405 Background: Hepatocellular carcinoma (HCC) is the fastest rising cause of cancer mortality in the United States. Although clinical guidelines recommend ultrasound (U/S), with or without the serum biomarker alpha fetoprotein (AFP) for HCC surveillance in at-risk patients, only 24% of patients adhere to surveillance and only one-third of HCCs are detected before developing symptoms. A multi-target HCC blood-based test (mt-HBT) was recently shown to have promising sensitivity for early HCC detection and may help improve surveillance adherence given its blood-based nature. Our objective was to evaluate the comparative clinical effectiveness of mt-HBT with the current standard-of-care surveillance strategy in patients with cirrhosis. Methods: We simulated a virtual trial by developing a microsimulation model of the natural history of HCC in patients with compensated (Child Pugh A) cirrhosis over a 30-year horizon. To inform model parameters, we used published data on tumor progression, competing risks of mortality, and real-world HCC surveillance adherence. Test performance characteristics were informed by a network meta-analysis. We simulated the life course of 51-year-old patients with cirrhosis and compared no surveillance with biannual surveillance using (1) AFP only, (2) U/S only, (3) U/S+AFP, (4) mt-HBT, and (5) mt-HBT with improved adherence. We assumed a blood-based test—without U/S—would improve surveillance adherence by 10% compared with current adherence (̃4% absolute improvement). Results: Per 100,000 cirrhosis patients, mt-HBT detected 6,220 more early-stage HCC than no surveillance, 2,250 (+57%) more than AFP, 1080 (+21%) more than U/S, and 200 (-3%) less than U/S+AFP. mt-HBT with improved adherence detected 210 (+3%) more early-stage HCC than U/S+AFP (Table). The remaining HCC cases were either symptomatic or the patients died per other competing causes prior to detection. The number of screening tests needed to detect one HCC were 296 for AFP, 287 for U/S, 253 for U/S+AFP, 254 for mt-HBT and 262 for mt-HBT with improved adherence. The number of diagnostic MRI/CT needed to detect one HCC were 40 for AFP, 38 for U/S, 45 for U/S+AFP, 37 for mt-HBT, and 38 for mt-HBT with improved adherence. Conclusions: mt-HBT detects more early-HCC cases than U/S and similar number of early-HCC cases with U/S+AFP. By decreasing surveillance barriers and increasing adherence, mt-HBT could improve early HCC detection and could be promising option for HCC surveillance in patients with cirrhosis. [Table: see text]
Novel and emerging targets for cholangiocarcinoma progression: therapeutic implications
Prostate‐specific membrane antigen (PSMA) is a validated target for molecular diagnostics and targeted radionuclide therapy. Our purpose was to evaluate PSMA expression in hepatocellular carcinoma (HCC), cholangiocarcinoma (CCA), and hepatic adenoma (HCA); investigate the genetic pathways in HCC associated with PSMA expression; and evaluate HCC detection rate with 68Ga‐PSMA‐11 positron emission tomography (PET). In phase 1, PSMA immunohistochemistry (IHC) on HCC (n = 148), CCA (n = 111), and HCA (n = 78) was scored. In a subset (n = 30), messenger RNA (mRNA) data from the Cancer Genome Atlas HCC RNA sequencing were correlated with PSMA expression. In phase 2, 68Ga‐PSMA‐11 PET was prospectively performed in patients with treatment‐naïve HCC on a digital PET scanner using cyclotron‐produced 68Ga. Uptake was graded qualitatively and semi‐quantitatively using standard metrics. On IHC, PSMA expression was significantly higher in HCC compared with CCA and HCA (P < 0.0001); 91% of HCCs (n = 134) expressed PSMA, which principally localized to tumor‐associated neovasculature. Higher tumor grade was associated with PSMA expression (P = 0.012) but there was no association with tumor size (P = 0.14), fibrosis (P = 0.35), cirrhosis (P = 0.74), hepatitis B virus (P = 0.31), or hepatitis C virus (P = 0.15). Overall survival tended to be longer in patients without versus with PSMA expression (median overall survival: 4.2 vs. 1.9 years; P = 0.273). FGF14 (fibroblast growth factor 14) mRNA expression correlated positively (rho = 0.70; P = 1.70 × 10‐5) and MAD1L1 (Mitotic spindle assembly checkpoint protein MAD1) correlated negatively with PSMA expression (rho = −0.753; P = 1.58 × 10‐6). Of the 190 patients who met the eligibility criteria, 31 patients with 39 HCC lesions completed PET; 64% (n = 25) lesions had pronounced 68Ga‐PSMA‐11 standardized uptake value: SUVmax (median [range] 9.2 [4.9‐28.4]), SUVmean 4.7 (2.4‐12.7), and tumor‐to‐liver background ratio 2 (1.1‐11). Conclusion: Ex vivo expression of PSMA in neovasculature of HCC translates to marked tumor avidity on 68Ga‐PSMA‐11 PET, which suggests that PSMA has the potential as a theranostic target in patients with HCC.
Sulfatase-2 Regulates Liver Fibrosis through the TGF-β Signaling Pathway
Transforming growth factor-β (TGF-β) activates hepatic stellate cells (HSCs), which drive liver fibrosis via the production and deposition of extracellular matrix (ECM). We aimed to elucidate the mechanistic role of sulfatase-2 (SULF2) in liver fibrosis. To this end, we induced liver fibrosis in wild-type (WT) and SULF2 knockout (Sulf2-KO) mice (6–8 weeks-old) via bile duct ligation (BDL), intraperitoneal injection of carbon tetrachloride (CCl4) or thioacetamide (TAA). The levels of fibrosis in the liver sections were assessed via Sirius red and Masson’s trichrome staining, immunohistochemistry and immunoblotting for α-smooth muscle actin (α-SMA) and hydroxyproline. To evaluate the interaction between TGF-β and SULF2, we transfected human HSCs with scrambled control shRNA and shRNA constructs targeting SULF2 and measured α-SMA expression following treatment with TGF-β1 ligand. We show here that knockout of SULF2 significantly decreases collagen content, as well as bands of bridging fibrosis, as demonstrated by Sirius red, Masson’s trichrome and α-SMA staining after BDL, CCl4 and TAA injection in Sulf2-KO versus WT mice. In all three models of liver fibrosis, we observed significantly lower levels of hydroxyproline in the Sulf2-KO mice compared to the WT mice. HSCs with reduced levels of SULF2 failed to significantly express α-SMA and collagen type I following treatment with TGF-β1. Furthermore, SULF2 co-localizes with TGFBR3 and the in vitro knockdown of SULF2 in HSCs decreases the release of TGF-β1 from TGFBR3. Together, these data suggest that SULF2 regulates liver fibrosis via the TGF-β signaling pathway. Pharmacologic inhibition of SULF2 may represent a novel therapeutic approach to improve liver fibrosis.
Therapeutic Underuse and Delay in Hepatocellular Carcinoma: Prevalence, Associated Factors, and Clinical Impact
Prognosis of hepatocellular carcinoma (HCC) could be affected by lack of or delayed therapy. We aimed to characterize the prevalence, correlates, and clinical impact of therapeutic underuse and delay in patients with HCC. Patients with HCC diagnosed between 2010 and 2017 were analyzed from the United States National Cancer Database. Logistic regression analysis identified factors associated with no and delayed (>90 days after diagnosis) HCC treatment. Cox proportional hazards regression with landmark analysis assessed the association between therapeutic delay and overall survival (OS), accounting for immortal time bias. Of 116,299 patients with HCC, 24.2% received no treatment and 18.4% of treated patients had delayed treatment. Older age, Black, Hispanic, lower socioeconomic status, earlier year of diagnosis, treatment at nonacademic centers, Northeast region, increased medical comorbidity, worse liver dysfunction, and higher tumor burden were associated with no treatment. Among treated patients, younger age, Hispanic, Black, treatment at academic centers, West region, earlier tumor stage, and receipt of noncurative treatment were associated with treatment delays. In multivariable Cox regression with a landmark of 150 days, patients with and without treatment delays had similar OS (adjusted hazard ratio [aHR], 1.01; 95% confidence interval [CI], 0.98‐1.04) with a median survival of 33.7 vs. 32.1 months, respectively. However, therapeutic delay was associated with worse OS in patients who had tumor, nodes, and metastases (TNM) stage 1 (aHR, 1.06; 95% CI, 1.01‐1.11) or received curative treatment (aHR, 1.12; 95% CI, 1.05‐1.18). Conclusion: One‐fourth of patients with HCC receive no therapy and one‐fifth of treated patients experience treatment delays. Both were associated with demographic, socioeconomic, and clinical characteristics of patients as well as facility type and region. The association between therapeutic delay and survival was stage and treatment dependent.
Synergistic combination of cytotoxic chemotherapy and cyclin‐dependent kinase 4/6 inhibitors in biliary tract cancers
Abstract Background and aims Biliary tract cancers (BTCs) are uncommon, but highly lethal, gastrointestinal malignancies. Gemcitabine/cisplatin is a standard‐of‐care systemic therapy, but has a modest impact on survival and harbors toxicities, including myelosuppression, nephropathy, neuropathy, and ototoxicity. Whereas BTCs are characterized by aberrations activating the cyclinD1/cyclin‐dependent kinase (CDK)4/6/CDK inhibitor 2a/retinoblastoma pathway, clinical use of CDK4/6 inhibitors as monotherapy is limited by lack of validated biomarkers, diffident preclinical efficacy, and development of acquired drug resistance. Emerging studies have explored therapeutic strategies to enhance the antitumor efficacy of CDK4/6 inhibitors by the combination with chemotherapy regimens, but their mechanism of action remains elusive. Approach and results Here, we report in vitro and in vivo synergy in BTC models, showing enhanced efficacy, reduced toxicity, and better survival with a combination comprising gemcitabine/cisplatin and CDK4/6 inhibitors. Furthermore, we demonstrated that abemaciclib monotherapy had only modest efficacy attributable to autophagy‐induced resistance. Notably, triplet therapy was able to potentiate efficacy through elimination of the autophagic flux. Correspondingly, abemaciclib potentiated ribonucleotide reductase catalytic subunit M1 reduction, resulting in sensitization to gemcitabine. Conclusions As such, these data provide robust preclinical mechanistic evidence of synergy between gemcitabine/cisplatin and CDK4/6 inhibitors and delineate a path forward for translation of these findings to preliminary clinical studies in advanced BTC patients.
Histone Deacetylase Sirtuin 1 Promotes Loss of Primary Cilia in Cholangiocarcinoma
Background and Aims Sirtuin 1 (SIRT1) is a complex NAD+‐dependent protein deacetylase known to act as a tumor promoter or suppressor in different cancers. Here, we describe a mechanism of SIRT1‐induced destabilization of primary cilia in cholangiocarcinoma (CCA). Approach and Results A significant overexpression of SIRT1 was detected in human CCA specimens and CCA cells including HuCCT1, KMCH, and WITT1 as compared with normal cholangiocytes (H69 and NHC). Small interfering RNA (siRNA)‐mediated knockdown of SIRT1 in HuCCT1 cells induced cilia formation, whereas overexpression of SIRT1 in normal cholangiocytes suppressed ciliary expression. Activity of SIRT1 was regulated by presence of NAD+ in CCA cells. Inhibition of NAD ‐producing enzyme nicotinamide phosphoribosyl transferase increased ciliary length and frequency in CCA cells and in SIRT1‐overexpressed H69 cells. Furthermore, we also noted that SIRT1 induces the proteasomal mediated degradation of ciliary proteins, including α‐tubulin, ARL13B, and KIF3A. Moreover, overexpression of SIRT1 in H69 and NHC cells significantly induced cell proliferation and, conversely, SIRT1 inhibition in HuCCT1 and KMCH cells using siRNA or sirtinol reduced cell proliferation. In an orthotopic transplantation rat CCA model, the SIRT1 inhibitor sirtinol reduced tumor size and tumorigenic proteins (glioma‐associated oncogene 1, phosphorylated extracellular signal‐regulated kinase, and IL‐6) expression. Conclusions In conclusion, these results reveal the tumorigenic role of SIRT1 through modulation of primary cilia formation and provide the rationale for developing therapeutic approaches for CCA using SIRT1 as a target.
FGFR Inhibitor Toxicity and Efficacy in Cholangiocarcinoma: Multicenter Single-Institution Cohort Experience
PURPOSECholangiocarcinomas (CCA) are a group of heterogeneous tumors arising from the biliary epithelia. Significant sequencing efforts have provided further insights into the molecular mechanisms of this disease including fibroblast growth factor receptor ( FGFR) alterations, which occurs in approximately 15%-20% of intrahepatic CCAs. Herein, we describe the FGFR inhibitor (FGFRi)-associated treatment toxicity and cancer-specific outcomes from a multicenter single-institution cohort.METHODSThis is a retrospective study of patients with CCA and known FGFR alterations treated with FGFRi. We describe the toxicity and efficacy in patients treated at Mayo Clinic between January 2010 and December 2020.RESULTSOur group identified 61 patients with advanced or metastatic CCA, 19 males (31%) and 42 females (69%), harboring FGFR alterations who received FGFRi. The most common grade 1 or higher adverse events for all patients included fatigue (92%), AST elevations (78%), anemia (80%), decreased platelet count (63%), and hyperphosphatemia (74%). Median progression-free survival on FGFRi was 5.8 months for all patients (95% CI, 4.9 to 9.0). Females had significantly longer progression-free survival at 6.9 months (95% CI, 5.2 to 11.8) on FGFRi compared with males at 4.9 months (95% CI, 2.8 to not estimable; P = .038).CONCLUSIONFGFRi are well tolerated with clinical efficacy. With the recent approval of FGFRi by the US Food and Drug Administration and ongoing clinical trials for new FGFRi, understanding outcomes and toxicity associated with these medications is important for precision oncology.
Distinct Patterns of HBV Integration and TERT Alterations between in Tumor and Non-Tumor Tissue in Patients with Hepatocellular Carcinoma
Although hepatitis B virus (HBV) integration into the cellular genome is well known in HCC (hepatocellular carcinoma) patients, its biological role still remains uncertain. This study investigated the patterns of HBV integration and correlated them with TERT (telomerase reverse transcriptase) alterations in paired tumor and non-tumor tissues. Compared to those in non-tumors, tumoral integrations occurred less frequently but with higher read counts and were more preferentially observed in genic regions with significant enrichment of integration into promoters. In HBV-related tumors, TERT promoter was identified as the most frequent site (38.5% (10/26)) of HBV integration. TERT promoter mutation was observed only in tumors (24.2% (8/33)), but not in non-tumors. Only 3.00% (34/1133) of HBV integration sites were shared between tumors and non-tumors. Within the HBV genome, HBV breakpoints were distributed preferentially in the 3’ end of HBx, with more tumoral integrations detected in the preS/S region. The major genes that were recurrently affected by HBV integration included TERT and MLL4 for tumors and FN1 for non-tumors. Functional enrichment analysis of tumoral genes with integrations showed enrichment of cancer-associated genes. The patterns and functions of HBV integration are distinct between tumors and non-tumors. Tumoral integration is often enriched into both human-virus regions with oncogenic regulatory function. The characteristic genomic features of HBV integration together with TERT alteration may dysregulate the affected gene function, thereby contributing to hepatocarcinogenesis.