BACKGROUND:PD-L1 expression and tumor mutational burden (TMB) are biomarkers for immune checkpoint inhibitor (ICI) therapy in non-small cell lung cancer (NSCLC); however, patients harboring oncogenic alterations have limited benefit from ICIs. The impact of oncogenic alterations on TMB and PD-L1 tumor proportion score in lung cytology specimens is poorly understood. Herein, the association between oncogenic alterations, TMB, and PD-L1 in NSCLC cytology specimens is explored. METHODS:Next-generation sequencing results from 312 NSCLC cytology specimens were retrospectively reviewed that interrogate 610 genes and select immuno-oncology signatures. TMB and PD-L1 immunohistochemical expression across oncogenic alterations were analyzed to explore associations. RESULTS:Of the 312 cases evaluated, 192 harbored NSCLC-specific oncogenic alterations. Relative to EGFR-mutated tumors, TMB was significantly higher in KRAS (padj = 2.7 × 10-4), ERBB2 (padj = .023), and BRAF (padj = .023) -mutated tumors but lower in ALK-rearranged tumors (padj = .005). Significantly higher PD-L1 expression was seen in tumors with KRAS (padj = .002) and MET exon 14 (padj = 1.06 × 10-4) when compared to EGFR-mutated tumors. Strong positive correlations between TMB and PD-L1 were observed in ERBB2-, KRAS-, and BRAF-mutated tumors when evaluated as continuous variables. TP53 mutations further enhanced immunogenicity when co-occurring with KRAS, ERBB2, or BRAF mutations but this effect was not observed in EGFR-mutated tumors. CONCLUSIONS:These findings demonstrate distinct TMB and PD-L1 profiles that may identify patients who will benefit from ICI therapy. Cytology specimens provide adequate material for biomarker testing, which underscores their value in guiding immunotherapy decisions.

e16181 Background: Hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) carries a poor prognosis. Immune checkpoint therapy (ICT) enhances antitumor activity through CD8⁺ T-cell proliferation. Direct-acting antivirals (DAAs) have been associated with a remarkable HCV cure rate and have been shown to enhance hepatic and systemic immune responses by reversing the exhaustion of the HCV-specific CD8 + T-cell response. HCV guidelines do not address the optimal timing of DAAs in patients with advanced HCC undergoing ICT. We conducted a phase IV clinical trial in patients with HCV-associated HCC to determine whether clearing HCV with early DAA therapy improves ICT response and enhances the immune response against liver cancer cells by reversing T-cell exhaustion. Methods: In this open-label single-arm clinical trial (NCT05717400), patients with HCV-related HCC received atezolizumab plus bevacizumab and DAAs (sofosbuvir/velpatasvir [SV] or SV/voxilaprevir [SVV]). Peripheral blood samples were collected at baseline and at weeks 4 (W4) and 12 (W12) after DAA initiation for high-dimensional flow cytometry. Tumor biopsies were obtained before and after DAA therapy. Multiplex immunofluorescence quantified intertumoral CD8⁺ T-cell densities and immune-cell phenotypes. Primary endpoints were objective response rate (ORR), disease control rate (DCR), and sustained virological response (SVR). Results: Between March 17, 2023, and August 28, 2024, 11 patients were screened, and 2 were enrolled. Patient 1 was a 74-year-old Black man with metastatic HCC and HCV genotype 2 treated with SV. Patient 2 was a 64-year-old White man with stage IIIB HCC and HCV genotype 1a treated with SVV after initial DAA failure. Both were ICT-naïve, started DAAs within weeks of ICT initiation, experienced no grade 3 or 4 adverse events, had stable disease as their overall best response (DCR 100%; ORR 0%), and had SVR. In both patients, CD4⁺ and CD8⁺ T-cell frequencies increased over time, whereas monocyte frequencies decreased. At all times, both patients had high CD4:CD8 ratios but low natural killer (NK) cell frequencies. We observed no changes in proliferation or in the expression of the activation markers 41BB, OX40, ICOS, or CD69 on T-cell subsets or NK cells. The expression of inhibitory markers in T and NK cell subsets is shown. At W12, patient 1 had increased T-cell densities, while patient 2 had pronounced tumor infiltration by cytotoxic T lymphocytes (CD3⁺CD8⁺) and macrophages (CD68⁺). Conclusions: Early DAA therapy after ICT in patients with advanced HCC was safe and resulted in enhanced CD4⁺ and CD8⁺ T-cell responses with excellent virologic control but did not impact tumor response. Larger clinical trials are warranted to determine whether HCV clearance with DAA therapy enhances ICT response in patients with HCV-related HCC. Clinical trial information: NCT05717400 .

Purpose: Radiation therapy (RT) has emerged as an effective local therapy option for patients with unresectable hepatocellular carcinoma (HCC) and is associated with improved overall survival (OS). However, some patients still have poor outcomes after RT, and biomarkers are needed to stratify prognostic groups. High circulating growth hormone (GH) levels promote HCC proliferation and survival and are associated with aggressive disease. In this study, we evaluated whether pretreatment GH levels are associated with OS and progression-free survival (PFS) in patients who underwent RT for unresectable HCC. Methods and Materials: Patients undergoing RT for HCC during 2017-2023 were identified from a prospectively maintained database. Patients without GH levels measured within 8 weeks of RT were excluded. OS and PFS were compared between patients with high and low GH levels. Results: Thirty-four patients were included. Median age was 67 years, and 73.5% were men. Of the patients, 26.5% had high GH levels. Median follow-up was 10 (IQR, 4-25) months. The median PFS for the GH-low group was 7.9 months versus 3.9 months in the GH-high group (P = .219). The median OS was significantly higher among patients with GH-low levels (15.2 months) than among those with GH-high levels (10.6 months; P = .025). On multivariate analysis, high GH level was significantly associated with increased risk of death (hazard ratio, 3.72; P = .02). Conclusions: In this hypothesis-generating exploratory analysis, high pretreatment GH levels were associated with worse survival outcomes in patients with unresectable HCC undergoing RT. Despite the retrospective design and limited cohort size, these findings provide biologically and clinically relevant preliminary evidence supporting GH as a potential prognostic biomarker. Validation in larger, prospective, multi-institutional cohorts is warranted, and any therapeutic implications related to targeting the GH/GH receptor axis should be considered exploratory.

Abstract Background: HER2 amplification defines a biologically distinct subset of colorectal cancer (CRC), yet its transcriptomic and immune correlates remain incompletely characterized. We profiled HER2-amplified CRCs to delineate clinicogenomic, immune, and transcriptomic features associated with ERBB2-driven oncogenesis. Methods: We used Tempus Lens (Tempus AI, Inc., Chicago, IL) to query the Tempus multimodal de-identified database and identify patients with stage III/IV CRC who underwent Tempus xT (DNA) and xR (RNA) testing with tumor purity ≥30%. HER2 amplification was defined as ERBB2 copy number (CN) ≥6. Demographic and clinical characteristics, somatic and germline alterations, quanTIseq-based immune cell infiltration estimates, and biomarkers (TMB, PD-L1, MSI) were compared. RNA-seq data were normalized to log2(TPM+1), and differential expression and pathway enrichment analyses on the hallmark gene set using fgsea compared HER2-amplified and non-amplified tumors. Results: Among 16,394 patients with diagnoses of colon or rectal adenocarcinoma, 445 (2.7%) were HER2-amplified. These tumors occurred at a younger median age (58 vs. 60 years, p=0.001) and were more often left-sided (70% vs. 57%, p=0.011). Where data were available, ERBB2 amplification showed 88% (36/41) concordance with external HER2 IHC/ISH and a correlation between ERBB2 copy number and mRNA expression (ρ=0.38, p<0.001), demonstrating concordance across DNA, RNA, and protein levels. ERBB2-activating mutations, most frequently V777L (3.15%), followed by G776V, S310F, and H878Y, co-occurred in 9.2% of amplified tumors, suggesting dual genomic and structural activation. HER2-amplified CRCs had fewer KRAS mutations (14% vs. 48%, p<0.001; G12D most common), lower mean TMB (5 vs. 8 mut/Mb, p<0.001), and were universally MSS (MSI-H 0%). Germline mutation frequencies were similar between groups, with CHEK2 and MUTYH most frequent. HER2-amplified tumors demonstrated reduced infiltration of M1 macrophages, NK cells, and Tregs (all p<0.01) and lacked significant enrichment of antigen-presentation, Th1, checkpoint, or co-stimulatory signatures (q=0.06-0.08), indicating a relatively immune-inactive microenvironment compared to non-amplified CRCs. Gene set enrichment analysis revealed a trend toward positive enrichment of cell-cycle and DNA replication programs (E2F, MCM, PLK1, AURKB, TOP2A) and suppression of KRAS signaling in HER2-amplified patients. Conclusions: HER2-amplified CRCs exhibit a coordinated ERBB2 activation axis linking DNA amplification, mRNA overexpression, and protein upregulation. These tumors are characterized by a hyperproliferative yet immune-depleted transcriptional profile. The biological interplay between HER2 signaling, proliferation, and immune modulation warrants further study, and future work should include clinical outcome correlations. Citation Format: Sunyoung Lee, Michelle Weitz, Adam Dugan, Saif Nirzhor, Kayla Layng, Scott Kopetz, James Yu, Asif Rashid, Funda Meric-Bernstam, Mohamed Nuh, Monica Hsiang, Kanwal Pratap Singh Raghav. Molecular and immune landscape of HER2-amplified colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 5286.

BACKGROUND & AIMS:Gallbladder cancer (GBC) is a rare and highly lethal biliary tract cancer with limited treatment options and lack of diagnostic and prognostic noninvasive biomarkers. Circulating cell-free DNA (cfDNA) offers a noninvasive means to capture fragmentomics alterations that may assist with diagnosis and biological characterization. This pilot study aimed to identify cfDNA-based features that differentiate GBC from individuals with gallstones and healthy controls. METHODS:cfDNA was extracted from archived plasma samples from 67 individuals in two case-control studies from China and Chile, followed by low coverage whole genome sequencing to evaluate fragmentomics and related features. cfDNA computational packages were leveraged to generate features and create a classification model. External cfDNA datasets including other hepatopancreatobiliary disease groups were processed and compared to the current study. RESULTS:In this pilot, individuals with GBC displayed significantly altered cfDNA features compared to healthy controls and individuals with gallstones (P<0.05). Key differences were observed in fragment lengths, end motif patterns, estimated tumor fractions, detectable copy number alterations, and transcription factor binding site accessibility, all of which discriminated GBC from a combined non-cancer group (AUC: 0.852). Many of these cfDNA alterations were consistent with the results from paired and unpaired tissue genomics datasets and other related cancer groups (liver cancer, pancreatic cancer, and non-GBC biliary tract cancer). CONCLUSIONS:This proof-of-concept study demonstrates that archived plasma samples can be successfully used for cfDNA sequencing. These methods capture biologically meaningful alterations in GBC that are consistent with tissue-based genomics data. Collectively, these findings highlight the potential of cfDNA profiling for biological characterization and as a promising noninvasive diagnostic tool for GBC. IMPACT AND IMPLICATIONS:This pilot study demonstrates that archived plasma EDTA samples can be used for cfDNA sequencing and reinforces the utility of cfDNA fragmentomics analyses for studying gallbladder disease. By assessing biologically relevant cfDNA features across related hepatopancreatobiliary cancers, we identified common and distinct features that may be used for classification and risk stratification. In high-risk settings for GBC, cfDNA fragmentomics might offer complementary information that could be used to guide clinical decision-making or help optimize waitlists for cholecystectomy.

Purpose:Fibroblast growth factor 21 (FGF21) is a hormone synthesized and released by liver cells. Deficiency in FGF21 has been shown to be associated with steatosis, inflammation, fibrosis, and increased risk of hepatocellular carcinoma (HCC) development. Moreover, recent evidence suggests that elevated FGF21 levels may paradoxically correlate with worse outcomes in HCC. We aimed to evaluate the association between serum FGF21 levels, clinicopathological parameters, and overall survival (OS) in HCC patients. Patients and Methods:From 2001 to 2014, newly diagnosed HCC patients were recruited as part of an IRB-approved protocol. Blood samples were prospectively collected and a CLIA-certified lab measured serum FGF21 concentrations. Using FGF21 median as a cutoff point, all patients were categorized into subjects with low and high levels. The primary endpoint was OS. Results:A total of 767 HCC patients were analyzed. Mean age was 65 years, and 74% were male. Median FGF21 value was 0.41 ng/mL. Our data showed that patients with advanced HCC including those with multinodular tumors, vascular invasion, distant metastasis, a higher Child-Pugh score, CLIP, BCLC, TNM, and ECOG stage had significantly increased FGF21 serum levels (p < 0.05 for all parameters). OS was significantly shorter in patients with high FGF21 compared to those with low FGF21 (24 months OS 28% vs 43%; p < 0.001). On multivariate analysis, high FGF21 was significantly associated with worse OS (HR: 1.422; 95% CI: 1.180-1.714; p < 0.001). Conclusion:Elevated circulating FGF21 levels correlate with advanced clinicopathologic features and poor OS in HCC patients. Because elevated FGF21 during liver stress may indicate significant metabolic disruption, our data provides strong evidence that FGF21 may represent a valuable prognostic and potentially therapeutic biomarker in HCC. Future independent studies are required to validate our results.

Colorectal cancer (CRC) remains a leading cause of cancer-related mortality, with genetic, epigenetic, and immune-dependent mechanisms contributing to disease pathogenesis. Preventive strategies are especially important for individuals with hereditary syndromes such as familial adenomatous polyposis (FAP), in which Adenomatous Polyposis Coli (APC) mutations drive early tumor formation. The polyposis in rat colon (Pirc) model, harboring an Apc mutation, faithfully recapitulates the development of adenomatous polyps, a precursor stage of CRC, in both the colon and duodenum. Here, we report the generation and characterization of primary cell cultures derived from 30 colonic and duodenal adenomas (benign tumors) from Pirc rats. These Pirc colon adenoma and duodenal adenoma cultures demonstrated consistent morphology, epithelial marker expression (E-cadherin and pan-cytokeratin), and robust 3D spheroid formation. Growth kinetics revealed a doubling time of 50 ± 4 hours. Notably, histone deacetylase and bromodomain inhibitors reduced cell viability and colony formation significantly, highlighting the synergistic potential in targeting deregulated epigenetic signatures as early-stage prevention strategies in FAP. These primary cultures, maintained between passages 5 and 10 to preserve phenotypic integrity, offer a valuable ex vivo model for early-stage CRC research and the screening of preventive agents. By bridging genetic susceptibility and translational prevention, this platform provides a novel and reproducible tool for advancing cancer interception.

Introduction KRAS exon 2/3/4 activating mutations characterize ∼40% of colorectal carcinomas (CRCs) and predict resistance to anti-EGFR therapy. Because KRAS mutations’ location conveys distinct biophysical consequences, we investigated whether CRCs’ clinicopathologic features varied by KRAS mutation codon. Methods CRC patients from 2018-2022 were identified from the U.S. National Cancer Database, which reports KRAS as wildtype vs. codon 12/13/61-mutant vs. codon 146-mutant. KRAS codon 146-mutant vs. codon 12/13/61-mutant CRCs were compared using multivariable logistic regression for clinicopathologic features and multivariable Cox regression for overall survival (OS). Results Nationally, n=76,581 CRC patients were identified, 43.3% which were KRAS-mutated (including n=16,366 at codon 12/13/61 and n=784 at codon 146). Among tumor characteristics, codon 146-mutated CRCs were less likely poorly differentiated (12.1%) and more likely moderately differentiated (80.7%) than codon 12/13/61-mutated CRCs (15.9% and 76.0%, respectively; p=0.003). Additionally, codon 146-mutated CRCs less likely involved the sigmoid colon (14.4% vs. 18.1% of codon 12/13/61-mutated CRCs; p=0.004). KRAS codon 146-mutated CRCs were also enriched with MSI-High/MMR-deficiency (10.1% vs. 5.9% of codon 12/13/61-mutated; p<0.001); and less likely concurrently NRAS mutant (1.5% vs. 8.0% of codon 12/13/61-mutated; Chi2 p<0.001). Adjusting for patient characteristics and treatments, no OS difference was observed between KRAS codon 146-mutated and 12/13/61-mutated stage IV CRCs (HR 0.99, 95%CI: 0.86-1.33, p=0.88). Discussion and Conclusion Using U.S. national data, we found that CRCs with KRAS codon 146 mutations differed in their histological grading, primary site location, MSI/MMR status, and concurrent NRAS status – but not OS – as compared to CRCs with KRAS codon 12/13/61 mutations. Together, our findings illustrate that KRAS mutations also have codon-specific manifestations in their clinicopathologic features, which may suggest differences in pathophysiology that warrant further investigation.

Background and objective Ampullary carcinoma (AMPAC) taxonomy is based on morphology and immunohistochemistry. This classification lacks prognostic reliability and unique genetic associations. We applied an approach of integrative genomics characterising patients with AMPAC exploring molecular subtypes that may guide personalised treatments. Design We analysed the mutational landscapes of 170 patients with AMPAC. The discovery included 110 tumour/normal pairs and the validation comprised 60 patients. In a tumour subset, we interrogated the transcriptomes and DNA methylomes. Patients were stratified based on mutational signatures and associated with molecular and clinical features. To evaluate tumour and immune cellularity, 22 tumours were independently assessed histomorphologically and by digital pathology. Results We defined three patient clusters by mutational signatures independent of histomorphology. Cluster 1 (C1) was defined by spontaneous deamination of DNA 5-methylcytosine and defective mismatch repair. C2 and C3 were related to the activity of transcription-coupled nucleotide excision repair but C3 was further defined by the polymerase eta mutational process. C1-2 showed enrichment of Wnt pathway alterations, aberrant DNA methylation profiles, immune cell exclusion and patients with poor prognosis. These features were associated with a hypermutator phenotype caused by C>T alterations at CpGs. C3 patients with improved overall survival were associated with activation of immune-related pathways, immune infiltration and elevated expression of immunoinhibitory checkpoint genes. Conclusion Immunogenicity and Wnt pathway associations, emphasised by the mutational signatures, defined patients with prospective sensitivity to either immunotherapy or Wnt pathway inhibitors. This emphasises a novel mutational signature-based AMPAC classification with prognostic potential, suggesting prospective implications for subgroup-specific management of patients with AMPAC.

Hepatocellular carcinoma (HCC) mortality is increasing globally, partly due to the growing prevalence of nonviral liver diseases. Genome-wide association studies (GWAS) have identified genetic variants associated with HCC development. Leveraging GWAS summary statistics and linkage disequilibrium score regression (LDSR), we investigated disease co-development with hepatitis C virus-negative (HCV-negative) HCC to provide unique insights into HCC etiology and prioritize relationships for further causal inquiry. We utilized the LDSR statistical framework to estimate the genetic correlation and heritability between HCV-negative HCC with 901 epidemiologic, behavioral, and clinical traits from the United Kingdom Biobank (UKBB). First, we set the threshold for observed scale heritability of each trait at 0.02 to ensure reliable inferences with adequate study power. Next, we observed significant positive genetic correlations between HCV-negative HCC and blood-based biomarkers of liver injury (ALT, GGT) and allostatic load (including glycated hemoglobin, blood pressure, and total albumin). We also identified a positive genetic correlation between HCV-negative HCC and diseases associated with metabolic dysfunction-associated steatotic liver disease (MASLD), including diabetes, hypertension, chronic ischemic heart disease, and others. Taken together, our results help to identify polygenic and pleiotropic signals related to different phenotypic traits associated with HCC and support further exploration of the predictive power of blood-based biomarkers identified in this study for inferring HCC development among HCV-negative individuals.

A fusion between tubulin polymerization-promoting protein (TPPP), a regulatory cytoskeletal gene, and the chromatin remodeling factor, bromodomain-containing protein 9 (BRD9), TPPP-BRD9 fusion has been found in rare cancer cases, including lung and gallbladder cancers (GBC). In this study, we investigated the histopathological features of 16 GBCs previously shown by RNA sequencing to harbor the TPPP-BRD9 fusion. Findings in the fusion-positive GBCs were compared with 645 GBC cases from the authors' database. Among the 16 TPPP-BRD9 fusion-positive GBC cases, most were females (F:M = 7:1) of Chinese ethnicity (12/16), whereas the remaining cases were from Chile. The histopathological examination showed the following findings: 1) Intracholecystic neoplasm (ICN) in 7/15 (47% vs. 7% 645 reference GBCs, p < 0.001), all with gastro-pancreatobiliary phenotype, often with clear cell change, and in the background of pyloric gland metaplasia and extensive high-grade dysplasia. 2) Neuroendocrine carcinoma (NEC) morphology: 3 cases (27% vs. 4.6% in the reference database, p = 0.001) showed a sheet-like and nested/trabecular growth pattern of monotonous cells with salt-and-pepper chromatin characteristic of NECs. Two were large cell type, one had prominent clear cell features, a rare finding in GBNECs; the other one had relatively bland, well-differentiated morphology, and the remaining case was small cell type. 3) Adenocarcinoma identified in 8 cases had a distinctive pattern characterized by widely separated small, round tubular units with relatively uniform nuclei in a fashion seen in mesonephric adenocarcinomas, including hobnail-like arrangement and apical snouts, reminiscent of tubular carcinomas of the breast in many areas. In some foci, the epithelium was attenuated, and glands were elongated, some with comma shapes, which along with the mucinous/necrotic intraluminal debris created a "syringoid" appearance. 4) Other occasional patterns included the cribriform, glomeruloid patterns, and metaplastic tubular-spindle cell pattern accompanied by hemorrhage. In conclusion, TPPP-BRD9 fusion-positive GBCs often develop through intracholecystic neoplasms (adenoma-carcinoma sequence) of gastro-pancreatobiliary lineage, appear more prone to form NEC morphology and have a propensity to display clear cell change. Invasive adenocarcinomas arising in this setting often seem to display a distinctive appearance that we tentatively propose as the TPPP-BRD9 fusion-positive pattern of GBC.

Introduction: Perioperative immunotherapy has shown promise in some patients with early-stage hepatocellular carcinoma (HCC). This study examined tissue and imaging biomarkers associated with pathologic response in a phase II clinical trial in patients with resectable HCC. Methods: Analysis included 18 patients with biopsy-proven resectable HCC treated with neoadjuvant nivolumab plus ipilimumab or nivolumab alone in a phase II clinical trial at MD Anderson Cancer Center (NCT03222076). Liver MRE (to measure tissue fibrosis) and biopsies (to evaluate immune activation markers) were obtained serially pretreatment and after completing neoadjuvant immunotherapy. A major pathologic response (MPR) was defined as tumor necrosis of more than 70%. Data comparing patients with MPR versus those without were summarized using descriptive statistics and compared using the Wilcoxon rank-sum test. Results: Patients with MPR after neoadjuvant immunotherapy tended to have larger tumors (mean 9.52 vs. 4.99 centimeters; p = 0.050). They had a significant reduction in tumor size posttreatment (14.67% reduction vs. 9.15% increase in size; p = 0.042) and a nonsignificant decrease in serum AFP (-24.20% vs. -14.00%; p = 0.085). Further, patients with MPR had a greater increase in intratumoral expression levels of CD8 (26.92% vs. -0.04%; p = 0.026), granzyme B (15.56% vs. -2.24%; p = 0.011), and PD-1 (20.17% vs. 0.40%; p = 0.048) but not PD-L1 (7.69% vs. 0.57%; p = 0.26). For imaging biomarkers, tumor and liver fibrosis were comparable before and after neoadjuvant therapy in patients with MPR versus nonresponders. Conclusion: Changes in tumor size, immune cell infiltration, and immune cell activation are candidate predictive markers of pathologic response to neoadjuvant immunotherapy in patients with resectable HCC.

BACKGROUND: Circulating tumor DNA (ctDNA) is a promising non-invasive marker for detection, diagnosis, treatment selection, and prognosis of hepatocellular carcinoma (HCC). OBJECTIVE: This study aimed to examine the utility of ctDNA as a prognostic and predictive tool in HCC patients treated with nivolumab. METHODS: We analyzed pre-treatment ctDNA from 44 HCC patients using comprehensive genomic testing on a commercially available platform. We utilized log rank test and univariate Cox models to correlate overall survival (OS) and progression-free survival (PFS) with ctDNA expressions. RESULTS: Of 44 patients, 77.3% were men with median age of 67 years. All but 3 patients had at least one alteration identified, and TP53 was the most commonly altered gene (52.3%). Median OS was 17.5 months (95% CI: 12.7, NA). Mutations involving PIK3CA, BRCA1, and CCND1 amplification were associated with shorter OS (P 0.0001, 0.0001 and 0.01, respectively). Median PFS time was 4.01 months (95% CI: 3.06, 9.33). Mutations involving KIT and PIK3CA were associated with shorter PFS (P 0.0001 and 0.0004, respectively), while mutation involving CTNNB1 were associated with longer PFS (p= 0.04). CONCLUSIONS: ctDNA profiling may provide a benefit for prediction of survival and progression of HCC patients treated with nivolumab. Future studies are needed for confirmation.