Fluorine-18 fluorodeoxyglucose positron emission tomography predicts tumor differentiation, P-glycoprotein expression, and outcome after resection in hepatocellular carcinoma

Quarter-Century PET/Computed Tomography Transformation of Oncology: Hepatobiliary and Pancreatic Cancer

[18F] Fluorodeoxyglucose (18F-FDG) PET/CT can improve the staging accuracy and clinical management of patients with hepatobiliary and pancreatic cancers, by detection of unsuspected metastases. 18F-FDG PET/CT metabolic parameters are valuable in predicting treatment response and survival. Metabolic response on 18F-FDG PET/CT can predict preoperative pathologic response to neoadjuvant therapy in patients with pancreatic cancer and determine prognosis. Several novel non-FDG tracers, such as 68Ga prostate-specific membrane antigen (PSMA) and 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT, show promise for imaging hepatobiliary and pancreatic cancers with potential for radioligand therapy.

A fingerprint of 2-[18F]FDG radiometabolites - How tissue-specific metabolism beyond 2-[18F]FDG-6-P could affect tracer accumulation

Studies indicate that the radiotracer 2-[18F]fluoro-2-deoxy-D-glucose (2-[18F]FDG) can be metabolized beyond 2-[18F]FDG-6-phosphate (2-[18F]FDG-6-P), but its metabolism is incompletely understood. Most importantly, it remains unclear whether downstream metabolism affects tracer accumulation in vivo. Here we present a fingerprint of 2-[18F]FDG radiometabolites over time in cancer cells, corresponding tumor xenografts and murine organs. Strikingly, radiometabolites representing glycogen metabolism or the oxPPP correlated inversely with tracer accumulation across all examined tissues. Recent studies suggest that not only hexokinase, but also hexose-6-phosphate dehydrogenase (H6PD), an enzyme of the oxidative pentose phosphate pathway (oxPPP), determines 2-[18F]FDG accumulation. However, little is known about the corresponding enzyme glucose-6-phosphate dehydrogenase (G6PD). Our mechanistic in vitro experiments on the role of the oxPPP propose that 2-[18F]FDG can be metabolized via both G6PD and H6PD, but data from separate enzyme knockdown suggest diverging roles in downstream tracer metabolism. Overall, we propose that tissue-specific metabolism beyond 2-[18F]FDG-6-P could matter for imaging.

Achievement of Complete Response and Drug-Free Status by Atezolizumab plus Bevacizumab Combined with or without Curative Conversion in Patients with Transarterial Chemoembolization-Unsuitable, Intermediate-Stage Hepatocellular Carcinoma: A Multicenter Proof-Of-Concept Study

Introduction

Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. When tumor shrinkage is obtained, achieving complete response (CR) is possible in many cases using curative conversion with resection, ablation, or superselective transarterial chemoembolization (TACE) with curative intent. This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter proof-of-concept study was conducted to show the value of curative conversion in immunotherapy-treated intermediate-stage HCC meeting TACE-unsuitable criteria.

Methods

This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. CR rate, drug-free rate, time to CR, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, progression-free survival (PFS), and overall survival (OS) were assessed in patients who achieved CR using resection, ablation, superselective TACE with curative intent following atezolizumab plus bevacizumab or atezolizumab plus bevacizumab alone.

Results

Clinical or pathological CR was achieved in 38 patients (35%) (median observation period: 21.2 months). The modalities of curative conversion in 35 patients were as follows: resection, 7; ablation, 13; and superselective TACE, 15. Three patients achieved clinical CR with atezolizumab plus bevacizumab therapy alone. Among the 38 CR patients, 25 achieved drug-free status. PFS was not reached, and 3 patients experienced recurrence after reaching CR. Regarding OS, there were no deaths in any of the CR patients. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved CR with atezolizumab plus bevacizumab followed by curative conversion, five achieved drug-free status.

Conclusion

The achievement of CR rate by curative conversion in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 23% of patients achieved drug-free status and no recurrence was observed from this patient subgroup with CR and drug-free status. Thus, achieving CR and/or drug-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread.

Predicting Outcomes of Atezolizumab and Bevacizumab Treatment in Patients with Hepatocellular Carcinoma

A combination of atezolizumab with bevacizumab (AB) is the first regimen that has shown superiority compared to sorafenib and is now being used as the systemic treatment of choice for hepatocellular carcinoma (HCC) patients with Barcelona Liver Cancer Clinic stage C. However, a considerable number of patients do not achieve survival or significant responses, indicating the need to identify predictive biomarkers for initial and on-treatment decisions in HCC patients receiving AB. In this manuscript, we summarized the current data from both experimental and clinical studies. This review will be beneficial for both clinicians and researchers in clinical practice as well as those designing experimental, translational, or clinical studies.

Impact of metabolic indices of 18F-fluorodeoxyglucose positron emission tomography/computed tomography on post transplantation recurrence of hepatocellular carcinoma

BACKGROUND

Tumor recurrence is the leading cause of death after liver transplantation in patients with hepatocellular carcinoma. There is an ongoing debate as to whether metabolic indices such as tumor to liver standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography of the primary tumor can identify patients outside the Milan criteria with as low recurrence rates as patients inside Milan and thus should be added to the established prognostic factors.

METHODS

This retrospective study analyzes 103 consecutive patients who underwent ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography before liver transplantation for hepatocellular carcinoma using data of clinical tumor registry. Primary endpoints were overall survival and 10-year cumulative recurrence rates.

RESULTS

Tumor to liver standardized uptake value ratio of the primary tumor was statistically significant higher in Milan out tumors, "up-to-seven" out tumors, grade 3 tumors, α- fetoprotein level >400 ng/ml and lesions > 5cm in diameter. Factors with statistically significant influence on the 10- year overall survival in the univariate analysis were Milan, up-to-seven" criteria, number of lesions and pT-category. COX regression analysis did not show independently statistically significant factors for 10-year overall survival. Milan, "up-to-seven" criteria, grade, pV, number of lesions, size of lesion, pT-category, tumor to liver standardized uptake value ratio influenced 10-year cumulative recurrence rates statistically significant. Tumor to liver standardized uptake value ratio, grade and pT-category proved to be independently statistically significant factors for 10-year cumulative recurrence rates.

CONCLUSIONS

Our study suggests that tumor to liver standardized uptake value standardized uptake value ratio in ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography is an independent prognostic factor in transplanted patients with hepatocellular carcinoma. If we focus on preoperative findings, such as tumor size, tumor number and AFP value adding the information given by TLR of ¹⁸F-FDG PET/CT allows to estimate the risk of tumor recurrence more accurate than the established classifications Milan and UTS. Therefore, it may add valuable information to other preoperative findings, such as tumor size, tumor number and AFP level.

Advances in Immunotherapy for Hepatocellular Carcinoma

Immune checkpoint inhibitors (ICIs) aim to induce immune responses against tumors and are less likely to develop drug resistance than molecularly targeted drugs. In addition, they are characterized by a long-lasting antitumor effect. However, since its effectiveness depends on the tumor’s immune environment, it is essential to understand the immune environment of hepatocellular carcinoma to select ICI therapeutic indications and develop biomarkers. A network of diverse cellular and humoral factors establishes cancer immunity. By analyzing individual cases and classifying them from the viewpoint of tumor immunity, attempts have been made to select the optimal therapeutic drug for immunotherapy, including ICIs. ICI treatment is discussed from the viewpoints of immune subclass of HCC, Wnt/β-catenin mutation, immunotherapy in NASH-related HCC, the mechanism of HPD onset, and HBV reactivation.

Liver Transplantation for Hepatocellular Carcinoma: How Should We Improve the Thresholds?

Simple Summary

The ideal treatment for hepatocellular carcinoma (HCC) is liver transplantation (LT), which both eliminates the HCC and cures the diseased liver. Once considered an experimental treatment with dismal survival rates, LT for HCC entered a new era with the establishment of the Milan criteria over 20 years ago. However, over the last two decades, the Milan criteria, which are based on tumor morphology, have come under intense scrutiny and are now largely regarded as too restrictive, and limit the access of transplantation for many patients who would otherwise achieve good clinical outcomes. The liver transplant community has been making every effort to reach a goal of establishing more reliable selection criteria. This article addresses how the criteria have been extended, as well as the concept of pre-transplant down-staging to maximize the eligibility.

Abstract

Hepatocellular carcinoma (HCC) is the third highest cause of cancer-related mortality, and liver transplantation is the ideal treatment for this disease. The Milan criteria provided the opportunity for HCC patients to undergo LT with favorable outcomes and have been the international gold standard and benchmark. With the accumulation of data, however, the Milan criteria are not regarded as too restrictive. After the implementation of the Milan criteria, many extended criteria have been proposed, which increases the limitations regarding the morphological tumor burden, and incorporates the tumor’s biological behavior using surrogate markers. The paradigm for the patient selection for LT appears to be shifting from morphologic criteria to a combination of biologic, histologic, and morphologic criteria, and to the establishment of a model for predicting post-transplant recurrence and outcomes. This review article aims to characterize the various patient selection criteria for LT, with reference to several surrogate markers for the biological behavior of HCC (e.g., AFP, PIVKA-II, NLR, 18F-FDG PET/CT, liquid biopsy), and the response to locoregional therapy. Furthermore, the allocation rules in each country and the present evidence on the role of down-staging large tumors are addressed.

Diagnostic and prognostic impact of fluorodeoxyglucose-positron emission tomography in diagnosing intraductal papillary neoplasms of the bile duct of the liver

Purpose

Malignant intraductal papillary neoplasm of the bile duct of the liver (IPNB-L) cannot readily be diagnosed through preoperative CT or MRI, but fluorodeoxyglucose (FDG)-PET is a viable alternative. This study evaluated the diagnostic and prognostic impacts of FDG-PET in patients with IPNB-L.

Methods

This was a retrospective single-center study of 101 IPNB-L patients who underwent hepatectomy between 2010 and 2019.

Results

Mean age was 64.4 ± 8.3 years and 76 (75.2%) were male. Anatomical hepatic resection was performed in 99 (98.0%). Concurrent bile duct resection and pancreaticoduodenectomy were performed in 41 (40.6%) and 1 (1.0%), respectively. R0 and R1 resections were performed in 88 (87.1%) and 13 (12.9%), respectively. Low-grade intraepithelial neoplasia and high-grade neoplasia/invasive carcinoma were diagnosed in 19 (18.8%) and 82 (81.2%), respectively. Median FDG-PET maximal standardized uptake values (SUVmax) in low-grade neoplasia and high-grade neoplasia/carcinoma were 3.6 (range, 1.7–7.6) and 5.2 (range, 1.5–18.7) (P = 0.019), respectively. Receiver operating characteristic curve analysis of SUVmax showed area under the curve of 0.674, with sensitivity of 84.2% and specificity of 47.4% at SUVmax cutoff of 3.0. This cutoff had no significant influence on tumor recurrence (P = 0.832) or patient survival (P = 0.996) in patients with IPNB-L of high-grade neoplasia or invasive carcinoma.

Conclusion

IPNB-L is a rare type of biliary neoplasm and encompasses a histological spectrum ranging from benign disease to invasive carcinoma. An FDG-PET SUVmax cutoff of 3.0 appears to effectively discern high-grade neoplasia/carcinoma from low-grade neoplasia, which will assist with the surgical strategy for these cases.

Prospect of lenvatinib for unresectable hepatocellular carcinoma in the new era of systemic chemotherapy

The phase III clinical trial of the novel molecular targeted agent (MTA) lenvatinib for patients with advanced hepatocellular carcinoma (HCC) (REFLECT trial) found that lenvatinib was non-inferior to sorafenib in overall survival. Recently, the efficacy of multiple MTAs, including lenvatinib, in practice has been reported, and therapeutic strategies for Barcelona Clinic Liver Cancer (BCLC) intermediate stage HCC are undergoing major changes. Based on these results, lenvatinib could be recommended for patients with transcatheter arterial chemoembolization (TACE)-refractory, ALBI grade 1, within the up-to-seven criteria in the BCLC intermediate stage. Lenvatinib provides a more favorable outcome than TACE, even in cases with large or multinodular HCC beyond the up-to-seven criteria with Child-Pugh grade A. When patients meet the definitions of TACE-refractory or TACE-unsuitable, switching to systemic chemotherapy, including lenvatinib, is for favorable for preserving liver function. If initial treatment, including MTA, has a significant therapeutic effect and downstaging of HCC is obtained, additional TACE or surgical resection should be considered. Lenvatinib also has a therapeutic effect for poorly differentiated type and non-simple nodular type HCC thanks to the survival-prolonging effect of this drug. Furthermore, a significant therapeutic effect is expected in tumors with more than 50% liver involvement or main portal vein invasion, which have traditionally been considered to have a poor prognosis in patients. This suggests that at the start of lenvatinib treatment, HCC patients with ALBI grade 1 may be able to maintain liver functional reserve.

Identifying Patients Who May Benefit from Liver Resection Compared to Living Donor Liver Transplantation for Hepatocellular Carcinoma Using 18F-FDG PET

BACKGROUND

This study aimed to assess an oncologic setting where patients with hepatocellular carcinoma (HCC) could benefit from liver resection (LR) compared to living donor liver transplantation (LDLT) using ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography.

METHODS

The consecutive data of patients with HCC who underwent ¹⁸F-FDG PET before LR (LR group, n = 314) and LDLT (LDLT group, n = 65) between 2003 and 2015 were retrospectively analyzed. Tumor ¹⁸F-FDG avidity was quantified as the tumor to liver standardized uptake value ratio (TLR, cut-off value was defined at 2). Multivariate analysis was performed to assess significant preoperative tumor factors in the LR group. Survival outcomes between the two groups were stratified by these factors.

RESULTS

The 5-year overall survival (OS: 56.9% vs. 73.8%, LR vs. LDLT, p < 0.001) and recurrence-free survival rate (RFS: 27.4% vs. 70.7%, p < 0.001) were significantly better in the LDLT group compared to the LR group. In the LR study, multivariate analysis identified TLR and tumor multiplicity as significant preoperative tumor factors for OS. In patients with solitary and TLR < 2 HCC, the 5-year OS rate was not significantly different between the LR and LDLT groups (70.3% vs. 71.8%, p = 0.352); meanwhile, RFS rate was better in the LDLT group (34.3% vs. 71.8%, p = 0.001).

CONCLUSIONS

LDLT is associated with better long-term outcomes than LR in patients with HCC; however, selected patients with solitary and TLR < 2 HCC may benefit from LR.

Quantitative assessment of microvascular invasion in hepatocellular carcinoma using preoperative serological and imaging markers

BACKGROUND

The aim of this study was to establish a quantitative equation to predict microvascular invasion (MVI) for patients with resectable hepatocellular carcinoma (HCC).

METHODS

This retrospective study included 219 patients with resected HCC from 2004 to 2015. All had available three pre-operative serological markers (alfa-feto protein (AFP), fucosylated AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP)), and one imaging marker (tumor to liver ratio of SUVmax (TLR) by ¹⁸F-FDG-PET). A multiple linear regression model for predicting MVI was developed (2004-2009, n = 111) and then validated (2010-2015, n = 108). Further, impact on the obtained model on survival outcomes was assessed.

RESULTS

Using the derivation cohort, following equation was developed; MVI probability (%) = 14.2 × log₁₀DCP + 9.9 × TLR - 22.0. This model resulted in an area under receiver operating characteristic curve (ROC) of 0.806 and 0.751, in the derivation and validation cohort, respectively. Furthermore, MVI probability ≥40% determined by ROC analysis was associated with worse overall survival and recurrence-free survival in the derivation and the validation cohort (all p < 0.05).

CONCLUSION

A quantitative model, using DCP and TLR, was able to preoperatively predict with good performance MVI and long-term outcomes in patients with HCC after liver resection.

Diagnostic test accuracies of F-18 FDG PET/CT for prediction of microvascular invasion of hepatocellular carcinoma: A meta-analysis

PURPOSE

The aim of the current meta-analysis was to evaluate diagnostic accuracies of preoperative F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) or positron emission tomography/computed tomography (PET/CT) for prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients.

METHODS

The scientific database such as PubMed, Cochrane, and Embase database were searched for studies evaluating diagnostic accuracies of preoperative F-18 FDG PET or PET/CT for prediction of MVI in HCC patients up to November 30, 2020.

RESULTS

Fourteen eligible studies (1276 patients) were enrolled. The pooled sensitivity for F-18 FDG PET or PET/CT was 0.67 (95% CI; 0.57-0.76) with heterogeneity and a pooled specificity of 0.80 (95% CI; 0.74-0.85) with heterogeneity. Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 3.3 (95% CI; 2.5-4.5) and negative likelihood ratio (LR-) of 0.41 (95% CI; 0.31-0.55). The pooled diagnostic odds ratio (DOR) was 8 (95% CI; 5-14). Summary receiver operating characteristic (ROC) curve indicates that the area under the curve was 0.81 (95% CI; 0.78-0.84).

CONCLUSION

The current meta-analysis showed a low sensitivity and moderate specificity of F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients. F-18 FDG PET or PET/CT might not be useful for the preoperative prediction of MVI in HCC patients and should not be used to exclude MVI. Therefore, cautious application and interpretation should be paid to the F-18 FDG PET or PET/CT for the prediction of MVI in HCC patients preoperatively.

Pretreatment Positron Emission Tomography with 18F-Fluorodeoxyglucose May Be a Useful New Predictor of Overall Prognosis Following Lenvatinib Treatment

BACKGROUND AND AIM

The aim of this study was to identify the utility of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) as a predictor of overall prognosis in patients with hepatocellular carcinoma treated with lenvatinib.

METHODS

Forty-eight consecutive patients who received lenvatinib treatment were reviewed. The oncological aggressiveness of tumors estimated using 18F-FDG-PET/CT was investigated by the analysis of progression-free survival (PFS), post-progression survival (PPS), and overall survival (OS). Multivariate analysis was used to identify potential confounders for OS during lenvatinib therapy.

RESULTS

Using the Modified Response Evaluation Criteria in Solid Tumors, a tumor-to-normal liver ratio (TLR) ≥2, indicating higher oncological aggressiveness in HCCs, was associated with a better objective response to lenvatinib than a TLR <2 (78 vs. 62%), resulting in a similar PFS (p = 0.751). Because of a significantly worse PPS, OS with a TLR ≥2 was poor compared to a TLR < 2 (p = 0.012). Multivariate analysis confirmed that a TLR ≥ 2 was associated with poor OS (hazard ratio, 2.709; 95% CI, 1.140-6.436; p = 0.024). Analysis of 24 patients who received a repeat 18F-FDG-PET/CT showed that daily changes expressed as ΔTLR × 103/day over the treatment course tended to be different among the types of subsequent treatment. A R0 resection and lenvatinib-TACE sequential therapy provided good disease control (median, -4.593 and -0.024, respectively) compared with other treatments (median, 5.278) (p = 0.075).

CONCLUSION

Lenvatinib has acceptable disease control regardless of estimated tumor differentiation. A high TLR (≥2) is a poor prognostic factor of OS following lenvatinib treatment, while ΔTLR × 103/day provides useful information of disease control status.

Extrahepatic metastases from hepatocellular carcinoma: multimodality image evaluation

The most prevalent primary malignancy of the liver is hepatocellular carcinoma (HCC); its poor prognosis is mainly related to intrahepatic recurrence and extrahepatic metastases. However, survival from HCC has improved due to better control of the primary tumor, the development of newer treatment modalities, including liver transplant, together with advances in imaging techniques. Therefore, the significance of patient management as corresponds with distant metastases has increased; since the proper evaluation and detection of extrahepatic metastases is crucial to optimize potential therapy for patients. Conventional imaging like CT, MRI play crucial rule in patient's diagnosis and qualifying for a certain type of therapy. More recently, a molecular imaging tool with radiolabeled deoxyglucose and fluorocholine has proved its promising value as a complementary tool to conventional studies. In this review, the frequent sites of metastases and HCC spread are discussed as well as the imaging findings as seen by both conventional imaging techniques and by molecular imaging tools, namely 18F-Choline PET/CT, and FDG PET. The implications of guiding treatment planning have also been discussed.

Elevated serum alpha-fetoprotein levels are associated with poor prognosis of hepatocellular carcinoma after surgical resection: A systematic review and meta-analysis

BACKGROUND AND STUDY AIMS

The relationship between the alpha-fetoprotein (AFP) level and the prognosis of hepatocellular carcinoma (HCC) after surgical resection remains unknown. This study aims to assess this relationship.

PATIENTS AND METHODS

PubMed and Web of Science were systematically utilised. Meta-analysis was conducted for the outcomes of the recurrence-free survival (RFS) and the overall survival (OS) by comparing the high AFP group with the low AFP group.

RESULTS

The studies included 61 manuscripts with 35,461 patients. The summary hazard ratio (HR) for RFS was 1.501 (95% CI 1.355-1.662; Z = 7.81, P < 0.00001) when comparing the high AFP group with the low AFP group. Sensitivity analysis only included adjusted HRs, with the summary HR being 1.563 (95% CI 1.381-1.768; Z = 7.10, P < 0.00001). The summary HR for OS was 1.565 (95% CI 1.439-1.701; Z = 10.52, P < 0.00001) when comparing two AFP groups. Sensitivity analysis showed that the summary HR was 1.611 (95% CI 1.456-1.782; Z = 9.24, P < 0.00001).

CONCLUSION

Our meta-analysis indicated that elevated serum AFP levels are associated with poor prognosis of HCC after surgical resection.

The Role of 18F-FDG PET/MRI in the Assessment of Primary Intrahepatic Neoplasms

RATIONALE AND OBJECTIVES

To evaluate the results of 18F-FDG PET/MRI in relation to the histopathologic subtypes and histologic grades of mass-forming primary intrahepatic neoplasms.

MATERIALS AND METHODS

We retrospectively evaluated 18F-FDG positron emission tomography/magnetic resonance imaging (PET/MRI) results for 39 patients with histopathologically confirmed primary hepatic neoplasms, 15 with mass-forming intrahepatic cholangiocarcinoma (ICC) and 24 with hepatocellular carcinoma (HCC). The apparent diffusion coefficient (ADC) and standardized uptake value (SUV) were analyzed in relation to the histopathologic diagnosis and histologic grade, including calculating the sensitivity and specificity of the imaging findings.

RESULTS

The median SUV of ICC (6.0 [interquartile range, 5-10]) was significantly higher than that of HCC (4.0 [2.62-6.50]) (p = 0.002). An area under the curve (AUC) of 0.79 (95% confidence interval 0.649-0.932) had a sensitivity of 86.7% and a specificity of 67% at the best cut-off SUV of 4.41 to differentiate between ICC and HCC. ADC values did not differ significantly between HCCs and ICCs (p = 0.283). Both SUV and ADC values differed significantly between low-grade (well- and moderately differentiated) and high-grade (poorly differentiated) HCCs. Combining ADC and SUV further improved differentiation of low- from high-grade HCCs to a significant level (0.929). The SUV did not differ significantly between ICC histologic grades (p = 0.280), while the ADC differed significantly only between well and poorly differentiated ICCs (p = 0.004).

CONCLUSION

Assessing primary hepatic neoplasms with 18F-Fluorodeoxyglucose PET/MRI may help to predict tumor grade and differentiate between types of intrahepatic neoplasms.

Efficacy and Safety of Ramucirumab in Patients with Unresectable Hepatocellular Carcinoma with Progression after Treatment with Lenvatinib

Objective A survival benefit was demonstrated for ramucirumab (RAM) in patients with unresectable hepatocellular carcinoma (uHCC) and α-fetoprotein (AFP) concentrations ≥400 ng/mL who had previously received sorafenib (SOR). However, it is unclear whether RAM has a similar efficacy in patients with uHCC that progresses after lenvatinib (LEN) treatment. This study aimed to evaluate the early anti-tumor response to RAM as a second-line treatment for advanced uHCC after LEN treatment. Methods We retrospectively assessed the efficacy and safety of RAM at 6 weeks after initiation. The therapeutic effects were evaluated according to the Response Evaluation Criteria in Solid Tumors version 1.1. Patients We evaluated 7 patients with uHCC who received RAM as a second- or third-line treatment after LEN failure. Results The disease control rate (DCR) was 28.6% (2 of 7 patients). After the initiation of RAM, a rapid disease progression resulted in 1 patient death after 19 days. The median progression-free survival (PFS) was 41 days. There were no grade 3 or 4 treatment-related adverse events. At 6 weeks, there was no deterioration in the modified albumin-bilirubin (mALBI) grade. In patients with an imaging response of stable disease (SD), the rate of AFP production decreased from the baseline. Conclusion RAM may have a therapeutic potential for the suppression of uHCC progression in patients previously treated with LEN, as well as for maintaining the liver function during treatment. Evaluating the AFP trends may therefore be useful for predicting RAM effectiveness.

Clinico-Radio-Pathological and Molecular Features of Hepatocellular Carcinomas with Keratin 19 Expression

Hepatocellular carcinoma (HCC) is a heterogeneous neoplasm, both from the molecular and histomorphological aspects. One example of heterogeneity is the expression of keratin 19 (K19) in a subset (4-28%) of HCCs. The presence of K19 expression in HCCs has important clinical implications, as K19-positive HCCs have been associated with aggressive tumor biology and poor prognosis. Histomorphologically, K19-positive HCCs demonstrate a more infiltrative appearance, poor histological differentiation, more frequent vascular invasion, and more intratumoral fibrous stroma than K19-negative conventional HCCs. From the molecular aspect, K19-positive HCCs have been matched with various gene signatures that have been associated with stemness and poor prognosis, including the G1-3 groups, S2 class, cluster A, proliferation signature, and vascular invasion signature. K19-positive HCCs also show upregulated signatures related to transforming growth factor-β pathway and epithelial-to-mesenchymal transition. The main regulators of K19 expression include hepatocyte growth factor-MET paracrine signaling by cancer-associated fibroblast, epidermal growth factor-epidermal growth factor receptor signaling, laminin, and DNA methylation. Clinically, higher serum alpha-fetoprotein levels, frequent association with chronic hepatitis B, more invasive growth, and lymph node metastasis have been shown to be characteristics of K19-positive HCCs. Radiologic features including atypical enhancement patterns, absence of tumor capsules, and irregular tumor margins can be a clue for K19-positive HCCs. From a therapeutic standpoint, K19-positive HCCs have been associated with poor outcomes after curative resection or liver transplantation, and resistance to systemic chemotherapy and locoregional treatment, including transarterial chemoembolization and radiofrequency ablation. In this review, we summarize the currently available knowledge on the clinico-radio-pathological and molecular features of K19-expressing HCCs, including a detailed discussion on the regulation mechanism of these tumors.

Potential and Clinical Significance of 18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography for Evaluating Liver Cancer Response to Lenvatinib Treatment

BACKGROUND

The sensitivity of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in hepatocellular carcinoma (HCC) is low; however, clinical evidence demonstrating its prognostic value in patients with HCC has recently been reported. This study aimed to assess the value of 18F-FDG-PET/CT as a tool for evaluating the response of HCC to lenvatinib treatment.

METHODS

We evaluated 11 consecutive patients with HCC diagnosed by dynamic CT or magnetic resonance imaging combined with 18F-FDG-PET/CT from April 2018 to December 2019. The tumor-to-normal liver ratio (TLR) of the target tumor was measured before and during the course of lenvatinib treatment with 18F-FDG-PET/CT (pre and post analysis, respectively), with a TLR ≥2 classified as PET-positive HCC. At the time of each evaluation, we also used the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1, the modified RECIST (mRECIST), and the tumor marker alfa-fetoprotein (AFP).

RESULTS

Of 11 patients, 3 (27%) and 8 (73%) had an objective response to lenvatinib treatment at the time of post-analysis by RECIST 1.1 and mRECIST, respectively. There were 3 (27%) and 7 (64%) patients with PET-positive HCC at the time of pre- and post-analysis, respectively. There was a significant correlation between the rates of change in AFP and TLR during lenvatinib treatment (r = 0.69, p = 0.019). Based on these results, we were able to perform liver resection on 4 patients with PET-positive HCC as conversion therapy. Three samples from these patients showed poorly differentiated tumors.

CONCLUSION

18F-FDG-PET/CT has potential as an evaluation tool for describing biological tumor behavior and reflecting disease progression, location, and treatment response. This modality may provide useful information for considering prognosis and subsequent therapy.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography in patients with small hepatocellular carcinoma treated by radiofrequency ablation

BACKGROUND

¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) uptake in hepatocellular carcinoma (HCC) is significantly associated with early recurrence and survival after curative surgical resection. However, there are no reports regarding the relationship between ¹⁸F-FDG uptake and outcomes after radiofrequency ablation (RFA). A prospective cohort study was conducted to evaluate the prognostic value of ¹⁸F-FDG positron emission tomography (PET) in HCC patients after RFA.

METHODS

A total of 121 consecutive patients with primary HCC (≤3 tumors, of diameter ≤ 3 cm) without vascular invasion on imaging were examined by ¹⁸F-FDG-PET computed tomography prior to RFA. An HCC with a component of ¹⁸F-FDG uptake visibly stronger than that of surrounding liver was defined as ¹⁸F-FDG-PET positive.

RESULTS

The median follow-up period was 1267 days. There were 110 ¹⁸F-FDG-PET negative and 11 positive tumors. The cumulative 1-year recurrence rates in the ¹⁸F-FDG negative and positive groups were 30 and 64% (P = 0.017), respectively, and cumulative 1-year metastatic recurrence rates were 6 and 36% (P < 0.001), respectively. The cumulative 5-year survival rates were 88 and 22% (P < 0.001), respectively. Multivariate analysis revealed ¹⁸F-FDG-PET positivity and tumor size as independent factors related to metastatic recurrence and survival after RFA.

CONCLUSIONS

¹⁸F-FDG-PET positivity was significantly associated with outcomes after RFA. RFA should not be readily selected as the first-line treatment for small HCC that includes a component of visually strong ¹⁸F-FDG uptake.

18F-fluorodeoxyglucose PET/CT as an independent predictor for patients with hepatocellular carcinoma combined with major portal vein tumor thrombus

PURPOSE

Hepatocellular carcinoma (HCC) patients with major portal vein tumor thrombosis (mPVTT) complications were generally characterized by extremely poor prognoses. The aim of this study was to explore the role of 18F-fluorodeoxyglucose (18F-FDG) PET/CT imaging in predicting HCC complicated by mPVTT.

METHODS

Five hundred one HCC patients received surgery in our hospital during November 2008 to December 2014, among which 32 patients (6.4%) were diagnosed as HCC complicated by mPVTT. Six cases were excluded for reasons of complex medical conditions, including 2 cases of salvage liver transplantation, 2 cases of re-resection, 1 case of mPVTT combined with inferior vina cava tumor thrombosis, and 1 case of residual portal vein tumor thrombosis. Ultimately, 26 cases were enrolled in this study. The maximal tumor standardized uptake value (SUVmax) was identified as a predictive factor and detected. The univariate and multivariate regression analyses were performed to identify the prognostic factors for recurrence-free survival (RFS) and overall survival (OS) of HCC patients complicated by mPVTT.

RESULTS

Our results showed that the median OS was 16 months. The 1-, 3-, and 5-year cumulative OS was 55.6%, 31.7%, and 31.7%, respectively. The multivariate regression analysis revealed that SUVmax ≥ 4.65 was the only independent risk factor for RFS and OS.

CONCLUSION

SUVmax was an independent predictor for RFS and OS of patients suffering from both HCC and mPVTT. L ow SUVmax could serve as an effective factor for selecting candidates with low recurrence risks and for helping with improving patient survival after surgical resection.

Pretreatment Heterogeneous Enhancement Pattern of Hepatocellular Carcinoma May Be a Useful New Predictor of Early Response to Lenvatinib and Overall Prognosis

OBJECTIVE

The aim of this study was to evaluate the performance of pretreatment computed tomography (CT) enhancement of hepatocellular carcinoma (HCC) as a potential predictor of response to lenvatinib and its relevance to survival outcomes.

METHODS

We evaluated 51 consecutive patients who received lenvatinib treatment for unresectable HCC. On imaging analysis, pretreatment arterial/portal phase dynamic CT images were classified as follows: type 2, homogeneous enhancement pattern with increased arterial blood flow; type 3, heterogeneous enhancement pattern with a septum-like structure; and type 4, heterogeneous enhancement pattern with irregularly shaped ring structures. Treatment response was evaluated using modified Response Evaluation Criteria in Solid Tumors at 2-12 weeks after initiation of lenvatinib, and the correlations between the CT enhancement patterns and response to lenvatinib or survival outcomes were investigated.

RESULTS

Of the 51 patients, 38 (75%) experienced an objective response (OR). ORs were significantly more common in heterogeneously enhanced HCC (types 3 and 4) than in homogeneous HCC (type 2) (83 vs. 53%, respectively; p = 0.037). Multivariate analysis revealed that pretreatment heterogeneous enhancement pattern is an independent predictor for response to lenvatinib (odds ratio, 4.75; p = 0.042). Presence of OR was associated with longer progression-free survival (PFS) (hazard ratio, 0.36; p = 0.017), and patients with oncologically aggressive type 3 and 4 tumors showed similar PFS to those harboring type 2 tumors (p = 0.455), reflecting that OR was more common in type 3 or 4 tumors compared with type 2 tumors. Although postprogression survival was extremely poor in patients with type 4 tumors (p = 0.064), overall survival after introduction of lenvatinib was not statistically different among the three groups of patients (p = 0.053).

CONCLUSION

The CT enhancement pattern of HCC may predict response to lenvatinib. OR seems to occur more frequently in HCC with oncologically aggressive features and may contribute to prolonged survival through a prolonged progression-free interval, even in an oncologically poor-risk group of patients.

Adenine Nucleotide Translocase 2 as an Enzyme Related to [18F] FDG Accumulation in Various Cancers

PURPOSE

Although glucose transporter 1 (GLUT1) and hexokinase 2 (HK2) are known as major proteins involved in the molecular mechanisms for accumulating 2-deoxy-2-[¹⁸F]fluoro-D-glucose ([¹⁸F]FDG) in cancer cells, sometimes, [¹⁸F] FDG accumulation cannot be explained by the expression of these two proteins. We investigated the involvement of adenine nucleotide translocase 2 (ANT2), which catalyzes ADP/ATP exchange at the mitochondrial inner membrane, in [¹⁸F] FDG accumulation.

PROCEDURES

ANT2 expression was evaluated in various cancer cell lines and human cancer tissues (microarrays) using western blot and immunohistochemical (IHC) staining, respectively. The expression levels of ANT2 were compared to [¹⁸F] FDG accumulation and pathologic findings, including differentiation grade. Additionally, we modulated ANT2 expression levels using ANT2 siRNA and an ANT2 expression vector in cancer cells and murine xenografted tumors.

RESULTS

[¹⁸F] FDG accumulation correlated with ANT2 expression in various cancer cell lines; this was not explained by GLUT1 and/or HK2 expression. At both the cell and tissue levels, ANT2 expression was high in less-differentiated or more malignant type of cancers. [¹⁸F] FDG accumulation changed according to the modulation of the ANT2 expression level.

CONCLUSION

In various cancer cells and tissues, the expression levels of ANT2 explained [¹⁸F] FDG accumulation better than those of GLUT1 and HK2. ANT2 can be used as a marker of dedifferentiated pathology and aggressiveness of cancer.

Genomic Signature of the Standardized Uptake Value in 18F-Fluorodeoxyglucose Positron Emission Tomography in Breast Cancer

The standardized uptake value (SUV), an indicator of the degree of glucose uptake in ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), has been used for predicting the clinical behavior of malignant tumors. However, its characteristics have been insufficiently explored at the genomics level. Here, we aim to identify genomic signatures reflecting prognostic SUV characteristics in breast cancer (BRC). Through integrative genomic profiling of 3710 BRC patients, including 254 patients who underwent preoperative FDG-PET, we identified an SUV signature, which showed independent clinical utility for predicting BRC prognosis (hazard ratio [HR] 1.27, 95% confidence interval [CI] = 1.12 to 1.45, p = 2.23 × 10⁻⁴). The risk subgroups classified by the signature exhibited mutually exclusive mutation patterns of TP53 and PIK3CA and showed significantly different responsiveness to immunotherapy. Experimental assays revealed that a signaling axis defined by TP53–FOXM1 and its downstream effectors in glycolysis–gluconeogenesis, including LDHA, might be important mediators in the FDG-PET process. Our molecular characterizations support an understanding of glucose metabolism and poor prognosis in BRC with a high SUV, utilizable in clinical practice to assist other diagnostic tools.

[18 F]-Fluoro-2-deoxy-D-galactose positron emission tomography/computed tomography as complementary imaging tool in patients with hepatocellular carcinoma

BACKGROUND & AIMS

Positron emission tomography (PET) with the liver-specific tracer [¹⁸ F]-fluoro-2-deoxy-D-galactose (¹⁸ F-FDGal) can be used for imaging of hepatocellular carcinoma (HCC). Curative intended and locoregional treatments of HCC require absence of extrahepatic disease. The aim of this prospective study was to determine whether adding ¹⁸ F-FDGal PET/CT to standard work-up changes the planned treatment in patients with HCC deemed suitable for curative or locoregional treatment.

METHODS

Fifty patients with HCC were included at our tertiary liver centre. The primary study outcome was a change in treatment strategy. A subgroup of 29 patients was also examined with [¹⁸ F]-fluoro-2-deoxy-D-glucose (¹⁸ F-FDG) PET/CT for comparison.

RESULTS

¹⁸ F-FDGal PET/CT detected eight extrahepatic HCC metastases in six patients (12%), which were primarily not detected by ceCT or MRI. These findings led to a change in treatment in five patients (10%). One of the eight extrahepatic HCC foci was also detected by ¹⁸ F-FDG PET/CT. A total of 85 malignant intrahepatic foci were examined, 12 of these were new findings by ¹⁸ F-FDGal PET/CT which had a sensitivity of 71%, highest for large foci. None of the additional intrahepatic foci found by ¹⁸ F-FDGal PET changed the planned treatment.

CONCLUSIONS

For the detection of extrahepatic HCC metastases, ¹⁸ F-FDGal PET/CT was superior both to standard clinical work-up with contrast-enhanced CT, and/or MRI, and to ¹⁸ F-FDG PET/CT in patients deemed suitable for locoregional treatment. ¹⁸ F-FDGal PET/CT led to a change in the planned treatment in 10% of the patients whereas ¹⁸ F-FDG PET/CT did not change the planned treatment in any patient.

18F-Fluorodeoxyglucose Uptake in Hepatocellular Carcinoma as a Useful Predictor of an Extremely Rapid Response to Lenvatinib

BACKGROUND AND AIMS

This study aimed to identify the utility of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT) as a predictor of the response of hepatocellular carcinoma (HCC) to lenvatinib.

METHODS

We evaluated 28 consecutive patients with HCC diagnosed by dynamic CT or magnetic resonance imaging combined with ¹⁸F-FDG-PET/CT. The tumor-to-normal liver standardized uptake value ratio (TLR) of the target tumor was measured before treatment using ¹⁸F-FDG-PET/CT, with a TLR ≥2 classified as a high potential for malignant HCC. The treatment response was evaluated 2 weeks after the initiation of lenvatinib using modified Response Evaluation Criteria in Solid Tumors.

RESULTS

Of the 28 patients, 12 (43%) presented with a TLR ≥2. Evaluation of the treatment response at 2 weeks in these 12 patients revealed that 2 (17%) exhibited a complete response, 8 (67%) a partial response, 2 (17%) stable disease, and none with progressive disease. Therefore, 10 of the 12 patients (83%) experienced an objective response to lenvatinib. On the other hand, 7 of the 16 patients with a TLR <2 (44%) experienced an objective response. Thus, the objective response rate was higher in patients with a TLR ≥2 than in those with a TLR <2. Multivariate logistic regression analysis revealed that a TLR ≥2 (odds ratio 10.53; p = 0.028) is a useful predictor of an early objective response at 2 weeks.

CONCLUSION

Patients with unresectable HCC showed a good early treatment response to lenvatinib. High TLR (≥2) may be a useful predictor of an extremely rapid treatment response.

Hypoxia-induced modulation of glucose transporter expression impacts 18F-fluorodeoxyglucose PET-CT imaging in hepatocellular carcinoma

PURPOSE

To investigate the molecular mechanisms underlying the variable standard uptake value (SUV) of ¹⁸F-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸F-FDG PET-CT) imaging in hepatocellular carcinoma (HCC) and whether hypoxia-induced glucose transporter expression contributes to the progression of HCC and the rate of glycolysis in HCC cells.

MATERIALS AND METHODS

Sixteen HCC specimens obtained from patients who underwent pre-treatment staging with ¹⁸F-FDG PET-CT imaging were divided into high maximum SUV (SUV_max > 8) and low SUV_max (SUV_max < 5) groups and employed for whole-genome gene expression profiling using GeneChip Human Genome U133 Plus 2.0 Arrays. The relationship between SUV_max and the expression of glucose transporters 1 and 3 (GLUT1 and GLUT3) was further validated using immunohistochemical analysis. The expression of GLUT1 and GLUT3 in different HCC cells under hypoxia and normoxia conditions were monitored by quantitative reverse transcription PCR (RT-qPCR). Glycolysis and FDG uptake by HCC cells were measured using the Seahorse XF glycolysis stress test and ¹⁸F-FDG PET-CT imaging. The effect of GLUT1 and GLUT3 on glucose uptake in HCC cells was examined using the fluorescent D-glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-d-glucose (2-NBDG) followed by detection of fluorescence produced by the cells using flow cytometry.

RESULTS

Glucose transporters are differentially expressed between samples from HCC patients with high and low SUV_max. In particular, over-expression of GLUT1 and GLUT3 in high SUV_max patients was correlated with high glucose uptake and overall survival. The expression of GLUT1 and GLUT3 was significantly induced by hypoxia in different HCC cells. High expression of GLUT1 and GLUT3 in HCC cells were correlated with high rates of glycolysis and 18F-FDG uptake. Therefore, our data suggested that hypoxia-induced glucose transporters expression could result in the variations of ¹⁸F-FDG PET-CT imaging and progression of HCC, contributing to more aggressive disease phenotypes like large tumor size, recurrence, and poor survival.

CONCLUSION

Over-expression of GLUT1 and GLUT3 significantly increase glucose uptake in HCC cells. Hypoxia-induced glucose transporters expression may therefore be a contributing variable in ¹⁸F-FDG PET-CT imaging and progression in HCC.

18F-FDG PET/CT predicts microvascular invasion and early recurrence after liver resection for hepatocellular carcinoma: A prospective observational study

BACKGROUND

This study assessed the prognostic value of 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) in the prediction of MVI and early recurrence following resection.

METHOD

This prospective study (ClinicalTrials.gov ID: NCT02145013) included 78 consecutive HCC patients who underwent 18F-FDG PET/CT before curative-intent resection from 2014 to 2017. Prognostic factors available before surgery for predicting MVI and early recurrence (≤2 years) were identified by univariate and multivariate analyses.

RESULTS

The 18F-FDG PET/CT result was positive in 30 (38%) patients. MVI was present in 33% (26/78) of specimens. Early recurrence occurred in 19% (14/74) of surviving patients. PET/CT positivity was the sole independent predictor of MVI (odds ratio [OR] = 3.6, 95% confidence interval [CI] = 1.1-11.2; p = 0.03), with a specificity and sensitivity for predicting MVI of 73% and 62%, respectively. Analysis of variables available before surgery showed that PET/CT positivity (hazard ratio [HR] = 5.8, 95% CI = 1.6-20.4; p = 0.006) and the male sex (HR = 6.6; 95% CI = 1.8-24.2; p = 0.005) were independent predictors of early recurrence.

CONCLUSION

18F-FDG PET/CT predicts MVI and early recurrence after surgery for HCC and could be used to select patients for neoadjuvant treatment.

18F-fludeoxyglucose positron emission tomography for diagnosis of HCC: implications for therapeutic strategy in curative and non-curative approaches

Hepatocellular carcinoma (HCC) is a global health issue with increasing incidence and high mortality rate. Depending on the tumor load and extent of underlying liver cirrhosis, aggressive surgical treatment by hepatectomy or liver transplantation (LT) may lead to cure, whereas different modalities of liver-directed locoregional or systemic tumor treatments are currently available for a noncurative approach. Apart from tumor burden and grade of liver dysfunction, assessment of prognostic relevant biological tumor aggressiveness is vitally important for establishing a promising multimodal therapeutic strategy and improving the individual treatment-related risk/benefit ratio. In recent years, an increasing body of clinical evidence has been presented that ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), which is a standard nuclear imaging device in oncology, may serve as a powerful surrogate for tumor invasiveness and prognosis in HCC patients and, thereby, impact individual decision making on most appropriate therapy concept. This review describes the currently available data on the prognostic value of ¹⁸F-FDG PET in patients with early and advanced HCC stages and the resulting implications for treatment strategy.

18F-FDG PET/CT AS AN ASSESSMENT TOOL OF HEPATOCELLULAR CARCINOMA SECONDARY TO NON-ALCOHOLIC FATTY LIVER DISEASE DEVELOPMENT IN EXPERIMENTAL MODEL

BACKGROUND

Hepatocellular carcinoma (HCC) can be the last step of non-alcoholic fatty liver disease (NAFLD) evolution. Experimental models are crucial to elucidate the pathogenesis of HCC secondary to NAFLD. The 2-deoxy-2-(18F)fluoro-D-glucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) plays an important role in evaluating HCC development and progression.

OBJECTIVE

To standardize the imaging method of PET/CT with 18F-FDG as an evaluation tool of the experimental model of HCC secondary to NAFLD.

METHODS

Ten male Sprague-Dawley rats were fed with choline-deficient high-fat diet and diethylnitrosamine (DEN) in the drinking water for 16 weeks and then received 1 mL of saline solution (0.9%) daily by gavage for three weeks. At the 16th and 19th weeks, abdominal ultrasonography (USG) was performed. 18F-FDG PET/CT images were obtained before the beginning of experiment (week 0) and at the end (week 19). Histological and immunohistochemically analysis were also performed.

RESULTS

The USG results showed a homogeneous group at the 16th week with an average of 4.6±2.74 nodules per animal. At the 19th week, PET/CT findings demonstrated an average of 8.5±3.7 nodules per animal. The mean values of SUVmed and SUVmax were 2.186±0.1698 and 3.8±1.74, respectively. The average number of nodules per animal in the histological analysis was 5.5±1.5. From all nodules, 4.6% were classified as well-differentiated HCC and 81.8% were classified as poorly-differentiated HCC.

CONCLUSION

18F-FDG PET/CT was able to evaluate the development of HCC in an experimental model of NAFLD non-invasively. From the standardization of PET/CT in this model, it is possible to use this tool in future studies to monitor, in vivo and non-invasively, the progression of HCC.

Prognostic value of pretreatment PET/CT lean body mass-corrected parameters in patients with hepatocellular carcinoma

OBJECTIVE

This study was designed to investigate whether pretreatment fluorine-18-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) lean body mass-corrected parameters could predict the overall survival (OS) better than the established predictors in patients with hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

We retrospectively analyzed 61 patients with HCC with pretreatment F-FDG-PET/CT. Besides obtaining clinical factors, we measured both lean body mass-corrected and body weight-corrected PET/CT parameters, including metabolic tumor volume, maximal standardized uptake value of the tumor, total lesion glycolysis, tumor-to-normal liver uptake ratio, and so on. The prognostic value of those factors for OS was assessed by statistical software.

RESULTS

In the univariate analysis, PET/CT parameters, ascites, serum α-fetoprotein, alkaline phosphatase, aspartate transaminase (AST), tumor number, tumor size of the maximal one, vascular invasion, TNM stage, Child-Pugh class, Barcelona Clinic Liver Cancer (BCLC) staging, and Okuda staging were significant predictors of OS. In multivariate and Kaplan-Meier analyses, lean body mass-corrected maximum standardized uptake value (lbmSUVmax) more than 3.35 g/ml, AST more than 42.00 U/l, and BCLC staging B-C were significant independent predictors of poor OS. When BCLC staging variable was stratified by four categories instead of two in the multivariate analysis, it was not the statistically significant independent predictor anymore, but lbmSUVmax and AST still were.

CONCLUSION

Pretreatment F-FDG-PET/CT lean body mass-corrected parameters can predict the OS in patients with HCC. Moreover, lbmSUVmax and AST, as the independent predictors of OS, could supplement the prognostic value of the BCLC staging system.

11C-acetate and 18F-fluorodeoxyglucose positron emission tomography/computed tomography dual imaging for the prediction of response and prognosis after transarterial chemoembolization

The aim of the present study was to evaluate the clinical significance of dual radiotracer studies, C-acetate and F-fluoro-D-glucose positron emission tomography/computed tomography (F-FDG PET/CT), for the prediction of response and recurrence after transarterial chemoembolization (TACE).This study retrospectively included a total 42 hepatoceullar carcinoma (HCC) patients (median age, 59; range, 34-85 years old) who underwent C-acetate and F-FDG PET/CT concurrently. Tumor uptake normalized by liver uptake (TNR; maximum tumor SUV to mean normal liver SUV ratio) was obtained first. Then, FAratio, which is the ratio of F-FDG TNR (TNR_FDG) to C-acetate TNR, was obtained and correlated with response after TACE and recurrence-free survival (RFS), using a Cox multivariate proportional-hazard model.Among clinical factors, including the Hepatoma Arterial Embolization Prognostic score and positron emission tomography (PET) parameters, multiple regression analysis revealed FAratio and tumor size to be the only significant factors. As a PET parameter, FAratio exhibited the largest area under the curve in the prediction of response after TACE. In the Cox multivariate proportional-hazard model, TNR_FDG was the only significant predictive factor for RFS. In subgroup analysis, TNR_FDG was the only significant predictive factor for recurrence in intermediate stage patients. However, FAratio was the only significant predictive factor for recurrence in advanced stage patients.Dual radiotracer use of C-acetate and F-FDG PET/CT contributed to the prediction of response and recurrence after TACE. Used in addition to F-FDG, C-acetate PET/CT could give additional information in advanced stage patients. Based on the characteristics of tumor metabolism assessed by dual radiotracer PET/CT, treatment plans could be more personalized and optimized.

18F-FDG PET with or without CT in the diagnosis of extrahepatic metastases or local residual/recurrent hepatocellular carcinoma

The aim of the present study was to meta-analyze the literature on the diagnostic value of 18-fluorodeoxyglucose (F-FDG) positron emission tomography (PET) with or without computed tomography (CT) in detecting extrahepatic metastases or local residual/recurrent hepatocellular carcinoma (HCC).Systematic review of literature in MEDLINE, Embase, and Cochrane databases was conducted in March 2017, and relevant studies analyzing the diagnostic performance of F-FDG PET with or without CT were meta-analyzed.Meta-analysis was carried out on data from 11 studies involving 572 patients. F-FDG PET, with or without CT, showed pooled sensitivity of 64% and pooled specificity of 95%. Pooled sensitivity was similar with CT (74%) or without (52%; P = .279). Similarly, pooled specificity was comparable with CT (93%) or without 95% (P = .481).F-FDG PET, with or without CT, shows relatively low sensitivity but high specificity for diagnosing extrahepatic metastases or local residual/recurrent HCC. Adding CT to F-FDG PET may improve diagnostic performance, but the available evidence suggests that the improvement is not statistically significant.

Efficacy of contrast-enhanced FDG PET/CT in patients awaiting liver transplantation with rising alpha-fetoprotein after bridge therapy of hepatocellular carcinoma

OBJECTIVE

To assess the diagnostic accuracy and illustrate positive findings of contrast-enhanced fluorine-18 fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) image in patients awaiting liver transplantation (LT) with rising alpha-fetoprotein (AFP) after bridge therapy of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This prospective study included 100 patients who were waiting for LT and who previously underwent locoregional therapy (LRT) of HCC. These patients had rising AFP levels on a routine follow-up examination awaiting LT. All patients underwent a contrast-enhanced ¹⁸F-FDG PET/CT examination. We calculated for each patient the maximum standardised uptake value (SUVmax) of the tumour and the ratio of the tumoral SUVmax to the normal-liver SUVmax. The diagnostic accuracy and positive contrast-enhanced findings of ¹⁸F-FDG PET/CT were established by histopathology and clinical and imaging follow-up as the reference standards.

RESULTS

Contrast-enhanced ¹⁸F-FDG PET/CT detected tumour relapse in 78 patients (13 patients had intrahepatic lesions, 10 patients had extrahepatic metastases and 55 patients with combined lesions). The sensitivity, specificity and accuracy values of contrast-enhanced ¹⁸F-FDG PET/CT examination in the detection of HCC recurrence were 92.8%, 94.1% and 93%, respectively. A significant correlation was found between the AFP level and SUVmax ratio (r = 0.2283; p = 0.0224). The best threshold for ¹⁸F-FDG PET positivity was >1.21.

CONCLUSION

Contrast-enhanced ¹⁸F-FDG PET/CT is a valuable tool for the detection of intrahepatic HCC recurrence or extrahepatic metastasis following rising AFP levels after LRT of HCC, and should be incorporated during routine workup awaiting LT.

KEY POINTS

• ¹⁸F-FDG PET/CT is a valuable tool for the detection of HCC recurrence • ¹⁸ F-FDG PET/CT should be incorporated during routine workup awaiting liver transplantation • Significant correlation was found between AFP level and SUVmax ratio • The best threshold for ¹⁸ F-FDG PET positivity was >1.21 • The ideal cut-off value for AFP was >202.

Combined [18F]-Fluoroethylcholine PET/CT and 99mTc-Macroaggregated Albumin SPECT/CT Predict Survival in Patients With Intermediate-Stage Hepatocellular Carcinoma

AIM

The aim of this study was to retrospectively analyze the prognostic value of combined Tc-macroaggregated albumin (MAA) SPECT/CT and [F]-fluoroethylcholine (FEC) PET/CT before radioembolization for survival of patients with intermediate-stage hepatocellular carcinoma.

METHODS

Twenty-four patients with known hepatocellular carcinoma Barcelona Clinic Liver Cancer stage B were eligible for this analysis. All patients were scheduled for radioembolization and received a pretherapeutic [F]FEC PET/CT scan as well as Tc-MAA SPECT/CT for hepatopulmonary shunting. Laboratory and semiquantitative PET parameters and morphologic and metabolic (intersection) volumes of MAA and FEC were evaluated. Spearman correlation with overall survival, receiver operating curve analyses, univariate and multivariate Cox regression, and Kaplan-Meier-analysis was applied.

RESULTS

All patients (5 female/19 male) are deceased within the observational period. Median survival was 395 days (±51 days; range, 23-1122 days). The percentage of hypervascularized metabolically active tumor volume (vascularized tumor ratio; defined as high MAA and FEC uptake) correlated significantly with survival. Vascularized tumor ratio was a significant predictor in univariate and multivariate analyses (P = 0.026; hazard ratio, 11.65; 95% confidence interval, 1.62-83.73; P = 0.015). Statistical significance was not reached by all other variables in multivariate analysis. Receiver operating curve analysis for 1-year survival revealed an area under the curve of 0.77 (P = 0.024) for vascularized tumor ratio. At a cutoff value of 9%, sensitivity, specificity, and positive and negative prediction were 83%, 67%, and 71% and 80% (P = 0.036). Patients with a higher tumor vascularization had a median survival of 274 ± 80 versus 585 ± 284 days (P = 0.015).

CONCLUSIONS

Hepatocellular carcinoma with high vascularization in metabolic active areas as assessed by combined FEC PET/CT and Tc-MAA SPECT/CT represents an unfavorable subgroup with reduced overall survival after radioembolization.

Prognosis of preoperative positron emission tomography uptake in hepatectomy patients

Purpose

Preoperative F-18-fluoro-2-deoxy-glucose positron emission tomography (18F-FDG PET) imaging results appear to predict tumor recurrence and patient survival. The present study compared outcomes between PET-positive and PET-negative groups with HBV-related hepatocellular carcinoma (HCC) who underwent curative hepatectomy and assessed the prognostic value of positive PET-CT for HCC recurrence and death.

Methods

This study included patients who underwent liver resection of solitary HCC between 2007 and 2014 based on preoperative radiological images. There were 133 patients in the PET-positive group and 93 in the PET-negative group.

Results

There were no statistically significant differences in baseline, perioperative, or pathologic characteristics between the 2 groups except HBsAg titer, tumor size, and presence of bile duct tumor thrombi. Multivariate analysis showed that tumor size >3.5 cm and HBsAg titer >1,000 cutoff index were predisposing factors of positive PET-CT. Disease-free survival and overall survival rate at 1, 3, and 5 years were 76.3%, 64.4%, 60.3% and 96.8%, 91.1%, 85.1% in the PET-negative group, respectively, compared with 70.7%, 62.2%, 58.9% and 98.5%, 97.0%, 97.0% in the PET-positive group (P = 0.547 and P = 0.046). Multivariate analysis showed that positive PET-CT was closely associated with increased patient survival, but was not related to HCC recurrence.

Conclusion

These results suggest that positive PET findings are not a predisposing factor for recurrence of HBV-related HCC patients, but appear to be associated with improved patient survival. Further prospective studies are needed to confirm the prognostic value of 18F-FDG PET in these patients.

Clinical usefulness of FDG-PET in patients with hepatocellular carcinoma undergoing surgical resection

Backgrounds/Aims

Diagnosis and staging of hepatocellular carcinoma (HCC) is critical because of the variety of treatment methods and prognosis. [¹⁸F]fludeoxyglucose-positron emission tomography/computed tomography ([¹⁸F]FDG-PET/CT) has been suggested as a diagnostic modality in HCC. The purpose of this study is to evaluate the accuracy of FDG-PET for staging of HCC after surgical resection and histological confirmation.

Methods

We retrospectively collected data of 56 patients that underwent FDG-PET before surgical resection for HCC March 2011–May 2017, all of whom were suitable for resection by conventional HCC staging. Results of the maximal standardized uptake value (SUVmax) were compared with histological confirmation.

Results

A larger tumor size was related with higher SUVmax (≥4.9). The serum alpha-feto protein was associated with SUVmax. Recurrence rate was higher in patients with higher SUVmax and patients with lower SUVmax had a better survival rate.

Conclusions

The SUVmax correlates well with tumor size and factors associated with biological behavior of HCC such as alpha-feto protein, and it could be a beneficial modality in providing prognostic information for HCC.

Proposal of a New Preoperative Prognostic Model for Solitary Hepatocellular Carcinoma Incorporating 18F-FDG-PET Imaging with the ALBI Grade

BACKGROUND

Existing prognostic systems were not developed using only objective variables available preoperatively, and therefore do not provide ideal prognostication for patients undergoing hepatectomy for hepatocellular carcinoma (HCC). We aimed to develop a preoperative prognostic model using objective variables involving two parameters: ¹⁸F-fluorodeoxyglucose-positron emission tomography (¹⁸F-FDG-PET) and the albumin-bilirubin (ALBI) grade.

METHODS

This study included 207 consecutive patients with solitary HCC who underwent ¹⁸F-FDG-PET prior to hepatectomy. The tumor to non-tumor maximum standardized uptake value ratio (TNR) was used as an ¹⁸F-FDG PET imaging parameter.

RESULTS

The 5-year overall survival (OS) and disease-free survival (DFS) rates were 58.6% and 28.8%, respectively. Multivariate analysis of OS identified TNR ≥ 2 (hazard ratio [HR] 1.743, 95% confidence interval [CI] 1.114-2.648, p = 0.016) and ALBI grade 2 (HR 1.966, 95% CI 1.349-2.884, p < 0.001) as the only significant prognostic factors; tumor diameter and tumor markers were not significant. Patients were divided into low- (TNR < 2 and ALBI grade 1), intermediate- (TNR < 2 and ALBI grade 2, or TNR ≥ 2 and ALBI grade 1), and high-risk (TNR ≥ 2 and ALBI grade 2) groups, which differed significantly in terms of survival (5-year OS: 75.7, 49.6, and 27.3%, respectively, p < 0.001; 5-year DFS: 37.0, 24.9, and 13.6%, respectively, p < 0.001). Compared with other staging systems, our model had the best discriminatory ability (corrected Akaike information criteria 1054.8, p < 0.001) and homogeneity (likelihood ratio Chi square value 27.6, p < 0.001).

CONCLUSION

A preoperative prognostic model incorporating ¹⁸F-FDG-PET imaging with the ALBI grade may be useful for estimating the prognosis of selected patients with solitary HCC.

Identification of keratin 19-positive cancer stem cells associating human hepatocellular carcinoma using CYFRA 21-1

The current lack of an easily measurable surrogate marker of cancer stem cells (CSCs) prevents the clinical application of CSCs for hepatocellular carcinoma (HCC). We previously reported that keratin 19 (K19) is a novel HCC‐CSC marker associated with transforming growth factor beta (TGFβ)/Smad signaling, and that K19⁺ HCC‐CSCs could be a new therapeutic target of TGFβ receptor 1 inhibitor LY2157299. In this study, we examined whether K19⁺ HCC‐CSCs can be tracked using cytokeratin 19 fragment CYFRA 21‐1. In 147 HCC patients who underwent curative resection and evaluated K19 expression by immunohistochemistry, preoperative serum CYFRA 21‐1 levels were significantly higher in K19⁺ patients than in K19⁻ patients (P < 0.01). Receiver operating characteristic analyses revealed that serum CYFRA 21‐1 was the statistically significant and the most sensitive predictor of tumor K19 expression among preoperative laboratory test values (P < 0.001). In HCC cells encoding with a K19 promoter‐driven enhanced green fluorescent protein, fluorescence‐activated cell sorting (FACS)‐isolated K19⁺ cells displayed significantly higher levels of supernatant CYFRA 21‐1 than K19⁻ cells (P < 0.01). Gain/loss of K19 function experiments confirmed that CYFRA 21‐1 levels were regulated by K19 function in HCC cells. Furthermore, CYFRA 21‐1 levels reflected the treatment efficacy of LY2157299 in K19⁺ cells. In conclusion, CYFRA 21‐1 can be used to predict K19 expression in HCC, and should thereby aid in the development of novel therapeutic strategies targeting K19⁺ HCC‐CSCs.

18F-FDG-PET for Assessing Biological Viability and Prognosis in Liver Transplant Patients with Hepatocellular Carcinoma

Liver transplantation (LT) has become standard of care in patients with non-resectable early stage hepatocellular carcinoma (HCC) in liver cirrhosis. Currently, patient selection for LT is strictly based on tumor size and number, provided by the Milan criteria. This may, however, exclude patients with advanced tumor load but favourable biology from a possibly curative treatment option. It became clear in recent years that biological tumor viability rather than tumor macromorphology determines posttransplant outcome. In particular, microvascular invasion and poor grading reflect tumor aggressiveness and promote the risk of tumor relapse. Pretransplant biopsy is not applicable due to tumor heterogeneity and risk of tumor cell seeding. ¹⁸F-fludeoxyglucose (¹⁸F-FDG) positron emission tomography (PET), an established nuclear imaging device in oncology, was demonstrated to non-invasively correlate with unfavorable histopathologic features. Currently, there is an increasing amount of evidence that ¹⁸F-FDG-PET is very useful for identifying eligible liver transplant patients with HCC beyond standard criteria but less aggressive tumor properties. In order to safely expand the HCC selection criteria and the pool of eligible liver recipients, tumor evaluation with ¹⁸F-FDG-PET should be implemented in pretransplant decision process.

Significance of preoperative fluorodeoxyglucose-positron emission tomography in prediction of tumor recurrence after liver transplantation for hepatocellular carcinoma patients: a Japanese multicenter study

BACKGROUND

In the present study, we conducted a multicenter nationwide survey to investigate the effects of preoperative fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography (PET) on the prediction of hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT).

METHODS

From 16 Japanese LT centers, data were collected on 182 recipients with HCC who underwent living donor liver transplantation (LDLT) between February 2005 and November 2013. PET-positive status was defined as increased uptake of FDG in the tumor compared to the surrounding non-tumor liver tissue. The median follow-up after LDLT was 54.5 months (range 1-125 months).

RESULTS

Postoperative HCC recurrence occurred in 23 patients. Multivariate analysis revealed that exceeding the Milan criteria (MC), alpha-fetoprotein (AFP) level ≥115 ng/ml, and PET-positive status were significant and independent risk factors for recurrence. In the over-MC group, a subgroup of patients with AFP level <115 ng/ml and PET-negative status (n = 22) had a significantly lower 5-year recurrence rate than the other patients (n = 27, 19% vs. 53%, P = 0.019).

CONCLUSIONS

These results suggest that preoperative FDG-PET status offers additional information on HCC recurrence risk after LT. Over-MC patients with PET-negative status and lower AFP level may achieve successful outcome comparable to that of within-MC patients.

Combination of FDG-PET and UCSF Criteria for Predicting HCC Recurrence After Living Donor Liver Transplantation

BACKGROUND

F-18 fluorodeoxyglucose (FDG) uptake in hepatocellular carcinoma (HCC) is related to tumor biology and has predictive value for tumor recurrence after liver transplantation. This retrospective study assessed whether the degree of FDG uptake in positron emission tomography (PET) can be used to predict HCC recurrence after living donor liver transplantation (LDLT).

METHODS

One hundred forty-seven patients with HCC underwent FDG-PET studies before LDLT. The semiquantification of FDG uptake in FDG-positive HCC was done with maximum standardized uptake value (SUVmax) and tumor to nontumor ratio (TNR). Recurrence-free survivals (RFS) were calculated using the Kaplan-Meier method.

RESULTS

In univariable analysis, T stage, presence of microvascular invasion, being FDG-positive, SUVmax, and TNR were significant predictors for worse RFS. The optimal cutoff values of SUVmax and TNR were 4.8 and 2.0, respectively. The high FDG uptake HCC (TNR ≥ 2) was a strong predictor for worse RFS (hazard ratio, 13.52; 95% confidence interval, 4.77-38.29; P < 0.001). Using a combination of FDG-PET and University of California San Francisco (UCSF) criteria, the patients can be divided into low-risk (within UCSF criteria and FDG-negative), intermediate-risk (beyond UCSF criteria and FDG-negative; FDG-positive and TNR < 2), and high-risk (FDG-positive and TNR ≥ 2) groups. The estimated 5-year RFS in these groups were 85.5%, 83.9%, and 29.6% according to the combination of FDG-PET and clinical UCSF criteria, and 94.0%, 75.8%, and 29.6% according to the combination of FDG-PET and pathologic UCSF criteria, respectively.

CONCLUSIONS

Combination of FDG-PET and UCSF criteria can be used to predict the risk of HCC recurrence after LDLT.