may warrant more intensive HCC surveillance.

The Future Role of Abdominal US in Hepatocellular Carcinoma Surveillance

Abdominal US is currently the best-validated surveillance strategy for hepatocellular carcinoma (HCC) in at-risk patients. It is the only modality shown to have completed all five phases of validation and can achieve high sensitivity and specificity for HCC detection, especially when conducted by expert sonographers in high-volume centers. However, US also has limitations, including operator dependency and varying sensitivity in clinical practice. Further, the sensitivity of US for early-stage HCC detection is lower in patients with obesity or nonviral liver disease, increasingly common populations undergoing surveillance. Imaging-based and blood-based surveillance strategies, including abbreviated MRI and biomarker panels, may overcome some limitations of US-based surveillance. Both strategies have promising test performance in phase II and phase III biomarker studies and are undergoing prospective validation. Considering the variation in HCC risk and test performance between patients, there will likely be a shift away from a one-size-fits-all approach and toward precision screening, in which the "best" test is selected based on individual patient characteristics. In this upcoming era of precision HCC screening among patients with cirrhosis, US will likely continue to have an important, albeit reduced, surveillance role.

Abbreviated magnetic resonance imaging in hepatocellular carcinoma surveillance: A review

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies of the liver and a leading cause for cancer-related deaths worldwide. HCC surveillance aims at early detection. The recommended strategy for screening HCC is biannual ultrasound with or without alpha-fetoprotein. However, this strategy is associated with sub-optimal sensitivity. Abbreviated magnetic resonance imaging (AMRI) is a promising alternative to ultrasound (US) for surveillance of HCC. The data regarding the role of AMRI in HCC screening is evolving. There are different AMRI protocols, each having its merits and disadvantages. In this review, we discuss the need for AMRI, protocols of AMRI and hindrances to widespread adoption of AMRI.

NAFLD and NAFLD-related HCC in Asia: Burden and Surveillance

Non-alcoholic fatty liver disease (NAFLD) is rapidly emerging as a leading etiology of chronic liver disease (CLD) in Asia. The increasing incidence of NAFLD is projected to drive a surge in NAFLD-related hepatocellular carcinoma (HCC). A notable characteristic of NAFLD-HCC is its capacity for development in individuals without cirrhosis in more than a third of patients. Most practice guidelines recommend biannual ultrasound screening for patients with cirrhosis. In cases of severe limitations to ultrasound visualisation, cross-sectional abdominal imaging may be warranted. Improved strategies for HCC risk stratification are required for people with NAFLD but without cirrhosis. In this Review, we discuss the evolving trends of NAFLD and HCC in Asia, and implications for surveillance.

Hepatocellular carcinoma surveillance may be associated with potential psychological harms in patients with cirrhosis

BACKGROUND AND AIMS

The value of HCC surveillance is determined by the balance between benefits and harms; however, no studies have enumerated psychological harms.

APPROACH AND RESULTS

We fielded surveys measuring psychological harms to patients with cirrhosis in a multicenter randomized trial of HCC surveillance outreach. All patients with positive or indeterminate surveillance results and matched patients with negative results were invited to complete surveys measuring (1) depression through the Patient Health Questionnaire-ninth version, (2) anxiety through State-Trait Anxiety Inventory, (3) HCC-specific worry through Psychological Consequences Questionnaire, and (4) decisional regret. Patients were classified into 4 groups: true positive (TP), false positive (FP), indeterminate, and true negative (TN). Multivariable longitudinal regression analysis using the generalized estimating equation method was performed to compare the means of measures across groups. We conducted 89 semistructured interviews in a subset of patients stratified by health system and test results. Of 2872 patients in the trial, 311 completed 1+ follow-up survey (63 FP, 77 indeterminate, 38 TP, and 133 TN). Moderate depression decreased in TN patients, increased in TP, and had intermittent but mild increases in those with FP and indeterminate results. High anxiety temporarily increased in patients with TP results but resolved over time and was stable in those with FP and indeterminate results. Decisional regret was low and did not differ across groups. In semistructured interviews, patients reported apprehension, anxiety, emotional distress, and coping related to HCC surveillance.

CONCLUSIONS

Psychological harms of HCC surveillance appear mild but differ by test result. Future research should determine the impact of psychological harms on the value of HCC surveillance programs.

Hepatocellular Carcinoma Surveillance: Evidence-Based Tailored Approach

Hepatocellular carcinoma (HCC) surveillance is recommended by professional society guidelines given a consistent association with reduced HCC-related mortality. HCC surveillance should be performed using semiannual abdominal ultrasound and alpha-fetoprotein, although this combination has suboptimal sensitivity and can miss more than one-third of HCC at an early stage. There are promising emerging blood-based and imaging-based strategies, including abbreviated MRI and biomarker panels; however, these require further validation before routine use in clinical practice. HCC surveillance is underused in clinical practice due to patient-related and provider-related barriers, highlighting a need for interventions to improve surveillance utilization in clinical practice.

A rapid, non-invasive, clinical surveillance for CachExia, sarcopenia, portal hypertension, and hepatocellular carcinoma in end-stage liver disease: the ACCESS-ESLD study protocol

BACKGROUND

Liver cirrhosis, the advanced stage of many chronic liver diseases, is associated with escalated risks of liver-related complications like decompensation and hepatocellular carcinoma (HCC). Morbidity and mortality in cirrhosis patients are linked to portal hypertension, sarcopenia, and hepatocellular carcinoma. Although conventional cirrhosis management centered on treating complications, contemporary approaches prioritize preemptive measures. This study aims to formulate novel blood- and imaging-centric methodologies for monitoring liver cirrhosis patients.

METHODS

In this prospective study, 150 liver cirrhosis patients will be enrolled from three Swedish liver clinics. Their conditions will be assessed through extensive blood-based markers and magnetic resonance imaging (MRI). The MRI protocol encompasses body composition profile with Muscle Assement Score, portal flow assessment, magnet resonance elastography, and a abbreviated MRI for HCC screening. Evaluation of lifestyle, muscular strength, physical performance, body composition, and quality of life will be conducted. Additionally, DNA, serum, and plasma biobanking will facilitate future investigations.

DISCUSSION

The anticipated outcomes involve the identification and validation of non-invasive blood- and imaging-oriented biomarkers, enhancing the care paradigm for liver cirrhosis patients. Notably, the temporal evolution of these biomarkers will be crucial for understanding dynamic changes.

TRIAL REGISTRATION

Clinicaltrials.gov, registration identifier NCT05502198. Registered on 16 August 2022. Link: https://classic.

CLINICALTRIALS

gov/ct2/show/NCT05502198 .

Hepatocellular carcinoma surveillance - utilization, barriers and the impact of changing aetiology

Hepatocellular carcinoma (HCC) is the third leading cause of cancer death worldwide. Surveillance for HCC is critical for early detection and treatment, but fewer than one-quarter of individuals at risk of HCC undergo surveillance. Multiple failures across the screening process contribute to the underutilization of surveillance, including limited disease awareness among patients and health-care providers, knowledge gaps, and difficulty recognizing patients who are at risk. Non-alcoholic fatty liver disease and alcohol-associated liver disease are the fastest-rising causes of HCC-related death worldwide and are associated with unique barriers to surveillance. In particular, more than one-third of patients with HCC related to non-alcoholic fatty liver disease do not have cirrhosis and therefore lack a routine indication for HCC surveillance on the basis of current practice guidelines. Semi-annual abdominal ultrasound with measurement of α-fetoprotein levels is recommended for HCC surveillance, but the sensitivity of this approach for early HCC is limited, especially for patients with cirrhosis or obesity. In this Review, we discuss the current status of HCC surveillance and the remaining challenges, including the changing aetiology of liver disease. We also discuss strategies to improve the utilization and quality of surveillance for HCC.

Global trends in hepatocellular carcinoma epidemiology: implications for screening, prevention and therapy

Hepatocellular carcinoma (HCC) mortality rates are increasing globally, and particularly in the Western world. Cirrhosis remains the predominant risk factor for HCC. However, epidemiological shifts in the incidence of HCC from patients with virus-related liver disease to those with non-viral aetiologies, including alcohol-associated and metabolic dysfunction-associated steatotic liver disease, have important implications for prevention, surveillance and treatment. Hepatitis B vaccination and antiviral therapy for hepatitis B and C are effective for primary prevention of virus-related HCCs, but chemoprevention strategies for non-viral liver disease remain an unmet need. Emerging data suggest associations between aspirin, statins, metformin and coffee and reduced HCC incidence, although none has been proved to be causally related. Secondary prevention of HCC via semi-annual surveillance is associated with improvements in early detection and thus reduced mortality; however, current tools, including abdominal ultrasonography, have suboptimal sensitivity for the detection of early stage HCC, particularly in patients with obesity and/or non-viral liver disease. Promising blood-based or imaging-based surveillance strategies are emerging, although these approaches require further validation before adoption in clinical practice. In the interim, efforts should be focused on maximizing use of the existing surveillance tools given their prevalent underuse globally. Remarkable advances have been made in the treatment of HCC, including expanded eligibility for surgical therapies, improved patient selection for locoregional treatments and increased systemic treatment options, including immune-checkpoint inhibitors. In this Review, we discuss trends in the epidemiology of HCC and their implications for screening, prevention and therapy.

Screening of liver cancer with abbreviated MRI

Current recommendations for the surveillance of HCC are based on the semiannual liver ultrasound (with or without serum alpha-fetoprotein) in patients with cirrhosis and in subgroups with chronic hepatitis B infection. However, the sensitivity of this strategy is suboptimal for the detection of early-stage tumors, especially in obese patients, due to interoperator variability and poor adherence. The detection rate of focal liver lesions is excellent with MRI, making it the best alternative candidate for surveillance. However, performing a full contrast-enhanced MRI is unrealistic because of limited availability and health economics. Abbreviated MRI (AMRI) corresponds to the acquisition of a limited number of sequences with a high detection rate. The theoretical benefits of AMRI are a reduced acquisition time (≤10 min) with improved time-effectiveness and cost-effectiveness compared with conventional MRI, and greater accuracy than ultrasound. Numerous protocols may be performed, including T1-weighted, T2-weighted, and DWI sequences, with or without contrast administration. Although published studies report promising per-patient results, they should be interpreted with caution. Indeed, most studies were simulated, retrospectively reviewing a subset of sequences in relatively small populations who underwent a full MRI. They also included groups that were not representative of screening populations. In addition, most were published by Asian groups, with at-risk populations that were different from Western populations. There are no existing longitudinal studies that directly compare the different AMRI approaches or AMRI to ultrasound. Finally, it is possible that 1 approach will not fit all patients and that strategies should be tailored to the risk of HCC, in particular in relation to the cost and availability of AMRI. Several trials are ongoing to evaluate these questions.

International Liver Cancer Association (ILCA) white paper on hepatocellular carcinoma risk stratification and surveillance

Major research efforts in liver cancer have been devoted to increasing the efficacy and effectiveness of surveillance for hepatocellular carcinoma (HCC). As with other cancers, surveillance programmes aim to detect tumours at an early stage, facilitate curative-intent treatment, and reduce cancer-related mortality. HCC surveillance is supported by a large randomised-controlled trial in patients with chronic HBV infection and several cohort studies in cirrhosis; however, effectiveness in clinical practice is limited by several barriers, including inadequate risk stratification, underuse of surveillance, and suboptimal accuracy of screening tests. There are several proposed strategies to address these limitations, including risk stratification algorithms and biomarkers to better identity at-risk individuals, interventions to increase surveillance, and emerging imaging- and blood-based surveillance tests with improved sensitivity and specificity for early HCC detection. Beyond clinical validation, data are needed to establish clinical utility, i.e. increased early tumour detection and reduced HCC-related mortality. If successful, these data could facilitate a precision screening paradigm in which surveillance strategies are tailored to individual HCC risk to maximise overall surveillance value. However, practical and logistical considerations must be considered when designing and implementing these validation efforts. To address these issues, ILCA (the International Liver Cancer Association) adjourned a single topic workshop on HCC risk stratification and surveillance in June 2022. Herein, we present a white paper on these topics, including the status of the field, ongoing research efforts, and barriers to the translation of emerging strategies.

Quality Assessment of Ultrasound and Magnetic Resonance Imaging for Hepatocellular Carcinoma Surveillance: A Systematic Review and Meta-Analysis

INTRODUCTION

To achieve early detection and curative treatment options, surveillance imaging for hepatocellular carcinoma (HCC) must remain of quality and without substantial limitations in liver visualization. However, the prevalence of limited liver visualization during HCC surveillance imaging has not been systematically assessed. Utilizing a systematic review and meta-analytic approach, we aimed to determine the prevalence of limited liver visualization during HCC surveillance imaging.

METHODS

MEDLINE and Embase electronic databases were searched to identify published data on liver visualization limitations of HCC surveillance imaging. An analysis of proportions was pooled using a generalized linear mixed model with Clopper-Pearson intervals. Risk factors were analysed using a generalized mixed model with a logit link and inverse variance weightage.

RESULTS

Of 683 records, 10 studies (7,131 patients) met inclusion criteria. Seven studies provided data on liver visualization limitations on ultrasound (US) surveillance exams: prevalence of limited liver visualization was 48.9% (95% CI: 23.5-74.9%) in the overall analysis and 59.2% (95% CI: 24.2-86.9%) in a sensitivity analysis for cirrhotic patients. Meta-regression determined that non-alcoholic fatty liver disease was associated with limited liver visualization on US. Four studies provided data for liver visualization limitations in abbreviated magnetic resonance imaging (aMRI), with inadequate visualization ranging from 5.8% to 19.0%. One study provided data for complete MRI and none for computed tomography.

CONCLUSION

A substantial proportion of US exams performed for HCC surveillance provide limited liver visualization, especially in cirrhosis, which may hinder detection of small observations. Alternative surveillance strategies including aMRI may be appropriate for patients with limited US visualization.

Opportunities to address gaps in early detection and improve outcomes of liver cancer

Death rates from primary liver cancer (hepatocellular carcinoma [HCC]) have continued to rise in the United States over the recent decades despite the availability of an increasing range of treatment modalities, including new systemic therapies. Prognosis is strongly associated with tumor stage at diagnosis; however, most cases of HCC are diagnosed beyond an early stage. This lack of early detection has contributed to low survival rates. Professional society guidelines recommend semiannual ultrasound-based HCC screening for at-risk populations, yet HCC surveillance continues to be underused in clinical practice. On April 28, 2022, the Hepatitis B Foundation convened a workshop to discuss the most pressing challenges and barriers to early HCC detection and the need to better leverage existing and emerging tools and technologies that could improve HCC screening and early detection. In this commentary, we summarize technical, patient-level, provider-level, and system-level challenges and opportunities to improve processes and outcomes across the HCC screening continuum. We highlight promising approaches to HCC risk stratification and screening, including new biomarkers, advanced imaging incorporating artificial intelligence, and algorithms for risk stratification. Workshop participants emphasized that action to improve early detection and reduce HCC mortality is urgently needed, noting concern that many of the challenges we face today are the same or similar to those faced a decade ago and that HCC mortality rates have not meaningfully improved. Increasing the uptake of HCC screening was identified as a short-term priority while developing and validating better screening tests and risk-appropriate surveillance strategies.

Prediagnostic CT or MRI Utilization and Outcomes in Hepatocellular Carcinoma: SEER-Medicare Database Analysis

Ultrasound-based surveillance has suboptimal sensitivity for early hepatocellular carcinoma (HCC) detection, generating interest in alternative surveillance modalities. We aim to investigate the association between prediagnostic CT or MRI and overall survival in a contemporary cohort of patients with HCC. Using the Surveillance Epidemiology and End Results (SEER)-Medicare database, we analyzed Medicare beneficiaries diagnosed with HCC between 2011 and 2015. Proportion of time covered (PTC) was defined as the proportion of the 36-month period prior to HCC diagnosis in which patients had received abdominal imaging (ultrasound, CT, MRI). Cox proportional hazards regression was used to investigate the association between PTC and overall survival. Among 5,098 patients with HCC, 3,293 (65%) patients had abdominal imaging prior to HCC diagnosis, of whom 67% had CT/MRI. Median PTC by any abdominal imaging was 5.6% [interquartile range (IQR): 0%-36%], with few patients having PTC >50%. Compared with no abdominal images, ultrasound [adjusted HR (aHR): 0.87, 95% confidence interval (CI): 0.79-0.95] and CT/MRI group (aHR: 0.68, 95% CI: 0.63-0.74) were associated with improved survival. Lead-time adjusted analysis showed improved survival continued to be observed with CT/MRI (aHR: 0.80, 95% CI: 0.74-0.87) but not ultrasound (aHR: 1.00, 95% CI: 0.91-1.10). Increased PTC was associated with improved survival, with a larger effect size observed with CT/MRI (aHR per 10%: 0.93, 95% CI: 0.91-0.95) than ultrasound (aHR per 10%: 0.96, 95% CI: 0.95-0.98). In conclusion, PTC by abdominal images was associated with improved survival in patients with HCC, with potential greater benefit using CT/MRI. Regular utilization of CT/MRI before cancer diagnosis may have potential survival benefit compared to ultrasound in patients with HCC.

Significance

Our population-based study using SEER-Medicare database demonstrated that proportion of time covered by abdominal imaging was associated with improved survival in patients with HCC, with potential greater benefit using CT/MRI. The results suggest that CT/MRI surveillance may have potential survival benefit compared with ultrasound surveillance in high-risk patients for HCC. A larger prospective study should be conducted for external validation.

Multicenter Validation of Abbreviated MRI for Detecting Early-Stage Hepatocellular Carcinoma

Background Abbreviated MRI is a proposed paradigm shift for hepatocellular carcinoma (HCC) surveillance, but data on its performance are lacking for histopathologically confirmed early-stage HCC. Purpose To evaluate the sensitivity and specificity of dynamic contrast-enhanced abbreviated MRI for early-stage HCC detection, using surgical pathologic findings as the reference standard. Materials and Methods This retrospective study was conducted at three U.S. liver transplant centers in patients with cirrhosis who underwent liver resection or transplant between January 2009 and December 2019 and standard "full" liver MRI with and without contrast enhancement within 3 months before surgery. Patients who had HCC-directed treatment before surgery were excluded. Dynamic abbreviated MRI examinations were simulated from the presurgical full MRI by selecting the coronal T2-weighted and axial three-dimensional fat-suppressed T1-weighted dynamic contrast-enhanced sequences at precontrast, late arterial, portal venous, and delayed phases. Two abdominal radiologists at each center independently interpreted the simulated abbreviated examinations with use of the Liver Imaging Reporting and Data System version 2018. Patients with any high-risk liver observations (>LR-3) were classified as positive; otherwise, they were classified as negative. With liver pathologic findings as the reference standard for the presence versus absence of early-stage HCC, the sensitivity, specificity, and their 95% CIs were calculated. Logistic regression was used to identify factors associated with correct classification. Results A total of 161 patients with early-stage HCC (median age, 62 years [IQR, 58-67 years]; 123 men) and 138 patients without HCC (median age, 55 years [IQR, 47-63 years]; 85 men) were confirmed with surgical pathologic findings. The sensitivity and specificity of abbreviated MRI were 88.2% (142 of 161 patients) (95% CI: 83.5, 92.5) and 89.1% (123 of 138 patients) (95% CI: 84.4, 93.8), respectively. Sensitivity was lower for Child-Pugh class B or C versus Child-Pugh class A cirrhosis (64.1% vs 94.2%; P < .001). Conclusion With surgical pathologic findings as the reference standard, dynamic abbreviated MRI had high sensitivity and specificity for early-stage hepatocellular carcinoma detection in patients with compensated cirrhosis but lower sensitivity in those with decompensated cirrhosis. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Kim in this issue.

Non-alcoholic fatty liver disease-related hepatocellular carcinoma

Non-alcoholic fatty liver disease (NAFLD), one of the most common causes of liver disease, is an increasingly common cause of hepatocellular carcinoma (HCC). Several demographic, clinical, and genetic factors contribute to HCC risk in NAFLD patients, which may inform risk stratification scores. Proven efficacious approaches to primary prevention approach in patients with non-viral liver disease remain an area of need. Semi-annual surveillance is associated with improved early tumor detection and reduced HCC-related mortality; however, patients with NAFLD have several challenges to effective surveillance, including under-recognition of at-risk patients, low surveillance utilization in clinical practice, and lower sensitivity of current tools for early-stage HCC detection. Treatment decisions are best made in a multidisciplinary fashion and are informed by several factors including tumor burden, liver dysfunction, performance status, and patient preferences. Although patients with NAFLD often have larger tumor burden and increased comorbidities compared to counterparts, they can achieve similar post-treatment survival with careful patient selection. Therefore, surgical therapies continue to provide a curative treatment option for patients diagnosed at an early stage. Although there has been debate about the efficacy of immune checkpoint inhibitors in patients with NAFLD, current data are insufficient to change treatment selection based on liver disease etiology.

Hepatocellular carcinoma surveillance in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) may progress to cirrhotic or non-cirrhotic hepatocellular carcinoma (HCC), and is currently recognized as the fastest growing cause of HCC worldwide. Accordingly, professional society guidelines recommend HCC surveillance in patients with cirrhosis from any etiology, and some may consider it beneficial in subgroups with non-cirrhotic NAFLD at higher risk for HCC. Notably, patients with NAFLD-related HCC are more likely to have HCC diagnosed at more advanced stages and have poorer outcomes when compared to other etiologies, and suboptimal effectiveness of HCC surveillance programs is a major culprit. In this review, we summarize the current guidelines for HCC surveillance and discuss its benefits versus potential harms for NAFLD patients. We also address the unique challenges of HCC surveillance in NAFLD, including higher proportion of NAFLD-related HCC without cirrhosis, poor recognition of at-risk patients, lack of consensus regarding the value of surveillance in non-cirrhotic NAFLD, subpar effectiveness of surveillance tools related to NAFLD phenotype, and preponderant surveillance underuse among NAFLD patients. Finally, we examine the effectiveness of currently used surveillance tools (i.e., ultrasound and alpha fetoprotein) and outline future perspectives including emerging risk stratification tools, imaging surveillance strategies (e.g., abbreviated magnetic resonance imaging protocols), blood-based biomarkers (e.g., GALAD and circulating tumor DNA panels), and interventions to improve surveillance adherence.

Emerging Tools for Hepatocellular Carcinoma Surveillance

Abdominal ultrasound, with or without alpha-fetoprotein, is the recommended strategy for hepatocellular carcinoma (HCC) surveillance but misses over one-third of HCC at an early stage. Emerging imaging modalities, including computed tomography and magnetic resonance imaging, have early data showing high sensitivity for early-stage HCC, but potential issues such as radiologic capacity, patient acceptance, cost-effectiveness, and need for validation in Western non-hepatitis B virus populations still need to be evaluated. Similarly, blood-based biomarker panels, including GALAD and liquid biopsy techniques, have shown promising data in phase II case-control studies and may concurrently help address issues of surveillance underuse; however, these tools require validation in phase III and IV cohort studies. While awaiting prospective validation data for these emerging strategies, ultrasound with or without alpha-fetoprotein remains the current gold standard HCC surveillance strategy.

Early detection of hepatocellular carcinoma: roadmap for improvement

INTRODUCTION

Hepatocellular carcinoma (HCC) has a poor prognosis, related, in part, to frequent late-stage diagnosis. Improved implementation of effective HCC surveillance is critical to reduce HCC mortality.

AREAS COVERED

We performed a targeted literature review to identify intervention targets for improving HCC surveillance effectiveness, including enriched risk stratification tools, improved surveillance tools with higher accuracy for early HCC detection, and increasing surveillance adherence.

EXPERT OPINION

HCC surveillance has been demonstrated to be efficacious in several cohort studies but has lower surveillance effectiveness in clinical practice. HCC surveillance is currently recommended in all patients with cirrhosis, and improved risk stratification using clinical risk scores, genetic scores, and novel biomarkers are important to move from a 'one-size-fits-all' strategy to one more aligned with values of precision medicine. Current surveillance modalities, ultrasound, and AFP, miss over one-third of HCC at an early stage and are associated with potential surveillance harms, underscoring a need for alternative surveillance strategies with higher accuracy. MRI- and biomarker-based surveillance strategies have promising early data in phase II studies but require validation in phase III cohorts before routine use in practice. Finally, surveillance is underused in clinical practice, highlighting a need for intervention strategies to increase utilization.

Comparative efficacy of an optimal exam between ultrasound versus abbreviated MRI for HCC screening in NAFLD cirrhosis: A prospective study

BACKGROUND

Retrospective studies report that visualisation of the liver may be severely limited using ultrasound (US), potentially contributing to diminished sensitivity for detection of hepatocellular carcinoma (HCC) among patients with nonalcoholic fatty liver disease (NAFLD) and cirrhosis, but there are limited prospective data.

AIMS

To compare liver visualisation scores prospectively for US and abbreviated hepatobiliary phase (HBP) magnetic resonance imaging (AMRI) in a cohort of participants with NAFLD cirrhosis and a clinical indication for HCC surveillance.

METHODS

This prospective multicenter study included 54 consecutive participants (67% women) with NAFLD cirrhosis who underwent contemporaneous US as well as HBP-AMRI with gadoxetic acid. Primary outcome was the proportion of imaging examinations with severe limitations in liver visualisation (visualisation score C) compared head-to-head between US and AMRI.

RESULTS

The mean (± standard deviation) age was 63.3 years (±8.4) and body mass index was 32.0 kg/m2 (±6.0). Nineteen participants (35%) had severe visualisation limitations on US, compared with 10 (19%) with AMRI, p < 0.0001. Nine (17%) participants had <90% of the liver visualised on US, compared with only 1 (2%) participant with AMRI, p < 0.0001. Obesity was a strong and independent predictor for severe visualisation limitation on US (OR 5.1, CI 1.1-23.1, p = 0.03), after adjustment for age, sex and ethnicity.

CONCLUSION

More than one-third of participants with NAFLD cirrhosis had severe visualisation limitations on US for HCC screening, compared with one-sixth on AMRI. US adequacy should be reported in all clinical studies and when suboptimal then AMRI may be considered for HCC screening.

Hypervascular transformation of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement on gadoxetic acid-enhanced MRI: long-term follow-up in a surveillance cohort

OBJECTIVES

With the increasing use of gadoxetic acid-enhanced MRI for HCC surveillance, hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) are frequently encountered. We investigated the rate of these nodules with hypervascular transformation, which suggests hepatocarcinogenesis, by using a prospectively collected longitudinal surveillance cohort data.

METHODS

This study included 382 prospectively enrolled patients at high risk for developing HCC who underwent 1-3 rounds of bi-annual surveillance gadoxetic acid-enhanced MRI. MRI was analyzed to detect HBP hypointense nodules without APHE. Follow-up dynamic CTs and MRIs were evaluated to detect hypervascular transformation of the nodules. Cox proportional hazards regression analyses were used to find predictors for hypervascular transformation.

RESULTS

A total of 76 HBP hypointense nodules without APHE were found in 48 patients, giving a prevalence of 12.6% (48/382). The mean nodule size was 10.8 mm, with 43.4% (33/76) being ≥ 10 mm. Over a median follow-up of 78.6 months, 19 nodules (25.0%) showed hypervascular transformation, all of which demonstrated typical imaging features of HCC. On multivariable Cox-regression analysis, size (≥ 10 mm) was the only independent predictor of hypervascular transformation (hazard ratio, 3.31; 95% confidence interval, 1.21-9.05). The cumulative incidence of hypervascular transformation at 12 and 60 months of nodules ≥ 10 mm was 12.3% and 50.4%, respectively, while that of nodules < 10 mm was 2.5% and 13.9%, respectively.

CONCLUSIONS

About half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC at 5 years of follow-up, indicating the necessity for cautious monitoring with an augmented and extended follow-up schedule for these nodules.

KEY POINTS

• The prevalence of HBP hypointense nodules without APHE was 12.6% in a prospectively recruited population at high risk of developing HCC. • Nodule size ≥ 10 mm was significantly associated with hypervascular transformation, and approximately half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC during 5 years of follow-up. • Given the risk of malignant transformation, HBP hypointense nodules ≥ 10 mm without APHE should be closely monitored.