Clinical significance of alpha-fetoprotein mRNA in blood of patients with hepatocellular carcinoma

Is liquid biopsy the future commutator of decision-making in liver transplantation for hepatocellular carcinoma?

Liver transplant (LT) is the most favorable treatment option for patients with early stage hepatocellular carcinoma (HCC). Numerous attempts have been pursued to establish eligibility criteria and select HCC patients for LT, leading to various systems that essentially integrate clinico-morphological variables. Lacking of sufficient granularity to recapitulate the biological complexity of the disease, all these alternatives display substantial limitations and are thus undeniably imperfect. Liquid biopsy, defined as the molecular analysis of circulating analytes released by a cancer into the bloodstream, was revealed as an incomparable tool in the management of cancers, including HCC. It appears as an ideal candidate to refine selection criteria of LT in HCC. The present comprehensive review analyzed the available literature on this topic. Data in the field, however, remain scarce with only 17 studies. Although rare, these studies provided important and encouraging findings highlighting notable prognostic values and supporting the contribution of liquid biopsy in this specific clinical scenario. These results underpinned the critical and urgent need to intensify and accelerate research on liquid biopsy, in order to determine whether and how liquid biopsy may be integrated in the decision-making of LT in HCC.

Clinical value of circulating tumor cells for the diagnosis and prognosis of hepatocellular carcinoma (HCC): A systematic review and meta-analysis

BACKGROUND

To evaluate the clinical value of circulating tumor cell (CTC) detection in peripheral blood for the diagnosis and prognosis of hepatocellular carcinoma (HCC).

METHODS

Public databases were searched, and a meta-analysis was performed to determine the specificity, sensitivity, negative- likelihood ratio (NLR) and positive-likelihood ratio (PLR), and diagnostic odds ratio (dOR) of CTC detection for the diagnosis of HCC. Hazard ratios (HRs) and 95% confidence intervals (CIs) were analyzed for the association of CTC detection with overall survival (OS) and HCC recurrence. The Meta-DiSc 1.4 and Review Manager 5.2 software programs were used for statistical analysis.

RESULTS

Meta-analysis of 20 studies including 1191 patients showed that the specificity, sensitivity, NLR, PLR, and dOR of CTC testing for HCC diagnosis were 0.60 (95% CI = 0.57-0.63), 0.95 (95%CI = 0.93-0.96), 0.36 (95%CI = 0.28-0.48), 11.64 (95%CI = 5.85-23.14), and 38.94 (95%CI = 18.33-82.75), respectively. Meta-analysis of 18 studies including 1466 patients indicated that the OS of CTC-positive HCC patients was less than that of CTC-negative patients (HR = 2.31; 95% CI = 1.55-3.42; P < .01). Meta-analysis of 5 studies including 339 patients revealed that the presence of CTCs in peripheral blood significantly increased the risk of HCC recurrence (HR = 3.03, 95% CI = 1.89-4.86; P < .01).

CONCLUSION

CTCs in peripheral blood may be a useful marker for HCC diagnosis. In addition, the prognosis of CTC-positive HCC patients was significantly worse than that of CTC-negative HCC patients. Therefore, further studies are warranted to confirm the clinical potential of CTC detection in peripheral blood in patients with primary HCC.

The use of cell free DNA in the diagnosis of HCC

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide and is associated with high mortality. The currently used methods for diagnosing HCC, including imaging modalities and liver biopsy, detect tumors at a relatively advanced stage or are invasive. Non-invasive biomarkers are urgently needed to facilitate screening and early diagnosis of HCC, as well as treatment monitoring and detection of tumor recurrence. Liquid biopsy, the analysis of blood or other body fluids to obtain genetic and epigenetic information, has historically been applied to other types of cancer including breast and prostate cancer. Over the past few decades, liquid biopsy analysis has shed significant insights on genetic and epigenetic aberrations in HCC detectable in peripheral blood. Aberrations in nucleic acids found circulating freely in body fluids or contained within extracellular vesicles such as exosomes or microvesicles show potential clinical utility as non-invasive biomarkers. In this review, we present available literature on cell-free nucleic acids in the diagnosis of HCC.

Role of Allelic Imbalance in Predicting Hepatocellular Carcinoma (HCC) Recurrence Risk After Liver Transplant

Background

One of the most controversial problems for liver transplantation in patients affected by hepatocellular carcinoma (HCC) remains the lack of an oncologic staging system to predict cancer recurrence after liver transplantation (LT). We analyzed allelic imbalance (AI) in 19 microsatellites, and assessed the post-LT HCC recurrence risk.

Material/Methods

Seventy-one patients were included; 18 had tumor recurrence within 5 years post-transplant. Molecular analysis was done in the primary HCC and peripheral blood samples: a total of 19 microsatellites was used to assess AI. Specific AI was evaluated when outside of range value between 0.66 and 1.5. Based on data in the literature, we grouped the 19 microsatellites into 4 panels. We calculated the fractional allelic imbalance (FAI) to make comparisons between different panels including different subsets of microsatellites.

Results

We report that AI was associated with HCC recurrence in 3 main loci (D3S2303, D9S251, and D9S254). Tumor recurrence was associated only with 2 specific panels with 9 microsatellites previously reported to be associated with high risk for HCC recurrence. Our data show that fractional allelic imbalance (FAI) index has good negative ability to predict HCC recurrence (Panel 2: negative predictive value of 95%).

Conclusions

AI analysis could have prognostic value in risk management of HCC recurrence after LT, especially for early recurrence.

Clinical applications of liquid biopsy as prognostic and predictive biomarkers in hepatocellular carcinoma: circulating tumor cells and circulating tumor DNA

Hepatocellular carcinoma (HCC) is a highly malignant disease with a poor prognosis and high mortality due to a low early diagnosis rate, resistance to systemic treatments and progression to late-stage liver disease. Owing to limitations in the detection of HCC and the lack of awareness of healthcare systems, fewer than 40% of HCC patients are eligible for surgery due to advanced stages of the disease at the time of diagnosis and the occurrence of multiple lesions in the cirrhotic or fibrotic liver. At present, the updated American Association for the Study of Liver Disease (AASLD) guidelines no longer recommend alpha-fetoprotein (AFP) testing as a part of diagnostic evaluation. Thus, it is imperative to establish a novel diagnostic strategy with high sensitivity and reliability to monitor risk factors to detect HCC at an early stage. In recent years, “liquid biopsy,” (including circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA)), has emerged as a technique for the characterization of circulating cells, providing a strong basis for the individualized treatment of patients. As a noninvasive detection method, liquid biopsy is expected to play an important role in the early diagnosis, dynamic monitoring of cancer patients and drug screening. In this review, we will focus on the clinical applications, recent studies and future prospects of liquid biopsy, particularly focusing on HCC.

Liquid biopsy in patients with hepatocellular carcinoma: Circulating tumor cells and cell-free nucleic acids

Hepatocellular carcinoma (HCC), with its high incidence and mortality rate, is one of the most common malignant tumors. Despite recent development of a diagnostic and treatment method, the prognosis of HCC remains poor. Therefore, to provide optimal treatment for each patient with HCC, more precise and effective biomarkers are urgently needed which could facilitate a more detailed individualized decision-making during HCC treatment, including the following; risk assessment, early cancer detection, prediction of treatment or prognostic outcome. In the blood of cancer patients, accumulating evidence about circulating tumor cells and cell-free nucleic acids has suggested their potent clinical utilities as novel biomarker. This concept, so-called "liquid biopsy" is widely known as an alternative approach to cancer tissue biopsy. This method might facilitate a more sensitive diagnosis and better decision-making by obtaining genetic and epigenetic aberrations that are closely associated with cancer initiation and progression. In this article, we review recent developments based on the available literature on both circulating tumor cells and cell-free nucleic acids in cancer patients, especially focusing on Hepatocellular carcinoma.

A score model for predicting post-liver transplantation survival in HBV cirrhosis-related hepatocellular carcinoma recipients: a single center 5-year experience

BACKGROUND

The prognostic prediction of liver transplantation (LT) guides the donor organ allocation. However, there is currently no satisfactory model to predict the recipients' outcome, especially for the patients with HBV cirrhosis-related hepatocellular carcinoma (HCC). The present study was to develop a quantitative assessment model for predicting the post-LT survival in HBV-related HCC patients.

METHODS

Two hundred and thirty-eight LT recipients at the Liver Transplant Center, First Affiliated Hospital, Zhejiang University School of Medicine between 2008 and 2013 were included in this study. Their post-LT prognosis was recorded and multiple risk factors were analyzed using univariate and multivariate analyses in Cox regression.

RESULTS

The score model was as follows: 0.114X(Child-Pugh score)-0.002X(positive HBV DNA detection time)+0.647X(number of tumor nodules)+0.055X(max diameter of tumor nodules)+0.231XlnAFP+0.437X(tumor differentiation grade). The receiver operating characteristic curve analysis showed that the area under the curve of the scoring model for predicting the post-LT survival was 0.887. The cut-off value was 1.27, which was associated with a sensitivity of 72.5% and a specificity of 90.7%, respectively.

CONCLUSION

The quantitative score model for predicting post-LT survival proved to be sensitive and specific.

Optimal tailored screening protocol after living donor liver transplantation for hepatocellular carcinoma

The indication for hepatocellular carcinoma (HCC) is expanding in living donor liver transplantation (LDLT). Early detection and effective management of recurrence has become an important issue in LDLT for HCC. This study aimed to find an optimal screening protocol in terms of screening interval and screening tools by analyzing recurrence pattern after LDLT for HCC. A total of 205 LDLT patients in two centers from February 1999 to October 2010 was reviewed. Recurrence appeared in 55 cases. Six risk factors for recurrence were identified: preoperative alpha-fetoprotein >400, Edmonson grade 3 or 4, tumor size >7 cm, tumor number ≥7, minimal tumor necrosis in the transarterial chemoembolization group and positive micro-vascular invasion. Four groups with different ranges of index scores showed different recurrence-free survival and median time to recurrence. Group I showed low and late recurrence. Groups II and III showed linearly increased rate of recurrence until 18 months. Group IV showed very early recurrence within 6 months. Across the groups, extra-hepatic recurrence developed in more than 40% of cases and multi-organ recurrence rate was 20%. The screening interval should be different based on the risk of recurrence. Screening should include work-up for extra-hepatic recurrence as well as intra-hepatic recurrence.

Detection of circulating tumour cells in gastric and hepatocellular carcinoma: a systematic review

OBJECTIVE

This systematic review was conducted to summarize the use of circulating tumour cell (CTC) detection as a prognostic indicator in gastric cancer and hepatocellular carcinoma (HCC).

METHODS

Databases (MEDLINE®, EMBASE®, SCOPUS, Web of Science, Conference Proceedings Citation Index-Science, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov) were searched to identify studies that reported the detection of CTCs in patients with gastric cancer or HCC.

RESULTS

Fifteen studies in patients with gastric cancer and 10 studies in patients with HCC, with a total of 793 and 577 patients, respectively, met the specific inclusion criteria for further analysis. Heterogeneity and potential bias among the studies prevented any statistical analysis.

CONCLUSION

Several methodological techniques have allowed the detection of CTCs in patients with gastric cancer or HCC, but the studies identified in this report generally reported on small cohorts and there was heterogeneity and potential bias in the studies. This highlights the need for large systematic multicentre clinical trials to confirm the potential prognostic benefit of detecting CTCs in patients with cancer.

[Disseminated and circulating tumor cells in gastrointestinal oncology]

Circulating (CTC) and disseminated tumor cells (DTC) represent two different steps of the metastatic process. As with other types of cancer, the recent development of techniques for the detection of CTC and DTC respectively in the blood and bone marrow of patients generated many results in digestive cancers. However, the interpretation of these results and of the prognostic value of CTC/DTC is often limited by the small cohort size and the heterogeneity of detection methods. The aim of this article is to review the different results and their clinical impact, and discuss the possible use of CTC and DTC as new biomarkers. First of all, it is important to take into account the variability of epithelial markers used for the initial stage of immunoselection of CTC/DTC as well as that of molecular or cytological markers used for the second stage of detection. In esophageal, gastric, pancreatic and hepatocellular carcinomas, and in the ileal and pancreatic neuroendocrine tumors, some studies showed a correlation between the detection of CTC and/or DTC and a clinical pejorative course, whether these tumors were at localized or metastatic stages. On colorectal cancer in the adjuvant setting, a recent meta-analysis showed an association between the detection of CTC in peripheral blood and disease-free survival or overall survival. These results are consistent with those of a study that identified detection of CTC as a prognostic factor for relapse in stage II. This last study concluded that it was necessary to achieve long-term evaluation of CTC as a biomarker to guide the decisions of chemotherapy for stage II. In metastatic colorectal cancer, the FDA approved in 2007 the use of pretherapeutic levels of CTC and its variations per-treatment, determined by CellSearch(®) technology, as a tool in treatments management. However, the modalities of this monitoring have to be specified and clinical benefit or the cost-effectiveness of a treatment based on this new biomarker has to be evaluated. Finally, the qualitative and quantitative monitoring of CTC could be a non-invasive tool to monitor changes in tumor biology throughout the disease, and thereby improve the understanding of the processes of dissemination and therapeutic resistance.

Combination of biological and morphological parameters for the selection of patients with hepatocellular carcinoma waiting for liver transplantation

BACKGROUND

In the last several years, there has been no agreement on how to possibly expand the Milan criteria (MC) in the selection of patients with hepatocellular carcinoma (HCC) for listing for liver transplant (LT). The aim of the study is to evaluate morphological and biological tumor parameters to identify new expanded criteria for the selection of patients with HCC as candidates for LT.

METHODS

We retrospectively analyzed 158 consecutive patients with HCC who underwent LT.

RESULTS

Twelve (7.6%) recurrences were observed. At multivariate analysis, alpha-fetoprotein (AFP) >400 ng/mL (odds ratio [OR] 8.4, p<0.01) and total tumor diameter (TTD) >8 cm (OR 7.4, p=0.01) were the strongest predictors for recurrence. AFP-TTD criteria resulted in a low five-yr recurrence rate (4.9%) and an increased number of LT compared with the MC (22.2% increase). The five-yr disease-free survival rate was 74.4% in AFP-TTD criteria in patients, with a higher effectiveness in stratifying the cohort with respect to the MC.

CONCLUSIONS

Both AFP and TTD are good independent predictors of HCC recurrence. Their combination appears to obtain a better selection of candidates for LT without worsening patient survival and recurrence rates. This approach allows for an increase in the number of potentially transplantable patients.

Molecular refinement of clinical staging in hepatocellular carcinoma patients evaluated for potentially curative therapies

Aim

VEGF and AFP mRNA determinations in the blood are promising prognostic factors for patients with HCC. This study explores their potential prognostic synergy in a cohort of HCC patients evaluated for potentially curative therapies.

Methods

One hundred twenty-four patients with a diagnosis of HCC were prospectively enrolled in the study. Inclusion criteria were: (a) histological diagnosis of HCC and assessment of tumour grade and (b) determination of AFP mRNA status and VEGF levels in the blood before therapy.

Results

At baseline evaluation, 40% of the study group had AFP mRNA in the blood (AFP mRNA positive), and 35% had VEGF23 pg ml⁻¹ (VEGF positive). Surgery was performed in 58 patients (47%), 54 (43%) had tumour ablation, and 12 had chemoembolisation (10%). Median follow-up and survival of the study group were 19 and 26 months (range, 1 to 60), respectively. The association of AFP mRNA and VEGF proved to be prognostically more accurate than their single use in discriminating the risk of death (ROC curve analysis) and survival probability (Cox analysis). In particular, we identified 3 main molecular stages (0,0001): both negative (3-year survival = 63%), one positive (3-year survival = 40%), both positive (3-year survival = 16%). Multivariate analysis identified BCLC staging, surgery, and molecular staging as the most significant survival variables.

Conclusions

The preoperative determination of AFP mRNA status and VEGF may potentially refine the prognostic evaluation of HCC patients and improve the selection process for potentially curative therapies.

Role of alpha-fetoprotein in selection of patients with hepatocellular carcinoma waiting for liver transplantation: must we reconsider it?

BACKGROUND

Milan criteria (MC) represent the most commonly adopted criteria for the selection of patients with hepatocellular carcinoma (HCC) waiting for liver transplantation (LT). However, MC are exclusively based on morphological aspects. The aim of the present study was to evaluate pre-LT-detectable biological parameters, to compare them with morphological ones in terms of tumor recurrence prediction and patient survival.

METHODS

A cohort of 153 consecutive adult patients who underwent LT for HCC on cirrhosis from January 1999 to March 2009 was retrospectively analyzed.

RESULTS

HCC recurrence was observed in 12 patients (7.8%). At multivariate logistic regression analysis, serum alpha-fetoprotein (AFP) was the unique independent negative risk factor for the development of HCC recurrence (odds ratio 2.0, p=0.03). Adopting a cutoff value of 210 ng/mL, patients who presented serum AFP =210 ng/mL showed a 5-year survival rate of 23.3% versus 76.2% observed in patients with pre-LT serum AFP <210 ng/mL (log-rank test: <0.0001).

CONCLUSIONS

In our experience, AFP was the strongest predictor of HCC recurrence, stronger than tumor morphology. AFP could ameliorate the selection of LT candidates. Further studies to evaluate the combination of morphological and biological criteria are needed.

Disseminated and circulating tumor cells in gastrointestinal oncology

Circulating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers.

An Overview of Biomarkers and Molecular Signatures in HCC

Hepatocellular carcinoma (HCC) is the third most common cause of cancer mortality worldwide. Although most HCCs seem to originate from the accumulation of genetic abnormalities induced by various risk factors, underlying mechanisms of hepatocarcinogenesis remain unclear. Long-term survival of HCC patients is also poor, partly due to HCC recurrence. Although serum alpha-fetoprotein (AFP) level is a useful marker for the detection and monitoring of HCC, AFP levels may remain normal in the patients even with advanced HCC. To identify useful biomarkers for HCC, many studies have been conducted on molecular events such as genetic and epigenetic alterations, and gene expression. This review summarizes recent studies of potential molecular markers for diagnosis and monitoring metastasis or recurrence of HCC.

Melanoma antigen-1 mRNA combined with alpha-fetoprotein mRNA levels in peripheral blood of patients with hepatocellular carcinoma: a predictor of postoperative recurrence or metastasis?

BACKGROUND

The aim of the study was to identify whether melanoma antigen (MAGE)-1 mRNA and alpha-fetoprotein (AFP) mRNA expressed in peripheral blood could be used to predict the recurrence and metastasis of hepatocellular carcinoma (HCC) after hepatectomy.

METHODS

One hundred and forty-two HCC patients underwent hepatectomy. The control group includes 27 patients with chronic virus hepatitis and cirrhosis and 10 healthy volunteers. Peripheral blood samples were collected on the seventh day before operation, seventh day after operation and 30th day after operation. MAGE-1 mRNA and AFP mRNA were tested by nested reverse transcription polymerase chain reaction. Median follow up was 25.5 months (range 4-40 months). Patient survival, disease-free survival and clinicopathological features were compared between patients with positive and negative MAGE-1 mRNA and/or AFP mRNA.

RESULTS

The expression of MAGE-1 mRNA and/or AFP mRNA in peripheral blood was closely correlated to the pathological stage and the positive ratio of tumour cells in the peripheral blood (P < 0.01). There was recurrence and/or metastasis after operation in 55 of 142 HCC patients. Among the 55 patients who had recurrence or metastasis, MAGE-1 mRNA and/or AFP mRNA in peripheral blood were persistently detected after operation in 38 patients and MAGE-1 mRNA and AFP mRNA turned to positive after operation in 14 patients. In contrast, no recurrence was found in 62 patients whose MAGE-1 mRNA and/or AFP mRNA turned to negative after operation. 88.1% (52 of 59) of patients with MAGE-1 mRNA and/or AFP mRNA persistently positive after operation showed recurrence or metastasis, whereas only 3.6% patients (3 of 83) with the negative of MAGE-1 mRNA and/or AFP mRNA after operation showed recurrence or metastasis (P < 0.001).

CONCLUSION

Melanoma antigen-1 mRNA combined with AFP mRNA in peripheral blood after hepatectomy is more sensitive and specific than AFP mRNA singly for predicting the recurrence and metastasis of the HCC patients, whereas preoperative transient detection is not.

Detection of MAGE-1, MAGE-3 and AFP mRNA as multimarker by real-time quantitative PCR assay: a possible predictor of hematogenous micrometastasis of hepatocellular carcinoma

BACKGROUND/AIMS

The aim of this study was to explore the relationship between MAGE-1, MAGE-3 and AFP mRNA in the peripheral blood of patients with hepatocellular carcinoma and micrometastasis in circulation, real-time quantitative-PCR (real-time Q-PCR) assay was applied to detect the expression of the multimarker.

METHODOLOGY

Peripheral blood samples were obtained from 86 patients with hepatocellular carcinoma (HCC) and real-time Q-PCR technique was used to detect the MAGE-1, MAGE-3, and AFP mRNA in the blood.

RESULTS

In 86 tumor specimens, the positivity for MAGE-1, MAGE-3, and AFP genes was 34.9% (30/86), 60.5% (52/86) and 69.8%(60/86) respectively, and all specimens expressed at least one marker. MAGE-1, MAGE-3, and AFP transcripts were detected in 12 (14.0%),18 (20.1%) and 29 (33.7%) of 86 blood specimens from hepatocellular carcinoma patients, respectively, while 45 specimens (52.3%) were positive for at least one marker. In addition, MAGE-1, MAGE-3 and AFP gene transcripts were not detected in any peripheral blood specimens from 25 chronic liver disease patients and 28 normal healthy volunteers. The positive rate correlated with the TNM clinical stages, extrahepatic metastasis and portal vein carcinothrombosis (p<0.05). No correlation was found between tumor size, tumor number, differentiation, serum a-fetoprotein (AFP) and the positive rate.

CONCLUSIONS

Our results indicate that a multimarker real-time Q-PCR assay with cancer-specific markers such as MAGE-1 and MAGE-3 in combination with a hepatocyte-specific AFP marker may be a promising diagnostic tool for monitoring hepato-cellular carcinoma patients with better sensitivity and specificity.

Diagnosing and monitoring hepatocellular carcinoma with alpha-fetoprotein: new aspects and applications

Hepatocellular carcinoma is the 5th most common cancer in the world. Prognosis for this disease is poor since hepatocellular carcinoma is mostly diagnosed at an advanced stage. Serum alpha-fetoprotein (AFP) is one of the most common diagnostic markers for hepatocellular carcinoma. However, its diagnostic value is more and more questioned. Therefore, research has focussed on AFP related parameters (AFP mRNA and AFP glycoforms). The aim of this paper is to review the present knowledge on AFP and its related parameters in diagnosing and monitoring HCC. AFP related parameters can be arranged in two types: AFP mRNA and AFP glycoforms. AFP mRNA is a potentially prognostic marker and AFP mRNA assays are based on PCR techniques. The AFP glycoforms have diagnostic potential and assays are based on isoelectric focussing and lectin affinity electrophoretic methods. Up to now the diagnostic use of the AFP related parameters is limited. Although some of them are recommended as a complementary test, they cannot (yet) replace serum AFP as the golden standard of diagnostic markers for hepatocellular carcinoma.

New perspectives and strategy research biomarkers for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Cirrhosis caused by hepatitis B virus, hepatitis C virus or chronic alcohol intake is associated with major risk. Systematic screening for HCC of asymptomatic patients with cirrhosis is needed for earlier detection of small tumors requiring treatment (liver transplantation, surgical resection, percutaneous techniques). The recommended screening strategy among cirrhotic patients is based on regular liver ultrasonography associated with serum alpha-fetoprotein (AFP) assay. As the performance of AFP is not satisfactory, additional tumoral markers are proposed (des-gamma-carboxyprothrombin, glycosylated AFP-L3 fraction). Currently, diagnosis of HCC in cirrhotic patients includes non-invasive tests (imaging after contrast administration, AFP assay); diagnostic biopsy is performed when imaging is limited. After treatment, tumor recurrence is assessed by regular follow-up (AFP assay and imaging). Despite the lack of accurate markers, recent developments in genomic and proteomic approaches will allow the discovery of new biomarkers for primary tumors, as well as for recurrence. This review summarizes the current state of biomarkers for screening, diagnosis and follow-up of HCC, and highlights new perspectives in the field.

Establishment of multiplexed, microsphere-based flow cytometric assay for multiple human tumor markers

AIM

The multiplexed, microsphere-based flow cytometric assay (MFCA) for multiple human tumor markers was established for the early screening and detection of suspected cancer patients.

METHODS

Covalent coupling of capture antibodies directed against their respective tumor markers to fluorescent microspheres was performed by following the protocols recommended by a commercial corporation with some modifications. The coupling efficiency and cross-reactivity were identified by the Luminex 100 system and associated software. The standard curve was constructed by using serial dilution of recombinant tumor marker standards and was validated by comparison with ELISA for quantifying the tumor markers in serum samples.

RESULTS

The identifications revealed that the coupling procedures were successful without non-specific cross-reactivity and the standard curve was highly efficient. However, it was necessary to ensure the quality control of the coupling process since slight variations in the coupling procedures could profoundly affect the density of capture reagents coupled to the microspheres and consequently adversely affect the assay precision. In addition to its multi-analyte capability, the MFCA system had definite advantages, such as higher reproducibility, greater dynamic range of measurement, and considerably less preparation time and labor over the conventional "gold standard", which was the ELISA.

CONCLUSION

The successful establishment of the MFCA system for the simultaneous detection of multiple tumor markers will provide the foundation for the further study of clinical applications.

Epithelial molecular markers in the peripheral blood of patients with colorectal cancer

Despite the modest improvements in patient survival from colorectal cancer in the last few decades, the overall five-year survival rate remains at 40 to 45 percent. Surgical resection is the mainstay of treatment for colorectal cancer; however, nearly one-half of all patients who undergo a potentially curative resection will relapse because of undetected micrometastasis. The fact that the overall survival rate remains poor strongly suggests that the dissemination of these cells occurs early in the disease process and emphasizes the need for finding feasible diagnostic methods with sufficient sensitivity and specificity. The most commonly used technique for the detection of nucleic acid material of disseminated tumor cells is the polymerase chain reaction. We critically review the literature on DNA and messenger ribonucleic acid molecular markers that have been used for the detection of circulating tumor cells in the peripheral blood of patients with colorectal cancer and other solid tumors as appropriate for comparison. The cytokeratins, particularly cytokeratin 19 and cytokeratin 20, are the most investigated prognostic markers, but even for these questions remain about their clinical value, and hence most recent studies are utilizing a combination of factors. There is an urgent need for standardized isolation and analysis techniques to be adopted thus allowing large-scale, appropriately controlled, multicenter trials to be undertaken on the most promising candidate markers.

Microarray-based identification and RT-PCR test screening for epithelial-specific mRNAs in peripheral blood of patients with colon cancer

BACKGROUND

The efficacy of screening for colorectal cancer using a simple blood-based assay for the detection of tumor cells disseminated in the circulation at an early stage of the disease is gaining positive feedback from several lines of research. This method seems able to reduce colorectal cancer mortality and may replace colonoscopy as the most effective means of detecting colonic lesions.

METHODS

In this work, we present a new microarray-based high-throughput screening method to identifying candidate marker mRNAs for the early detection of epithelial cells diluted in peripheral blood cells. This method includes 1. direct comparison of different samples of colonic mucosa and of blood cells to identify consistent epithelial-specific mRNAs from among 20,000 cDNA assayed by microarray slides; 2. identification of candidate marker mRNAs by data analysis, which allowed selection of only 10 putative differentially expressed genes; 3. Selection of some of the most suitable mRNAs (TMEM69, RANBP3 and PRSS22) that were assayed in blood samples from normal subjects and patients with colon cancer as possible markers for the presence of epithelial cells in the blood, using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Our present results seem to provide an indication, for the first time obtained by genome-scale screening, that a suitable and consistent colon epithelium mRNA marker may be difficult to identify.

CONCLUSION

The design of new approaches to identify such markers is warranted.

Prokaryotic expression of anti-carcinoembryonic single-chain variable fragment and its value in detection of gastric carcinoma cells

AIM: To study the prokaryotic expression of the anti-carcinoembryonic antigen (CEA) single-chain fragment variable (scFv) antibody T84.66 and its specific affinity to gastric cancer cell lines and tissues.

METHODS: The cDNA of anti-CEA scFv antibody was inserted into pCANTAB5E to obtain phage vector T84.66-scFv-pCANTAB5E, and then the vector was transferred into E. coli HB2151. Isopropyl-β-D-thiogalactoside (IPTG) was used to induce the expression of anti-CEA scFv antibody. SDS-PAGE and Western blot were used identify the anti-CEA scFv antibody. Human gastric cancer cells were cultured, and CEA was determined with the obtained scFv by immunohistochemistry in the cells and paraffin-embedded gastric carcinoma tissues.

RESULTS: SDS-PAGE and Western blot showed that the anti-CEA scFv antibody T84.66 was successfully expressed. T84.66 could bind to gastric carcinoma cell lines KATOⅢ, MKN45 and HGC-27, but not to SGC7901, GC803 and BGC823, suggesting that KATOⅢ, MKN45 and HGC-27 cells expressed CEA. For the 42 cases gastric carcinoma tissues, the positive rate of CEA in the early and progressive stage was 55% (6/11) and 61% (19/31), respectively, but no CEA expression was found in the 10 normal cases. CEA expression was significantly different between gastric cancer and normal tissues (P < 0.05).

CONCLUSION: The prokaryotic expression of anti-CEA scFv antibody T84.66 is successfully achieved, and can be used to identify CEA. CEA is highly expressed in gastric cancer, but not in normal mucosa.

Role of blood AFP mRNA and tumor grade in the preoperative prognostic evaluation of patients with hepatocellular carcinoma

AIM

To explore the potential prognostic role of preoperative tumor grade and blood AFP mRNA in a cohort of patients with hepatocellular carcinoma (HCC) eligible for radical therapies according to a well-defined treatment algorithm not including nodule size and number as absolute selection criteria.

METHODS

Fifty patients with a diagnosis of HCC were prospectively enrolled in the study. Inclusion criteria were: (1) histological assessment of tumor grade by means of percutaneous biopsies; (2) determination of AFP mRNA status in the blood; (3) patient's eligibility for radical therapies.

RESULTS

At preoperative evaluation, 54% of the study group had a well-differentiated HCC, 42% had AFP mRNA in the blood, 40% had a tumor larger than 5 cm and 56% had more than one nodule. Surgery (resection or liver transplantation) was performed in 29 patients, while 21 had percutaneous ablation procedures. After a median follow-up of 28 mo, 12-, 24-, and 36-mo survival rates were 78%, 58%, and 51%, respectively. Surgical therapy, performance status and three tumor-related variables (AFP mRNA, HCC grade and gross vascular invasion) resulted as significant survival predictors at univariate analysis. Nodule size and number did not perform as significant prognosticators. Multivariate study selected only surgical therapy and a biologically early HCC profile (AFP mRNA negative and well-differentiated tumor without gross vascular invasion) as independent survival variables.

CONCLUSION

The preoperative determination of tumor grade and blood AFP mRNA status may potentially refine the prognostic evaluation of HCC patients and improve the selection process for radical therapies.

Detecting AFP mRNA in peripheral blood of the patients with hepatocellular carcinoma, liver cirrhosis and hepatitis

BACKGROUND

The low frequency of disseminated carcinoma cells in the blood now makes immunomagnetic bead sorting and reverse transcriptase-polymerase chain reaction (RT-PCR) technique more popular.

METHODS

Three milliliters of peripheral blood were collected from 91 patients and 18 normal donors. The circulating carcinoma cells were enriched with CD45 and Ber-EP4 immunomagnetic beads. The alpha-fetoprotein (AFP) mRNA was amplified with nested RT-PCR.

RESULTS

The total positive detection rate was 72.1%, 43.8%, 25.0%, 100%, and 66.7% in patients with hepatocellular carcinoma (HCC) untreated, liver cirrhosis (LC), hepatitis, metastasis liver cancer, and postsurgery of hepatocellular carcinoma, respectively. There was a significant difference among the patients with HCC, LC and hepatitis (HCC vs. LC, P<0.05; HCC vs. hepatitis, P<0.01) and between Class A and B of the HCC patients (P<0.05). Meanwhile, AFP mRNA was markedly expressed in HCC patients compared to the patients with no HCC (LC and hepatitis). The levels of aspartate transaminase (AST) and gamma-glutamyltranspeptidase (GGT) were significantly different in AFP mRNA-positive patients with autoimmune chronic active hepatitis B (CAHB) or LC in contrast to the corresponding negative patients.

CONCLUSION

Combining negative and positive immunomagnetic bead sorting and RT-PCR technique can effectively detect circulating tumor cells. AFP mRNA is a more reliable marker of metastasis compared to serum AFP.

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