Trunk mutational events present minimal intra- and inter-tumoral heterogeneity in hepatocellular carcinoma.

BACKGROUND & AIMS: According to the clonal model of tumor evolution, trunk alterations arise at early stages and are ubiquitous. Through the characterization of early stages of hepatocarcinogenesis, we aimed to identify trunk alterations in hepatocellular carcinoma (HCC) and study their intra- and inter-tumor distribution in advanced lesions. METHODS: A total of 151 samples representing the multistep process of hepatocarcinogenesis were analyzed by targeted-sequencing and a single nucleotide polymorphism array. Genes altered in early lesions (31 dysplastic nodules [DNs] and 38 small HCCs [sHCC]) were defined as trunk. Their distribution was explored in: a) different regions of large tumors (43 regions, 21 tumors), and b) different nodules of the same patient (39 tumors, 17 patients). Multinodular lesions were classified as intrahepatic metastases (IMs) or synchronous tumors based on chromosomal aberrations. RESULTS: TERT promoter mutations (10.5%) and broad copy-number aberrations in chromosomes 1 and 8 (3-7%) were identified as trunk gatekeepers in DNs and were maintained in sHCCs. Trunk drivers identified in sHCCs included TP53 (23%) and CTNNB1 (11%) mutations, and focal amplifications or deletions in known drivers (6%). Overall, TERT, TP53 and CTNNB1 mutations were the most frequent trunk events and at least one was present in 51% of sHCCs. Around 90% of mutations in these genes were ubiquitous among different regions of large tumors. In multinodular HCCs, 35% of patients harbored IMs; 85% of mutations in TERT, TP53 and/or CTNNB1 were retained in primary and metastatic tumors. CONCLUSIONS: Trunk events in early stages (TERT, TP53, CTNNB1 mutations) were ubiquitous across different regions of the same tumor and between primary and metastatic nodules in >85% of cases. This concept supports the knowledge that single biopsies would suffice to capture trunk mutations in HCC. LAY SUMMARY: Trunk alterations arise at early stages of cancer and are shared among all malignant cells of the tumor. In order to identify trunk alterations in HCC, we characterized early stages of hepatocarcinogenesis represented by dysplastic nodules and small lesions. Mutations in TERT, TP53 and CTNNB1 genes were the most frequent. Analyses in more advanced lesions showed that mutations in these same genes were shared between different regions of the same tumor and between primary and metastatic tumors, suggesting their trunk role in this disease.

Progenitor cell markers predict outcome of patients with hepatocellular carcinoma beyond Milan criteria undergoing liver transplantation.

BACKGROUND & AIMS: In patients with hepatocellular carcinoma (HCC), liver transplantation (LT) is an excellent therapy if tumor characteristics are within the Milan criteria. We aimed to define genomic features enabling to identify HCC patients beyond Milan criteria who have acceptable transplant outcomes. METHODS: Among 770 consecutive HCC patients transplanted between 1990 and 2013, 132 had tumors exceeding Milan criteria on pathology and were enrolled in the study; 44% of the patients satisfied the 'up-to-7 rule' [7=sum of the size of the largest tumor and the number of tumors]. Explant tumors were assessed for genomic signatures and immunohistochemical markers associated with poor outcome. RESULTS: At a median follow-up of 88months, 64 patients had died and 45 recurred; the 5-year overall survival (OS) and recurrence rates were 57% and 35%, respectively. Cytokeratin 19 (CK19) gene signature was independently associated with recurrence [Hazard ratio (HR)=2.95, p<0.001], along with tumor size (HR=3.37, p=0.023) and presence of satellites (HR=2.98, p=0.001). S2 subclass signature was independently associated with poor OS (HR=3.18, p=0.001), along with tumor size (HR=5.06, p<0.001) and up-to-7 rule (HR=2.50, p=0.002). Using the presence of progenitor cell markers (either CK19 or S2 signatures) patients were classified into poor prognosis (n=58; 5-year recurrence 53%, survival 45%) and good prognosis (n=74; 5-year recurrence 19%, survival 67%) (HR=3.16, p<0.001 for recurrence, and HR=1.72, p=0.04 for OS). CONCLUSIONS: HCC patients transplanted beyond Milan criteria without gene signatures of progenitor markers (CK19 and S2) achieved survival rates similar as those within Milan criteria. Once prospectively validated, these markers may support a limited expansion of LT indications.

Serum markers for predicting abdominal surgery outcomes in patients with cirrhosis.

BACKGROUND: Determinants of adverse events for cirrhotic patients undergoing abdominal surgery have not been adequately assessed. Child-Turcotte-Pugh (CTP) and Model for End-Stage Liver Disease (MELD) have estimated perioperative outcomes with inconsistent results. Our study sought to combine novel serum markers with CTP and MELD to improve prognostication of 30-day postoperative mortality or liver transplant in cirrhotic patients undergoing abdominal surgery. METHODS: A review was performed on 120 cirrhotic patients undergoing nonhepatic abdominal surgeries at Mount Sinai Medical Center from 2001-2011. Preoperative serum markers were evaluated by logistic regression and receiver-operator characteristics. Prognostic ability of scoring systems was assessed using Youden's J statistic (J). RESULTS: Albumin and hematocrit were independently predictive of 30-day mortality or transplant with optimal cutoff values of albumin at <3.05 mg/dl and hematocrit at <35.55 %. Adding these criteria to CTP>A, CTP>B, MELD ≥ 10, MELD ≥ 15, and MELD ≥ 20 improved sensitivity and specificity by an average of 6.1 and 32.1 %, respectively. The highest J values resulted from combining novel criteria with CTP>A (sensitivity, 80 %; specificity, 82 %; p < 0.01; J, 0.63) and MELD ≥ 10 (sensitivity, 63 %; specificity, 90 %; p < 0.01; J, 0.53). CONCLUSION: Augmenting CTP and MELD with albumin and hematocrit significantly improved the identification of cirrhotic patients at risk of 30-day mortality or transplantation following nonhepatic abdominal surgery.