Researchers have uncovered an upper limit in tumor burden after which there is a lower probability of successfully downstaging patients with hepatocellular carcinoma (HCC) for liver transplantation, according to findings presented at the 2016 AASLD Liver Meeting.

In the small prospective study, tumor burden was negatively predictive of successful downstaging for patients with HCC (HR, 0.87; 

 <.05). Overall, patients with a sum of number of tumors plus largest tumor diameter of 8 had a 68% probability of being downstaged to within Milan criteria at 1 year compared to those with a tumor burden of 14 who had only a 38% probability at 1 year.

“Using this metric of tumor burden, the sum of the number of lesions plus the diameter of the largest tumor, we can see that the greater the tumor burden, the lower the rate of successful downstaging,” said lead investigator Jasmine Rassiwala, MD, MPH, from the University of California, San Francisco (UCSF). “Our results suggest that there does exist an upper limit in tumor burden beyond which successful downstaging to a goal of liver transplant becomes unrealistic.”

Liver transplantation is one of only a few curative therapies for HCC, warranting studies to enhance its use. Eligibility for transplant has traditionally been based on Milan criteria. For patients who do not meet these criteria, the UCSF Down Staging (UCSF-DS) protocol has proven that HCC patients who achieved successful downstaging to Milan criteria had similar outcomes after liver transplant compared to those with HCC initially within Milan criteria (Hepatology 2015; 61:1968-1977).

Downstaging can facilitate liver transplantation for patients outside of Milan criteria. The benefits of downstaging include decreased tumor burden and time to identify those with less aggressive tumor biology. However, downstaging and post-liver transplant outcomes for patients with tumor burden initially exceeding the UCSF-SD’s criteria (>8cm without metastatic evidence or lymphovascular invasion per imaging) is not well known.

To explore these outcomes further, UCSF conducted a prospective cohort study that included 74 patients with HCC enrolled from 2005-2015 with tumor burden beyond UCSF-SD criteria. These patients were defined as “all-comers” did not have evidence of extrahepatic spread or vascular invasion. Outcomes in all-comers were compared with 133 patients that met UCSF-SD criteria who were enrolled over the same period of time.

Those within the all-comer and UCSF-DS groups were similar except there were significantly fewer Asian (18% vs 36%) and more Hispanic patients (24% vs 11%) in the all-comer group compared with the UCSF-DS group, respectively. A diagnosis of hepatitis C virus was more predominant (68% vs 53%) and there were fewer rates of hepatitis B virus (16% vs 29%) and alcoholism (11% vs 17%) in the all-comers group compared with the UCSF-DS group, respectively. Overall, patients in the all-comers group had greater tumor burden than those in the UCSF-DS group (12 cm versus 6.3 cm median tumor diameter).

All comer patients underwent downstaging and were placed on the liver transplant list if they remained within Milan for 6 months versus UCSF-SD’s criteria, which is 3 months. Downstaging was attempted using locoregional therapy (LRT).

At 12 months, 62% of patient in the all-comer group were successfully downstaged compared with 89% of those in the UCSF-SD group. At 24 months, 75% of all-comer patients were downstaged compared with 93% in the UCSF-DS group. Those with a tumor burden of 10, had a 57% probability of being downstage at 1-year. Those with a tumor burden of 12 had a 47% probability of downstaging.

The median time to downstaging was 3.1 months. Of those who were successfully downstaged, 9 (12%) underwent orthotopic liver transplantation in a median time of 7.4 months from downstaging. Seven patients who were downstaged are still awaiting transplant.

At 12 months, 54% of the all-comer patients had dropped out compared with 25% of UCSF-DS patients. At 36 months, the incidence of dropout in the all-comer group was 80% compared with 36% in the UCSF-DS group. The most common reason for dropout in both groups was HCC progression. 

Similar results were found in the post-liver transplant 5-year survival rates. At 5-years, 50% of patients in the all-comers group remained alive compared with 79% in UCSF-DS group (

= .51). Post-liver transplant 5-year recurrence-free survival was 40% in the all-comers group versus 86% in UCSF-DS arm (

“Though this was not a significant difference, significance in this study was largely limited by the only few events within the all-comers cohort,” said Rassiwala. “For reference, 5-year post transplant survival in T2 group within Milan is 81%. UCSF criteria was 75.2%.”

In the intent-to-treat population, the 5-year survival in the all-comers cohort was 21%, which was significantly lower than the survival rate of 56% in the UCSF-DS cohort, Rassiwala noted. The traditional survival rate in the Milan T2 group at 5 years is 63%.

Overall, there was no significant difference in the time from LRT initiation to death between the groups. The median was 13 months in the all comers group and 16.5 months in the UCSF-DS group (

“All-comers have inferior outcomes following downstaging compared to the UCSF-DS group,” Rassiwala concluded. “Future studies are needed to further evaluate prognostic factors to define a subgroup beyond the UCSF-DS criteria who may still achieve acceptable outcomes after downstaging.”

Rassiwala R, Mehta N, Dodge JL, et al. Are There Upper Limits in Tumor Burden for Successful Down-staging of Hepatocellular Carcinoma to Liver Transplant? Analysis of the “All-comers” Down-staging Protocol. AASLD Liver Meeting; Boston, Massachusetts, November 11-15, 2016. Abstract 137.

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In the 9 patients who receive a transplant in the all-comers group, 3 had experienced a recurrence. The median time to recurrence was 21.4 months. The recurrence rate in the UCSF-DS group was 7.5% (5 of 64).

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Researchers have uncovered an upper limit in tumor burden after which there is a lower probability of successfully downstaging patients with hepatocellular carcinoma for liver transplantation.

Tumor Burden Limits Liver Transplant Feasibility for HCC

Multidisciplinary tumor boards led to higher utilization of guideline-recommended curative therapies, which was associated with improved overall survival (OS) for patients with early-stage hepatocellular carcinoma (HCC), according to an observational study conducted by the Veterans Outcomes and Cost Associated with Liver Disease (VOCAL) research group that was presented at the 2016 AASLD Liver Meeting.

"Significant variability was noted for care delivery in HCC in a diverse, national cohort of Veterans," said lead investigator Marina Serper, MD, MS, Division of Gastroenterology and Hepatology, Hospital of the University of Pennsylvania. "Studies to improve multidisciplinary approaches for HCC in the community are needed to increase rates of curative therapy and improve clinical outcomes."

Improving care delivery in HCC involves many factors, with treatment variation and care management at the forefront. In general, the treatment paradigm for HCC is complex, as it depends equally on liver function and tumor staging. As a result, care in HCC is variable due to provider expertise and a range of available therapeutic options.

Ninety-nine percent of patients in the study were males, and 54% were white. The mean age was 62 years (SD ±8). Thirty-six percent of patients were within Milan criteria and 45% of patients had a Child Pugh score of B or higher. Thirty-four percent of patients had an alpha‑fetoprotein (AFP) blood value ≥200 ng/ml.

Patients had an average of 2 lesions (range, 1-4). Overall, 17.5% had microinvasions and 7.2% had metastatic cancer. The top etiologies for liver disease were hepatitis C virus (HCV) infection and alcohol (39%), HCV alone (22%), alcohol alone (15%), and both HCV and hepatitis B virus (HBV; 5%). The liver characteristics at baseline consisted of a Barcelona Clinic Liver Cancer Stage B (33%), A (30%), C (17%), D (14%), and 0 (6%).

The most common HCC therapies received in the frontline setting were sorafenib, transcatheter arterial chemoembolization, or no therapy. In the early stage, there were fewer patients with HCC with a BCLC stage between 0 and 2 receiving curative therapy (resection or ablation) than expected based on treatment guidelines. Additionally, sorafinib was utilized earlier than guidelines indicated.

Clinical factors that negatively impacted the frontline treatment decision included age at diagnosis (odds ratio [OR], 0.77; 

 <.001), ECOG performance status of 3 to 4 (OR, 0.40; 

 <.001), baseline AFP ≥200 ng/mL (OR, 0.80; 

 = .048), and macrovascular invasion (OR, 0.60; 

 <.001). Those within Milan criteria were more likely to receive active therapy (OR, 1.42; 

Delivery variables that positively affected the receipt of active frontline therapy included evaluation by ≥1 specialist (OR, 1.60; 

 = .005) and an academic center affiliation for the treating physician (OR, 1.97; 

 <.001). Treatment was also more likely for those who saw a medical oncologist (OR, 2.56; 

 = .001) within 30 days of diagnosis. Those who saw a gastroenterologist (OR, 0.56; 

 <.001) or a palliative care specialist (OR, 0.24; 

 <.001) were less likely to receive active therapy.

Additionally, Serper noted, “there were differences found between regions, and these data were analyzed. Regions will be presented in an upcoming manuscript.” Care delivery in HCC did vary significantly in this diverse national cohort of Veterans. Furthermore, Serper stated, “This cohort had a higher HCC mortality rate than the overall population.”

Factors associated with improved OS by multivariable analysis were liver transplantation (HR, 0.16), resection (HR, 0.33), ablative therapy (HR, 0.50), TACE (HR, 0.53), and sorafenib (HR, 0.76). Although care by a hepatologist was not associated with higher odds of receiving HCC therapy, seeing this specialist within 30 days of diagnosis did lead to improved OS (HR, 0.77; 

 <.001). Additionally, evaluation by a surgeon also improved OS chances (HR, 0.72).

Evaluation by ≥1 specialist, although it resulted in higher use of active therapy, did not result in an improvement in OS (HR, 1.13; 95% CI, 1.00-1.27; 

 = 0.52); however, evaluation by a multidisciplinary tumor board did positively influence survival (HR, 0.87; 95% CI, 0.81-0.94; 

"After adjusting for tumor staging and patient comorbidities, the type of managing HCC specialist, academic affiliation, and geographic location were independently associated with receipt of curative therapy," said Serper. "Care by hepatology was not associated with higher odds of HCC therapy, but was associated with improved survival and multidisciplinary tumor boards were associated with improved survival."

Several limitations of the study led the researchers to call for additional research on the impact of tumor boards, primary the fact that the study was retrospective in nature and that there was not a control arm. Additionally, the predominantly male population and lower access to transplantation may have impacted the results.

Serper M, Kaplan DE, Taddei TH, et al. Care Delivery affects Survival in Hepatocellular Carcinoma: A ‘Real World’ Veteran Cohort Study. Presented at: AASLD Liver Meeting; Boston, Massachusetts, November 11-15, 2016. Abstract 170.

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In the observational study, treatment factors were evaluated by characterizing the utilization of HCC therapies along with care management factors, such as patient, provider, and care delivery. All patients enrolled in the study were from the VA hospital system, and were selected from an administrative database from January 2008 to December 2010. All patients were followed until December 2014. After medical chart review, there was a confirmation of 6827 cases of HCC by ICD-9CM, with 5339 confirmed by chart review. Those treated outside of the VA were excluded (n = 1126), leaving 3998 patient records for review.

Multidisciplinary tumor boards led to higher utilization of guideline-recommended curative therapies, which was associated with improved overall survival for patients with early-stage hepatocellular carcinoma.

Multidisciplinary Care Associated With Improved OS for HCC Patients

Treatment with direct-acting antiviral (DAA) therapy did not increase the risk of developing hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV) infection, according to a prospective study presented at the 2016 AASLD Liver Meeting.

In the study, a total of 3075 patients with HCV infection were followed after the initiation of DAA therapy. After 300 days of follow-up, 1.64% of patients had developed carcinoma, and after 18 months of follow-up cancer had developed in 2.5% of the patients. These rates compared favorably with patients with HCV infection who did not receive DAAs. In this historical comparators, 2.8% to 3.9% of patients with untreated HCV developed HCC.

“Patients with hepatitis C who take direct-acting antiviral medication are at no higher risk for developing liver cancer than those who do not take the medication,” said lead investigator Alfredo Alberti, MD, of the University of Padua, Padua, Italy. “There were few patients out of 3000 that developed hepatic cancer. From these results, there is no reason to change the current way you treat patients.” He added that “this is the natural history of the cancer” and mimics the population not on DAA medication.

In the study, 3381 HCV-infected patients with F3 or F4 fibrosis who were treated with DAAs were screened for the study. Overall, 306 patients were excluded: 111 had a history of HCC, 154 received a liver transplant before receiving DAAs, and 41 had a liver transplant within 4 weeks of starting DAAs. Patients were treated with different combinations of DAAs,  according to international guidelines. The most common DAA regimen used was sofosbuvir plus ledipasvir with or without ribavirin for 12 to 24 weeks (33.8%).

The mean age of patients was 58.1 years. The most frequent genotype of HCV was 1a/b (62.1%). The majority of patients had F4 cirrhosis, and a minority had severe fibrosis (F3, 27.7%). Cirrhosis was Child-Pugh (CP) score A (65.3%) and B (7%). Comorbidities were identified in approximately a third of the population, including cardiovascular disease (14.8%), diabetes (11.2%), and obesity (5.3%).

The incidence of HCC increased with cirrhosis grade, with fewer patients getting cancer with F3 fibrosis. Overall, 0.23% of patients in the F3 group developed HCC, versus 1.64% and 2.92% in the CP A and B arms, respectively. For both groups combined, the incidence rate was 1.93% for all patients with cirrhosis.

“Patients with cirrhosis taking DAA therapy should be carefully assessed for any tumor and monitored for tumor development,” Alberti reinforced.

In a univariate analysis of cirrhotic patients, AST to Platelet Ratio Index (APRI) predicted a higher HCC incidence rate (

 = .02). The incidence was 1.52% in those with an APRI score <2.5 compared with 3.27% for those with a score ≥2.5. It was found that HCC risk increase by 10% for each 1 point increase in APRI.

In relation to the virological response, the sustained viral response (SVR) was 97.2% in patients with fibrosis F3, 92.7% in patients with Child-Pugh A cirrhosis, and 80% in those with Child Pugh B cirrhosis. In the univariate analysis, those who failed to achieve SVR had a higher likelihood of developing HCC (8.38%) compared to those who responded to DAA therapy (1.55%).

In looking at the patterns of HCC development, 48.8% of patients had a single cancerous nodule, 12.2% of patients had 2 or 3 nodules, and 39% had more than 3 nodules or an infiltrative HCC. Portal thrombosis and extrahepatic metastasis were noted for 12.2% and 9.7% of patients, respectively.

When looking at these patterns in conjunction with SVR, it was found that a response to DAA greatly impacted the number of detected nodules. Those who did not respond were more likely to have >3 nodules (53.8%) compared with patients who responded (33.3%). Additionally, the time from initiation of therapy impacted morphologic patterns. When cancer was detected within 6 months of initating DAA therapy, it was more likely to be detected in >3 nodules. After 6 months, a single nodule was more likely.

“Further studies are needed to clarify these issues and identify predictive markers,” said Alberti. “Meanwhile patients treated with DAAs with advanced liver disease should continue to be closely monitored for HCC.”

Romano A, Piovesan S, Anastassopoulos G, et al. Incidence and pattern of "de novo" hepatocellular carcinoma in HCV patients treated with oral DAAs. Presented at: AASLD Liver Cancer Meeting; Boston, Massachusetts, November 11-15, 2016. Abstract 19.

Data for the study were collected using a web-based network, which included data from patients treated at 24 clinical centers located in the Veneto region of North-East Italy. Patients were prospectively monitored between January 2015 and June 2016, and those previously diagnosed with cancer were excluded from the study.

Treatment with direct-acting antiviral therapy did not increase the risk of developing hepatocellular carcinoma in patients with hepatitis C virus (HCV) infection.
 

DAAs Not Associated With Increased HCC Risk in HCV Patients

A new system for gauging the probability for hepatocellular carcinoma (HCC) recurrence following liver transplant (LT) surgery has proved successful, according to Neil Mehta, MD, a gastroenterologist and transplant hepatologist who presented the study results November 13, 2016 at the American Association for the Study of Liver Diseases annual Liver Meeting.

The study, based on historical data from UNOS, which coordinates United States transplant activities, evaluated the viability of the Risk Estimation of Tumor Recurrence After Transplant (RETREAT) system.

Results showed that the lower the RETREAT score, the better the chances of post LT survival were 3 years after LT, which confirmed the utility of the scoring system.

Tumor recurrence after LT is the most common cause of death for HCC patients. For the past 20 years, Milan criteria (1 lesion of < 5 cm, 2-3 lesions of < 3 cm) have been the standard for choosing ideal HCC LT candidates. During that period, HCC recurrence with LT has been 10% to 15% with a median survival of approximately 1 year after HCC recurrence. In search of ways to decrease tumor recurrence and better identify patients who may benefit from adjuvant therapies, researchers tested the RETREAT system.

RETREAT incorporates 3 variables that independently predict HCC recurrence: microvascular invasion (MVI), alpha-fetoprotein (AFP) at LT, and the sum of the largest viable tumor diameter and number of viable tumors on the explant.

A total of 4,218 patients were considered for study, based on UNOS data. The final cohort totaled 3,392. Patients were excluded based on unavailable explant tumor burden (n=22), no AFP within 90 days of LT (n=769), and no HCC on explant without local-regional therapy (LRT) (n=35).

Harrell’s C-index and the net reclassification index (NRI) were used to evaluate the performance of RETREAT in predicting HCC recurrence.

Median age of participants was 60, 77% were male, and 91% received LRT before LT. Median time from listing to LT was 5 months. Median AFP at LT was 9. In the explant, 13% had MVI, 30% had no viable tumor, and 15% were beyond Milan criteria. The RETREAT score was 0-1 in 56% and >4 in 12%. Researchers concluded that the post-LT survival at 3 years decreased with an increasing RETREAT score: 91% for a score of 0; 80% for a score of 3; and 58% for a score >5. However, time from recurrence to death was similar across scores. The study found that 151 patients or 4.5% developed HCC recurrence at a median of 11 months post-LT.

They concluded that “RETREAT outperformed Milan criteria in predicting post LT HCC recurrence and may have important implications for post LT HCC surveillance strategies and to help identify patients who would derive the most benefit from future adjuvant therapies.”

The larger study was based on a smaller study of roughly 1000 patients which was used to develop the RETREAT system.

Mehta N, Dodge J, Sarkar M, Roberts J, Yao F. Validation of the RETREAT score, a novel prediction index for HCC recurrence after liver transplant using the UNOS database [AASLD abstract 6].

A new system for gauging the probability for hepatocellular carcinoma recurrence following liver transplant surgery has proved successful.

Researchers Validate Novel Prediction Index for HCC After Liver Transplant

Following on their impressive success in the treatment of several other tumor types, immune-based therapies are being studied in clinical trials for hepatocellular carcinoma (HCC) and are showing promising signals of efficacy.

“Very early results from clinical trials indeed suggest a possible role for immunotherapy in the treatment of HCC," said Tim Greten, discussing research being conducted under the auspices of the National Cancer Institute (NCI). Greten, a senior investigator at the NCI’s Center for Cancer Research, Thoracic and Gastrointestinal Branch, reported these findings at the 2016 Annual Liver Meeting of the American Association for the Study of Liver Diseases.

Nonalcoholic fatty liver disease (NAFLD) has been shown to be a precursor to HCC, providing a rationale for a laboratory study examining the effects of diet on NAFLD disease. It is understood that tumor microenvironment and tumor suppressive mechanisms affect tumor growth by suppressing antitumor immunity. NAFLD is considered to play a role in metabolic predisposition to liver cancer by causing selective CD4 T lymphocyte loss. High fat diets cause hepatic C18:2 accumulation that starts the secretion of cytokines, leading to apoptosis of tumor growth and hepatocellular carcinoma.

In 1 study reviewed by Greten, mice overexpressing the MYC oncogene were split into 2 cohorts, one placed on a methionine/choline-deficient (MCD) diet which is rich in fatty acids, and the second group was given a controlled diet.

Investigators found that the percentage of CD4 T cells was lower in mice on the MCD diet versus controls; CD8 T cells remained the same in both cohorts. These findings suggest that patients with NAFLD who eat an MCD diet may “rescue” the tumor, and a controlled diet may be beneficial in tumor control, Greten reported.

In another preclinical study, in vitro and in vivo testing was performed on CD4 and CD8 T cells to examine the effects of N-acetyl cytein (NAC, also known as acetylcysteine) treatment. NAC has multiple uses, including treatment for acetaminophen overdose and to loosen thick mucus in cystic fibrosis and chronic obstructive pulmonary disease. This study had 1 control and 3 mice cohorts: MCD diet only, MCD and NAC, and an anti-CD4 group with MCD and NAC. Results indicated that NAC treatment may prevent CD4 T cell loss and increase the percentage of necrotic 7AAD+ cells.

This research suggests that in mouse models, as well as human blood and tissue samples, dysregulation of lipid metabolism in NAFLD causes a selective loss of intrahepatic CD4+, but not CD8+ T lymphocytes, leading to accelerated hepatocarcinogenesis.

Myeloid derived suppressor cells (MDSC) also were analyzed in patients, and CD14 increases were observed in patients with HCC. MDSC also inhibited natural killer (NK) cell function which was discovered through evaluating lysis and interferon-γ release. NK cells are important effectors of innate immunity, according to Greten, and the evidence from this study suggest a critical role for NK cells in the immune responses that can be measured and detected in patients with HCC.

Greten noted that these laboratory studies using mice models and patient blood at NCI provide an important foundation and will continue alongside trials exploring the clinical experience of patients with HCC.

A phase I/II proof-of-concept study is evaluating combined locoregional therapy and the anti—CTLA4 monoclonal antibody tremelimumab in HCC. The study enrolled 32 patients with biopsy-confirmed HCC with Childs Pugh A/B7 scores and Barcelona Clinical Liver Cancer stage B or C scores. Most of the participants had already received prior sorafenib (Nexavar); other previous interventions included transarterial chemoembolization (TACE; n = 11), surgery (n = 5), and ablation (n = 5). The group had a median age of 61 years (range, 36-76).

Among 23 patients treated with 10 mg/kg of tremelimumab, the combination therapy demonstrated a median time to progression of 7.4 months and median overall survival (OS) of 13.6 months, Greten said. The OS benefit was more pronounced among patients who received TACE (n = 11); the median OS was not reached, as opposed to a median OS of 10.1 months for participants who were given radiofrequency ablation (n = 12).

Additionally, 3 studies of immunotherapies in HCC all have shown positive responses and promising survival outcomes. “All 3 studies [two involving tremelimumab and 1 nivolumab] demonstrated early signals of efficacy which is a key point,” Greten stressed, in further immunotherapy development.

These results from both the laboratory and the clinic, he concluded, indicate that onco-immunotherapy is promising in HCC. Further research will focus on personalization of immunotherapy, because, as Greten stated “personalization of HCC immunotherapy will decrease expenses and prevent time lapse between diagnosis and effective treatment.”

Greten also explained how senescence is a tumor-suppressive mechanism that arrests cells at risk for malignant transformation. The NRAS biomarker is stimulated by senescence cells that release cytokines and can have destructive effects on the tissue microenvironment. The most significant of these effects is the acquisition of a senescence-associated secretory phenotype (SASP)—induced immune cells that accumulate in the liver and release CC chemokine receptor (CCR2) and immature mast cells. Senescent fibroblasts become proinflammatory cells that have the ability to promote tumor progression. The survival rate with peritumoral senescence is associated with poor survival.

Following on their impressive success in the treatment of several other tumor types, immune-based therapies are being studied in clinical trials for hepatocellular carcinoma and are showing promising signals of efficacy.

Preclinical Studies Help to Illuminate Immunotherapy's Role in HCC

Similar recurrence-free survival (RFS) was demonstrated with radiofrequency ablation (RFA) using percutaneous and laparoscopic methods for patients with hepatocellular carcinoma (HCC) who were eligible for ablation; however, improvements in overall survival (OS) were noted with the laparoscopic technique in patients matched using a propensity score, according to findings presented at the 2016 AASLD Liver Meeting.

According to lead investigator Hyuk Soo Eun, MD, laparoscopic RFA (LRFA) may contribute to a drop in recurrences, which could impact mortality. More data and patients are needed to fully validate the results, particularly in the LRFA arm. At this time, the researchers suggest that LRFA could be a better treatment option than percutaneous RFA (PRFA) to enhance the OS of patients with HCC suitable for ablation.

“One of the reasons this study is being conducted is that LRFA may have more precision, accuracy, and securing enlarged safety margin,” said Eun, from the gastroenterology department, Hepatology Division at Changnam National University Hospital in Daejeon, Korea. “It provides easier access in locating the tumor and targeting ablations compared to percutaneous RFA. There is also a reduction in microsatellite recurrence in LRFA.”

HCC incidence and mortality have increased in the past 15 years, stressing the importance of selecting the most precise therapies. To this end, greater LRFA use is warranted, according to Eun. This approach enables the treatment of HCC in difficult locations of the liver with increased accuracy compared with traditional PRFA.

The standard of care for early stage HCC is resection, liver transplantation, and RFA and/or percutaneous ethanol injection, which are all considered curative treatments. In the intermediate stage, transcatheter arterial chemoembolization (TACE) is considered the standard. In the advanced stage, sorafenib (Nexavar) is the standard of care.

In general, LRFA is more invasive than PRFA. Although hospitalization is needed in both cases, the average stay for LRFA is 3 to 5 days compared with 2 to 3 days for PRFA, according to Eun. There have been two notable studies that have compared recurrence rates or survival outcomes between LRFA and PRFA. In the first, LRFA was shown to be a better treatment options for the ablation of larger tumors. The second study showed that LRFA was an equal treatment option to PRFA for overall survival.

For the AASLD study, 244 patients with HCC were enrolled at the Changnam National University Hospital in South Korea. Patients were treated with PRFA (n = 173) or LRFA (n = 71), according to the qualifications for each procedure. The goal of the study was to compare the effectiveness of LRFA and PRFA as treatments for HCC.

Patients were enrolled between April 2005 and October 2016. All patients had recurred after treatment with TACE or hepatic resection and only minor imbalances existed in the patient characteristics between each arms. There were more patients with cirrhotic livers and higher tumor stages in the LRFA arm versus the PRFA group.

Across the full study, a difference was not observed between the 2 treatments for OS and RFS. Prior treatment with TACE was the most significant determinant of outcomes. There were 104 patients in the PRFA arm and 33 patients in the LRFA group who received prior TACE. In these patients, there also was not a significant difference between the treatment modalities.

A propensity score was developed, based on total bilirubin, background liver disease, Child Pugh classification, tumor factors of subcapsular tumor, tumor number, TNM stage, and TACE experience. There were 33 patients in each arm who matched this score. In this subgroup, there was a significant improvement in OS with LRFA versus PRFA. This improvement in survival was shown using both Kaplan Meier and Cox regression analysis, the researchers noted.

Further research will continue to assess potential differences between these treatments. Publication of the full results from the trial will be published in March 2017.

Eun HS, Lee BS, Kim SH, et al. The comparative study of percutaneous radiofrequency ablation with laparoscopic radiofrequency ablation on overall survival and recurrence of hepatocellular carcinoma. Presented at: AASLD Liver Meeting; Bonston, Massachusetts, November 11-15, 2016. Abstract 3.

Similar recurrence-free survival was demonstrated with radiofrequency ablation using percutaneous and laparoscopic methods for patients with hepatocellular carcinoma who were eligible for ablation.

Percutaneous and Laparoscopic RFA Outcomes Similar for HCC

The use of immunotherapy as a treatment for cancer is progressively increasing with a flood of recent approvals for immune checkpoint inhibitors directed against CTLA-4 and PD-1. These therapies have revolutionized cancer treatment, making immunotherapy the fourth pillar of cancer treatment.

“Immunotherapy is the perfect anti-cancer agent, more patients are being treated with immunotherapy and it continues to increase,” stated Drew Pardoll, MD, PhD, John Hopkins University, at the AASLD Liver Meeting. Discovering ways to look at patients’ endogenous immune systems can lead to treating patients with the right type of immunotherapy by targeting, detecting, and destroying cancer cells, which will be important as these approaches are explored in hepatocellular carcinoma (HCC).

Various immune checkpoints that appear to regulate T‐cell activity have been identified, including cytotoxic T-lymphocyte antigen 4 (CTLA‐4), programmed cell death protein 1 (PD‐1), and lymphocyte activation gene 3 (LAG‐3). Checkpoints are stimulatory and inhibitory signals that regulate the duration and level of the immune response. The inhibitory immune checkpoints act like brakes on the immune response. In this case, they block a signal that would prevent activated T‑cells from attacking the cancer.

The checkpoint inhibitor that is furthest along in development for HCC is nivolumab (Opdivo), a human IgG4 anti—PD‑1 monoclonal antibody. In an expansion cohort of the CheckMate-040 study trial, the agent was explored in 4 groups of patients with HCC, all of whom received nivolumab at 3 mg/kg every 2 weeks: patients without hepatitis who had not received or were intolerant to sorafenib (n = 54); participants who had progressed after receiving sorafenib (n = 58); patients who were infected with hepatitis C (n = 51); and individuals who were infected with hepatitis B (n = 51).

The response rate did not differ by PD-L1 expression status, as assessed by immunohistochemistry on ≥1% versus <1% of tumor cells. As such, there is a still a need to uncover a biomarker to determine which patients respond best to this approach. At this point, this is an important area of research that will help shape the future age of immunotherapy.

It is assumed that tumor specific T cells are the primary executor of anti-tumor immunity; however, there is still little known about the diversity and nature of tumor antigens recognized by a patient’s endogenous immune system. As a result, studies are attempting to better understand other antigens that can be used to help predict response.

New technologies are beginning to advance these research efforts, such as rapid exome sequencing. This approach is adding to the understanding of adaptive immunity having a genetic basis for diversity. Not only does the mutational load appear to be tied to immunotherapy response but also the number and types of antigens present.

Across a handful of small studies, DNA mismatch repair has proved effective at determining response to immunotherapy. Mismatch repair-deficient tumors harbor thousands of mutations that may produce neoantigens that can be recognized and targeted by T cells. This biomarker of response was tested in a study looking at the PD-1 inhibitor pembrolizumab (Keytruda) in patients with gastrointestinal cancers, which was conducted at Johns Hopkins. In studies exploring this approach, response rates have ranged between 45% and 60%.

In addition to this approach, T‑cells with individual clone types have been identified and studied. In one analysis, 100 clones were reviewed that had significant changes between pre-treatment and pre-operation timepoints. Ninety‑four of these were significantly increased following anti‑PD‑1 therapy. These combined markers could help personalize care in the future.

At John Hopkins School of Medicine, immunofluorscopy is being utilized for immunotherapy research in cancer. One study utilizing this approach focused on CTLA-4 and PD-1. The researchers used multiplex immunofluorescent panels to review melanoma for CD8 and Foxp3 regulatory T‑cells, and found that PD-L1 is expressed predominantly on melanocytes. This finding could allow researchers to better detect, target, and personalize immunotherapy, Pardoll said. 

Further experiments continue to be conducted in mice models, which are the closest proxy to the human immune system. These mice models can be used to test hypotheses for treatment and to develop biomarkers. As biomarker research continues to advanced, future immunotherapies may also be considered targeted therapy.

The objective response rate (ORR) was 16% among 214 patients who participated in the expansion cohort of the study. Among the 35 patients who responded, 33 had partial responses and 2 experienced a complete response. Another 111 patients had stable disease. ORRs were similar across the groups. The ORR ranged from 12% for patients who had been infected with hepatitis B to 20% for uninfected patients who were sorafenib naïve or intolerant.

The use of immunotherapy as a treatment for cancer is progressively increasing with a flood of recent approvals for immune checkpoint inhibitors directed against CTLA-4 and PD-1.

Biomarkers Define Future Age of Immunotherapy in Cancer

A supplemental new drug application (sNDA) was recently submitted to the FDA for the use of regorafenib (Stivarga) in patients with unresectable hepatocellular carcinoma (HCC) who progress on standard first-line treatment with sorafenib (Nexavar).

The sNDA is based on the phase III RESORCE trial,

 in which regorafenib reduced the risk of death by 38% versus placebo in patients with HCC who progressed on frontline sorafenib (HR, 0.62; 

 <.001); however, it remains unclear how regorafenib works to inhibit HCC growth after sorafenib failure.

In a poster presented at the 2016 Annual Liver Meeting of the American Association for the Study of Liver Diseases, researchers summarized their efforts to further evaluate the effects of regorafenib on sorafenib-resistant HCC cells, including the role of suppressing the ERK signaling pathway.

Drs Tomimo Hashiba and Taro Yamashita from Kanazawa University Hospital in Ishikawa, Japan, and colleagues obtained 2 HCC cell lines (Huh1 and Huh7) and 2 primary HCC cells from a surgically resected specimen. These cells were cultured routinely. Sorafenib (5-10 mM) was supplemented for 3 months to generate sorafenib-resistant clones in Huh1and Huh7.

There were differences in the 2 cell lines. KH cell had an etiology of hepatitis C, results of 10 ng/mL for the biomarker α-fetoprotein (AFP), and the patient’s prior treatment was resection and adjuvant sorafenib for 2 years. KM cells were sorafenib naïve, had an etiology of hepatitis B, results of 39 ng/mL AFP and pretreatment of transcatheter arterial chemoembolization and radiofrequency ablation.

Whole exome sequence was performed to detect mutations. Only the KH cell line was positive for 

 pathway related genes, and some mutation was found in only KH.

“We evaluated the mutations of all genes by whole exome sequence analysis and tried to pick up genes specifically mutated in sorafenib-resistant cells. KM, Huh1, and Huh7 cells were derived from HCC patients who did not receive sorafenib, so genes specifically mutated in KH might be related to the sorafenib resistance,” said Yamashita.

Protein expression of phospho-AKT (Ser473), -STAT3, and -ERK was evaluated by Western blotting and suggested sorafenib had no effect on suppression of AKT, ERK, and STAT3 signaling pathways. In contrast, regorafenib suppressed the phosporphorylation of STAT3 and ERK signaling in KH cells.

“STAT3 and downstream genes were not mutated in sorafenib-resistant KH cells,” said Yamashita. “Potential target genes such as 

were also evaluated, but were found not mutated.” When sensitivity was tested in vitro, KH cells showed chemosensitivities to regorafenib but not to sorafenib.

A subcutaneous xenotransplantation model was used to evaluate the efficacy of orally administered sorafenib (30 mg/kg/day) or regorafenib (20 mg/kg/day) on sorafenib-resistant clones in vivo. Although all sorafenib-resistant clones (KH, sorafenib-resistant Huh1 and Huh7 cells) showed frequent missense/nonsense mutations compared with the naive clones, no common mutations including sorafenib target genes 

were detected among all sorafenib-resistant clones.

The researchers concluded that regorafenib did inhibit the growth of sorafenib resistant HCC cells potentially through the suppression of the ERK signaling. However, regorafenib and sorafenib showed similar antitumor effects in sorafenib-naïve HCC cells. Just as the phase III RESORCE trial showed promising data on overall survival, the efficacy of regorafenib on the sorafenib-resistant clones suggests potential utility as a second-line treatment in HCC.

Data from this study suggests regorafenib works to inhibit HCC growth after sorafenib failure and Hashiba said, “Tumor growth and suppression with regorafenib may be occurring through the ERK signaling pathway and possibly other pathways. There were cells from only 2 patients in this study, therefore no conclusions could be made at this time.”

Yamashita agreed, “This data suggests…regorafenib may inhibit the tumor in sorafenib-resistant as well as sorafenib-naïve tumors.” Further research plans are to identify biomarkers that potentially select HCC patients who will have a survival benefit through treatment with regorafenib after sorafenib failure.

Regorafenib is currently approved by the FDA for the treatment of patients with metastatic colorectal cancer and advanced gastrointestinal stromal tumors.

Bruix J, Merle P, Granito A, et al. Efficacy and safety of regorafenib versus placebo in patients with hepatocellular carcinoma (HCC) progressing on sorafenib: results of the international, randomized phase 3 RESORCE trial. Presented at: 2016 World Congress on GI Cancer; June 28 - July 2, 2016; Barcelona, Spain. Abstract LBA03.

Tomomi Hashiba T, Taro Yamashita T, Hikari Okada H, et al. Regorafenib inhibits ERK signaling and suppresses the growth of sorafenib-resistant cells in human hepatocellular carcinoma. Presented at: 2016 AASLD Liver Meeting; November 11-15, 2016; Boston, MA. Abstract 1953.

Although regorafenib treatment suppressed the subcutaneous tumor growth of sorafenib-resistant Huh7 clones with significantly prolonged overall survival (

 = .014), regorafenib and sorafenib showed similar antitumor effects in naïve Huh7 cells.

Efforts are under way to further evaluate the effects of regorafenib on sorafenib-resistant HCC cells, including the role of suppressing the ERK signaling pathway.

Marilyn White