TP53/mTORC1-mediated bidirectional regulation of PD-L1 modulates immune evasion in hepatocellular carcinoma.

BACKGROUND: Immunotherapy has facilitated great breakthroughs in the treatment of hepatocellular carcinoma (HCC). However, the efficacy and response rate of immunotherapy are limited and vary among different patients with HCC. TP53 mutation substantially affects the expression of immune checkpoint molecules in multiple cancers. However, the regulatory relationship between programmed death ligand 1 (PD-L1) and TP53 is poorly studied in HCC. We aimed to elucidate the regulatory mechanism of PD-L1 in HCC with different TP53 statuses and to assess its role in modulating immune evasion in HCC. METHODS: HCC mouse models and cell lines with different TP53 statuses were constructed. PD-L1 levels were detected by PCR, western blotting and flow cytometry. RNA-seqencing, immunoprecipitation, chromatin immunoprecipitation and transmission electron microscopy were used to elucidate the regulatory mechanism in HCC with different TP53 status. HCC mouse models and patient with HCC samples were analyzed to demonstrate the preclinical and clinical significance of the findings. RESULTS: We report that loss of p53 promoted PD-L1 expression and reduced CD8+ T-cell infiltration in patient with HCC samples and mouse models. Mammalian target of rapamycin (mTOR) pathway was activated in p53-loss-of-function HCC or after knocking down TP53. The transcription factor E2F1 was found to bind to the p53 protein in TP53 wild-type HCC cells, and inhibiting mammalian target of rapamycin complex 1 (mTORC1) disrupted this binding and enhanced E2F1 translocation to the nucleus, where it bound to the PD-L1 promoter and transcriptionally upregulated PD-L1. In p53-loss-of-function HCC cells, autophagosomes were activated after mTORC1 suppression, promoting the degradation of PD-L1 protein. The combination of mTOR inhibitor and anti-PD-L1 antibody enhanced CD8+ T-cell infiltration and tumor suppression in TP53 wild-type HCC mouse models, but no benefit was observed in p53-loss-of-function HCC mouse models. In patients with TP53 wild-type HCC, PD-L1 levels were significantly higher in the high E2F1 group than in the low E2F1 group, and the low E2F1 level group had significantly superior survival. CONCLUSION: We revealed the bidirectional regulatory mechanism of PD-L1 mediated by TP53/mTORC1 in HCC. The combination of mTOR inhibitor and anti-PD-L1 antibody could be a novel precise immunotherapy scheme for TP53 wild-type HCC.

E2F7 promotes mammalian target of rapamycin inhibitor resistance in hepatocellular carcinoma after liver transplantation.

The mammalian target of rapamycin (mTOR) pathway is frequently deregulated and has critical roles in cancer progression. mTOR inhibitor has been widely used in several kinds of cancers and is strongly recommended in patients with hepatocellular carcinoma (HCC) after liver transplantation (LT). However, the poor response to mTOR inhibitors due to resistance remains a challenge. Hypoxia-associated resistance limits the therapeutic efficacy of targeted drugs. The present study established models of HCC clinical samples and cell lines resistance to mTOR inhibitor sirolimus and screened out E2F7 as a candidate gene induced by hypoxia and promoting sirolimus resistance. E2F7 suppressed mTOR complex 1 via directly binding to the promoter of the TSC1 gene and stabilizes hypoxia-inducible factor-1α activating its downstream genes, which are responsible for E2F7-dependent mTOR inhibitor resistance. Clinically, low E2F7 expression could be an effective biomarker for recommending patients with HCC for anti-mTOR-based therapies after LT. Targeting E2F7 synergistically inhibited HCC growth with sirolimus in vivo. E2F7 is a promising target to reverse mTOR inhibition resistance. Collectively, our study points to a role for E2F7 in promoting mTOR inhibitor resistance in HCC and emphasizes its potential clinical significance in patients with HCC after LT.

Long-term outcomes of deceased donor liver transplantation in hepatocellular carcinoma patients with portal vein tumor thrombus: A multicenter study.

BACKGROUND: The incidence of portal vein tumor thrombus (PVTT) has been reported to be as high as approximately 10%-40% in patients with hepatocellular carcinoma (HCC). The long-term prognosis of deceased donor liver transplantation (DDLT) in HCC patients with PVTT remains unknown. METHODS: Data of 961 HCC patients who underwent DDLT between 2015 and 2018 in six centers were analyzed. Based on the Milan criteria (MC) and Cheng's classification of PVTT, the patients were divided into 4 groups: within MC, beyond MC without PVTT, type 1 PVTT, and type 2 PVTT groups. RESULTS: 489 (50.9%) were within the MC, 296 (30.8%) beyond the MC but without PVTT, 83 (8.6%) type 1 PVTT, and 93 (9.7%) type 2 PVTT. Kaplan-Meier analysis showed that type 1 or 2 PVTT patients with alpha-fetoprotein (AFP) ≤ 100 ng/mL had overall survival (OS) similar to that of patients within the MC (P = 0.957), and superior OS (P = 0.003 and 0.009) and recurrence-free survival (RFS) (P = 0.038 and <0.001) than those of patients beyond the MC and PVTT patients with AFP > 100 ng/mL. Multivariable Cox-regression analysis identified type 1 and 2 PVTT to be independent risk factor for RFS [hazard ratio (HR) 1.523 95% confidence interval (CI) 1.162-1.997, P = 0.002], but not for OS (HR 1.283, 95%CI 0.922-1.786, P = 0.139). CONCLUSION: HCC patients with type 1 or 2 PVTT may be acceptable candidates for DDLT. To achieve better outcomes, preoperative AFP levels should be seriously considered when selecting patients with PVTT for DDLT.

Regulatory T Cell Therapy Following Liver Transplantation.

Liver transplantation (LT) is considered the gold standard of curative treatment for patients with end-stage liver disease or nonresectable hepatic malignant tumors. Rejection after LT is the main nontechnical factor affecting the prognosis of recipients. Medical and surgical advances, combined with improved immunosuppression with drugs such as calcineurin inhibitors (CNIs), have contributed to an increase in 1-year graft survival to around 80%. However, medium- and long-term improvements in LT outcomes have lagged behind. Importantly, CNIs and other classical immunosuppressive drugs are associated with significant adverse effects, including malignancies, cardiovascular disease, and severe renal dysfunction. Immunomodulation using regulatory T cells (Tregs) is emerging as a promising alternative to classical immunosuppression. Since their discovery, the immunomodulatory effects of Tregs have been demonstrated in a range of diseases. This has rejuvenated the interest in using Tregs as a therapeutic strategy to induce immune tolerance after LT. In this review, we first summarize the discovery and development of Tregs. We then review the preclinical data supporting their production, mechanism of action, and therapeutic efficacy followed by a summary of relevant clinical trials. Finally, we discuss the outstanding challenges of Treg therapy and its future prospects for routine use in LT.

Impact of Surveillance in Chronic Hepatitis B Patients on Long-Term Outcomes After Curative Liver Resection for Hepatocellular Carcinoma.

BACKGROUND: Clinical guidelines recommend surveillance in high-risk population to early detect hepatocellular carcinoma (HCC), when curative treatment such as liver resection can be applied. However, it is largely unknown whether surveillance would provide long-term survival benefits to these high-risk patients who have received curative liver resection for HCC. METHODS: A prospectively maintained database on patients with chronic hepatitis B infection who underwent curative liver resection for HCC from 2003 to 2014 was reviewed. Patients' overall survival and recurrence were compared between the groups of patients whose HCCs were diagnosed by surveillance or non-surveillance, as well as between the groups of patients operated in the first (2003-2008) and second (2009-2014) 6-year periods. RESULTS: Of 1075 chronic hepatitis B patients with HCC, 452 (42.0%) patients were diagnosed by preoperative surveillance. Compared with the non-surveillance group, the OS and RFS rates were significantly better in the surveillance group (both P < 0.001). Surveillance was associated with a 55% decrease in the overall survival risk and a 48% decrease in the recurrence risk (HR 0.45, 95% CI 0.38-0.53, and HR 0.52, 95% CI 0.44-0.61). Compared with the first period, a significant reduction of 12% and 19% in the overall death and recurrence risks, respectively, was observed in the second period (HR 0.88, 95% CI 0.78-0.97, and HR 0.81, 95% CI 0.70-0.95). CONCLUSION: Surveillance for HCC was associated with favorable long-term overall and recurrence-free survival rates after curative liver resection of HCC in patients with chronic hepatitis B.

Association between body mass index and postoperative morbidity after liver resection of hepatocellular carcinoma: A multicenter study of 1,324 patients.

BACKGROUND: Morbidity remains a common problem following hepatic resection. The aim of this study was to investigate the association between preoperative body mass index (BMI) and morbidity in patients undergoing liver resection for hepatocellular carcinoma (HCC). METHODS: Patients were divided into three groups according to preoperative BMI: low-BMI (≤18.4 kg/m2), normal-BMI (18.5-24.9 kg/m2) and high-BMI (≥25.0 kg/m2). Baseline characteristics, operative variables, postoperative 30-day mortality and morbidity were compared. Univariable and multivariable analyses were performed to identify independent risk factors associated with postoperative morbidity. RESULTS: Among 1324 patients, 108 (8.2%), 733 (55.4%), and 483 (36.5%) were low-BMI, normal-BMI, and high-BMI, respectively. There were no differences in postoperative 30-day mortality among patients based on BMI (P = 0.199). Postoperative 30-day morbidity was, however, higher in low-BMI and high-BMI patients versus patients with a normal-BMI (33.3% and 32.1% vs. 22.9%, P = 0.018 and P < 0.001, respectively). Following multivariable analysis low-BMI and high-BMI remained independently associated with an increased risk of postoperative morbidity (OR: 1.701, 95%CI: 1.060-2.729, P = 0.028, and OR: 1.491, 95%CI: 1.131-1.966, P = 0.005, respectively). Similar results were noted in the incidence of postoperative 30-day surgical site infection (SSI). CONCLUSION: Compared with normal-BMI patients, low-BMI and high-BMI patients had higher postoperative morbidity, including a higher incidence of SSI after liver resection for HCC.

Preoperative transcatheter arterial chemoembolization for surgical resection of huge hepatocellular carcinoma (≥ 10 cm): a multicenter propensity matching analysis.

BACKGROUND AND AIMS: Surgical resection for hepatocellular carcinoma (HCC) is potentially curative, but long-term survival remains unsatisfactory. There is currently no effective neoadjuvant or adjuvant therapy for HCC. We sought to evaluate the impact of preoperative transcatheter arterial chemoembolization (TACE) on long-term prognosis after surgical resection of huge HCCs (≥ 10 cm). METHODS: Using a multicenter database, consecutive patients who underwent curative-intent resection for huge HCC without macrovascular invasion between 2004 and 2014 were identified. The association between preoperative TACE with perioperative outcomes, long-term overall survival (OS), and recurrence-free survival (RFS) was assessed before and after propensity score matching (PSM). RESULTS: Among the 377 enrolled patients, 88 patients (23.3%) received preoperative TACE. The incidence of perioperative mortality and morbidity was comparable among patients who did and did not undergo preoperative TACE (3.4% vs. 2.4%, p= 0.704, and 33.0% vs. 31.1%, p= 0.749, respectively). PSM analysis created 84 matched pairs of patients. In examining the entire cohort as well as the PSM cohort, median OS (overall cohort: 32.8 vs. 22.3 months, p= 0.035, and PSM only: 32.8 vs. 18.1 months, p= 0.023, respectively) and RFS (12.9 vs. 6.4 months, p= 0.016, and 12.9 vs. 4.1 months, p= 0.009, respectively) were better among patients who underwent preoperative TACE vs. patients who did not. After adjustment for other confounding factors on multivariable analyses, preoperative TACE remained independently associated with a favorable OS and RFS after the resection of huge HCC. CONCLUSION: Preoperative TACE did not increase perioperative morbidity or mortality, yet was associated with an improved OS and RFS after liver resection of huge HCC (≥ 10 cm).

Association of family history with long-term prognosis in patients undergoing liver resection of HBV-related hepatocellular carcinoma.

BACKGROUND: Family history is a risk factor for the development of hepatocellular carcinoma (HCC). The aim of the current study was to investigate the association between family history of HCC and long-term oncologic prognosis among patients undergoing curative liver resection for hepatitis B virus (HBV)-related HCC. METHODS: Patients who underwent curative liver resection of HBV-related HCC between 2003 and 2013 were consecutively enrolled. Family history was defined as a self-reported history of HCC in a first-degree relative. Propensity score matching (PSM) and multivariable Cox-regression analyses were performed to compare overall survival (OS) and recurrence-free survival (RFS) among patients with and without a family history. RESULTS: Among 1,112 patients, 183 (16.5%) patients had a family history of HCC. Using PSM, 179 pairs of patients with and without a family history were created that had no differences in the baseline characteristics and operative variables. On matched analysis, family history was associated with decreased OS and RFS after curative-intent resection of HBV-related HCC in the propensity matching cohort (P=0.042 and 0.006, respectively). On multivariable Cox-regression analyses, a family history of HCC was associated with decreased OS (HR: 1.574; 95% CI: 1.171-2.116; P=0.003) and RFS (HR: 1.534; 95% CI: 1.176-2.002; P=0.002) after adjusting for other prognostic risk factors. CONCLUSIONS: Family history was associated with decreased OS and RFS rates among patients undergoing curative liver resection of HBV-related HCC.

Long-Term Survival Outcomes After Liver Resection for Binodular Hepatocellular Carcinoma: A Multicenter Cohort Study.

BACKGROUND: The long-term prognosis after liver resection for multinodular (≥3 nodules) hepatocellular carcinoma (HCC) is generally considered to be unfavorable. However, the role of liver resection for binodular HCC is less investigated. SUBJECTS, MATERIALS, AND METHODS: From a multicenter database, consecutive patients who underwent curative-intent liver resection for binodular HCC and without macrovascular invasion between 2003 and 2015 were retrospectively reviewed. Patients' clinical variables as well as perioperative and long-term survival outcomes were analyzed. Univariable and multivariable analyses were performed to identify the risk factors associated with overall survival (OS) and recurrence-free survival (RFS) after curative resection. RESULTS: Of 263 enrolled patients, the perioperative 30-day mortality and morbidity rates were 1.5% and 28.5%. The 1-, 3-, and 5-year OS and RFS rates were 81.5%, 52.4%, and 39.1% and 57.1%, 35.8%, and 26.6%, respectively. Multivariable Cox-regression analyses identified preoperative alpha-fetoprotein level >400 µg/L, tumor size with a sum of two nodules >8 cm, tumor size ratio of large/small nodule >1.5 (asymmetrical proportion), unilateral hemiliver distribution of two nodules, distance of ≤3 cm between two nodules, and microvascular invasion in any nodule as independent risk factors associated with decreased OS and RFS. CONCLUSION: Liver resection was safe and feasible in patients with binodular HCC, with acceptable perioperative and long-term outcomes. Sum of two tumor sizes, size ratio and distribution, and distance between two nodules were independent risk factors associated with long-term survival outcomes after surgery. These results may guide clinicians to make individualized surgical decisions and estimate long-term prognosis for these patients. IMPLICATIONS FOR PRACTICE: Liver resection was safe and feasible in patients with binodular hepatocellular carcinoma, with acceptable perioperative and long-term outcomes. The sum of two tumor sizes, the size ratio and distribution of the two nodules, and the distance between two nodules were independent risk factors associated with long-term overall survival and recurrence-free survival after liver resection. The results of this study may guide clinicians to make individualized surgical decisions, estimate long-term prognosis, and plan recurrence surveillance and adjuvant therapy for these patients.

Preoperative prealbumin level as an independent predictor of long-term prognosis after liver resection for hepatocellular carcinoma: a multi-institutional study.

BACKGROUND: Serum prealbumin is a sensitive and stable marker for nutritional status and liver function. Whether preoperative prealbumin level is associated with long-term prognosis in patients undergoing liver resection for hepatocellular carcinoma (HCC) is unclear. METHODS: Patients who underwent liver resection for HCC between 2001 and 2014 at six institutions were enrolled. These patients were divided into the low and normal prealbumin groups using a cut-off value of 170 mg/L for preoperative prealbumin level. The overall survival (OS) and recurrence-free survival (RFS) were compared between them. RESULTS: In 1483 patients, 437 (29%) had a low prealbumin level. The 3- and 5-year OS and RFS rates of patients in the low-prealbumin group were 57 and 31%, and 40 and 20%, respectively, which were significantly poorer than those in the normal-prealbumin group (76 and 43%, and 56 and 28%, respectively, both p < 0.001). Multivariable Cox-regression analyses revealed that preoperative prealbumin level was an independent predictor of OS (HR, 1.45, 95% CI: 1.24-1.70, p <0.001) and RFS (HR, 1.28, 95% CI: 1.10-1.48, p <0.001). CONCLUSIONS: Preoperative prealbumin level could be used in predicting long-term prognosis for patients undergoing liver resection for HCC.

Liver resection is justified for multinodular hepatocellular carcinoma in selected patients with cirrhosis: A multicenter analysis of 1,066 patients.

BACKGROUND: The role of liver resection for multinodular (≥3 nodules) hepatocellular carcinoma (HCC) remains unclear, especially among patients with severe underlying liver disease. We sought to evaluate surgical outcomes among patients with cirrhosis and multinodular HCC undergoing liver resection. METHODS: Using a multicenter database, outcomes among cirrhotic patients who underwent curative-intent resection of HCC were examined stratified according to the presence or absence of multinodular disease. Perioperative mortality and morbidity, as well as overall survival (OS) and recurrence-free survival (RFS) were compared between the two groups. RESULTS: Among 1066 cirrhotic patients, 906 (85.0%) had single- or double-nodular HCC (the non-multinodular group), while 160 (15.0%) had multinodular HCC (the multinodular group). There were no differences in postoperative 30-day mortality and morbidity among non-multinodular versus multinodular patients (1.8% vs. 1.9%, P = 0.923, and 36.0% vs. 39.4%, P = 0.411, respectively). In contrast, 5-year OS and RFS of multinodular patients were worse compared with non-multinodular patients (34.6% vs. 58.2%, and 24.7% vs. 44.5%, both P < 0.001). On multivariable analyses, tumor numbers ≥5, total tumor diameter ≥8 cm and microvascular invasion were independent risk factors for decreased OS and RFS after resection of multinodular HCC in cirrhotic patients. CONCLUSIONS: Liver resection can be safely performed for multinodular HCC in the setting of cirrhosis with an overall 5-year survival of 34.6%. Tumor number ≥5, total tumor diameter ≥8 cm and microvascular invasion were independently associated with decreased OS and RFS after resection in cirrhotic patients with multinodular HCC.