mRECIST for HCC: Performance and novel refinements

Summary In 2010, modified RECIST (mRECIST) criteria were proposed as a way of adapting the RECIST criteria to the particularities of hepatocellular carcinoma (HCC). We intended to overcome some limitations of RECIST in measuring tumour shrinkage with local and systemic therapies, and also to refine the assessment of progression that could be misinterpreted with conventional RECIST 1.1, due to clinical events related to the natural progression of chronic liver disease (development of ascites, enlargement of lymph nodes, etc.). mRECIST has served its purpose since being adopted or included in clinical practice guidelines (European, American and Asian) for the management of HCC; it has also been instrumental for assessing response and time-to-event endpoints in several phase II and III investigations. Nowadays, mRECIST has become the standard tool for measurement of radiological endpoints at early/intermediate stages of HCC. At advanced stages, guidelines recommend both methods. mRECIST has been proven to capture higher objective response rates in tumours treated with molecular therapies and those responses have shown to be independently associated with better survival. With the advent of novel treatment approaches (i.e. immunotherapy) and combination therapies there is a need to further refine and clarify some concepts around the performance of mRECIST. Similarly, changes in the landscape of standard of care at advanced stages of the disease are pointing towards progression-free survival as a potential primary endpoint in some phase III investigations, as effective therapies applied beyond progression might mask overall survival results. Strict recommendations for adopting this endpoint have been reported. Overall, we review the performance of mRECIST during the last decade, incorporating novel clarifications and refinements in light of emerging challenges in the study and management of HCC

Reply to: ''Network-based discovery of gene signature for vascular invasion prediction in HCC''

To the Editor:Liu and colleagues raise some issues regarding our recently pub-lished study [1] to which we would like to make the followingcomments. We acknowledge the limitations that a gene-expres-sion-based biomarker could have, and that our signature is notunique. Certainly, previous attempts to find such a signature havebeen published in the past [2]. We also know that, as in othergene expression studies, potential bias could occur. In fact,reported prognostic signatures are often not reproducible, inmost of the cases due to suboptimal study design, small samplesizes, and also because many of them have been based on retro-spectively collected tissue samples [3]. Even after taking intoaccount these sources of bias or inconsistencies, it so happensthat only a small minority of the reported signatures truly retainprognostic significance. In fact, our recent outcome analysisincluding 22 gene signatures with prognostic significance inHCC (18 from the tumor, and four from the non-tumoral adjacenttissue) showed that only two signatures retained independentprognostic value [4].In our work, we select a training cohort based upon a homo-geneous etiology to minimize the risk of molecular heterogene-ity and to identify a clean and distinct signature. Patients withHCV-related HCC were selected, since this is the most commonetiology in the Western countries. Then, we validate the signa-ture in an independent multi-etiologic cohort of patients andthe accuracy remained stable when an etiology-dependent sub-group analysis was performed [1]. The study was aimed at pro-viding a gene-set to ease the preoperative diagnosis of vascularinvasion, but was not designed for defining outcome prediction.Nonetheless, we have data indicating that the presence of a vas-cular invasion signature correlates with poor outcome, since thesignature was found to be associated with early recurrence(p = 0.057), and was enriched in patients sharing signatures ofpoor prognosis [4].Even considering that the question posed is simple (to identifya gene-signature capturing vascular invasion) the characteristicsof patients, sample collection, sampling issues, technical varia-tion, validation of results, and bioinformatics approaches are cer-tainly heterogeneous, and thus the results might vary. In mostinstances, however, the different signatures seem to be able tocapture common oncogenic mechanisms, as reflected by theircapacity to adequately allocate patients into a poor or good prog-nosis group [5]. By applying a different methodological approach(weighted gene co-expression network analysis) to our data, Liuet al. provide a 9-gene signature with similar accuracy and nooverlap with our 35-gene signature. The method applied is basedon systems biology to find clusters of highly correlated genesacross microarray samples, identify hubs of each module and cor-relate them with clinical traits [6]. This analysis is based on thehypothesis that information on signaling pathways is crucial tounderstand how genes are connected to each other and how theyinfluence cellular functions in both normal and cancer conditions.This result further underlines the need for integrating the vastamount of available data and the development of powerful bioin-formatics resources (annotation, methodologies, technical plat-forms, etc.).A more relevant question is when can our signature-alone orin combination with tumor size- be translated into clinical prac-tice. Strict rules have been proposed recently by Simon and col-leagues [7]. Following this proposal, the EASL-EORTC guidelineson management of HCC have outlined a list of requirements inorder to adopt molecular signatures in the clinical practice [8],which are as follows:1. First, the signature should be generated in the setting of ran-domized studies or in case of cohort studies, it should followthe training/validation approach.2. The signature should retain independent prognostic valuewhen tested along known clinico-pathological variables.3. The results should be confirmed by independent investigatorsin a separate set of samples.Thus, according to these rules, in order to implement our sig-nature in the decision-making process, for instance in the waitinglist of liver transplantation, it should be validated by independentinvestigators in a novel set of samples. Ideally, the signature hasto be reproduced in a device, which should give similar results.Only then, data is ready for acceptance in guidelines. It is a longpath, but the only one for translation of genomic results into ourpractice.Conflict of interestThe authors declared that they do not have anything to discloseregarding funding or conflict of interest with respect to thismanuscript.Reference

Obesity, Inflammatory Signaling, and Hepatocellular Carcinoma—An Enlarging Link

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Translating '–omics' results into precision medicine for hepatocellular carcinoma

A large-scale comprehensive analysis of hepatocellular carcinoma (HCC) based on the integration of six distinct data platforms has pinpointed novel oncogenic processes and prognostic subgroups. These findings confirm previously identified molecular subclasses and fuel the need for a clear strategy of precision medicine in HCC

Cancer gene discovery in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a deadly cancer, whose incidence is increasing worldwide. Albeit the main risk factors for HCC development have been clearly identified, such as hepatitis B and C virus infection and alcohol abuse, there is still preliminary understanding of the key drivers of this malignancy. Recent data suggest that genomic analysis of cirrhotic tissue - the pre-neoplastic carcinogenic field - may provide a read-out to identify at risk populations for cancer development. Given this contextual complexity, it is of utmost importance to characterize the molecular pathogenesis of this disease, and pinpoint the dominant pathways/drivers by integrative oncogenomic approaches and/or sophisticated experimental models. Identification of the dominant proliferative signals and key aberrations will allow for a more personalized therapy

Impact of fertilization with pig slurry on the isotopic composition of nitrate retained in soil and leached to groundwater in agricultural areas

The isotopic composition of N and O of nitrate (NO3−) is usually employed to trace its sources of pollution in groundwater. In agricultural areas, the amount of NO3− that reaches the aquifers after fertilization is controlled by different transformation processes that can affect the nitrogen species isotopic composition. Aiming to address the reliability of using isotope tools to trace sources of groundwater NO3−, the goal of this study was to check the effect of fertilization on the isotopic composition of N compounds retained and leached from soils. The concentration and isotopic composition (δ15N and δ18O) of ammonium (NH4+), NO3− and nitrite (NO2−) was characterized after the application of pig slurry in lysimeters containing either soil under fallow (LF) or the same soil continuously cropped and fertilized (LC) during the previous six years. Results showed that the leached NO3− isotopic signature did not directly reflect the isotopic composition of the applied pig slurry. Just after fertilization, nitrification led to lower δ15NNO3 values in soil extracts and leachates (e.g. from +5.9 ± 0.9¿ to +3.8 ± 3.1¿ in soil extracts of LF lysimeters). These values increased after complete nitrification (+11.5 ± 1.3¿) towards the δ15Nbulk of pig slurry (+19.6 ± 0.5¿). Later on, due to soil organic matter and plant debris mineralization and subsequent nitrification, values decreased towards the initial δ15NNO3 of soil but remained above them (+8.6 ± 1.0¿). Both LF and LC experiments showed a similar trend and the latter ones allowed to reinforce that long-term fertilization with pig slurry can increase the soil δ15NNO3. Concerning the δ18O of NO3− from soil extracts and leachates, it mainly depended on the δ18O of irrigation water and oxygen, after nitrification of NH4+ from pig slurry. Therefore, studies aiming to trace groundwater NO3− pollution sources in rural areas by using an isotopic approach should consider the fertilization history of each setting. Also, analyzing the δ15Nbulk of soil is recommended, since it could mask the isotopic signature of the N applied through fertilization

Beta-catenin cleavage enhances transcriptional activation

Nuclear activation of Wnt/β-catenin signaling is required for cell proliferation in inflammation and cancer. Studies from our group indicate that β-catenin activation in colitis and colorectal cancer (CRC) correlates with increased nuclear levels of β-catenin phosphorylated at serine 552 (pβ-Cat552). Biochemical analysis of nuclear extracts from cancer biopsies revealed the existence of low molecular weight (LMW) pβ-Cat552, increased to the exclusion of full size (FS) forms of β-catenin. LMW β-catenin lacks both termini, leaving residues in the armadillo repeat intact. Further experiments showed that TCF4 predominantly binds LMW pβ-Cat552 in the nucleus of inflamed and cancerous cells. Nuclear chromatin bound localization of LMW pβ-Cat552 was blocked in cells by inhibition of proteasomal chymotrypsin-like activity but not by other protease inhibitors. K48 polyubiquitinated FS and LMW β-catenin were increased by treatment with bortezomib. Overexpressed in vitro double truncated β-catenin increased transcriptional activity, cell proliferation and growth of tumor xenografts compared to FS β-catenin. Serine 552-> alanin substitution abrogated K48 polyubiquitination, β-catenin nuclear translocation and tumor xenograft growth. These data suggest that a novel proteasome-dependent posttranslational modification of β-catenin enhances transcriptional activation. Discovery of this pathway may be helpful in the development of diagnostic and therapeutic tools in colitis and cancer