Quantitative analysis of alpha-fetoprotein mRNA in circulating peripheral blood of patients with hepatocellular and alpha-fetoprotein-producing gastric carcinomas

Basic techniques in endoscopic ultrasound-guided fine needle aspiration for solid lesions: Adverse events and avoiding them

Endoscopic ultrasound (EUS) guided fine-needle aspiration (FNA) is often the preferred technique for tissue acquisition in the diagnosis of suspected intrathoracic and intraabdominal pathology. Although EUS FNA is a safe and accurate procedure, it has been associated with a low risk of adverse events. The unique properties of the echoendoscope and its ability to acquire tissue outside of the gastrointestinal lumen impart risks that are not associated with routine endoscopic procedures. In this review, we discuss the risk of perforation related to the echoendoscope itself and adverse events related to FNA of solid masses including infections, bleeding, pancreatitis and pancreatic duct leak, bile duct leak and tumor seeding. We also provide tips on how to avoid the most common adverse events related to EUS-FNA.

Endoscopic ultrasound staging of cholangiocarcinoma

PURPOSE OF REVIEW

Cholangiocarcinoma is a malignancy arising from biliary tract epithelium that is increasing in incidence and is associated with a poor prognosis. The difficulty in diagnosis and relatively poor staging accuracy complicate management. In this review we examine the utility of endoscopic ultrasound (EUS), which is increasingly used in this setting to overcome the limitations of other imaging and biopsy techniques.

RECENT FINDINGS

Inherent limitations of current approaches to cholangiocarcinoma diagnosis and staging have driven the pursuit of new technologies including EUS. However, there remains a relative paucity of data and some uncertainty as to the role of EUS within the diagnostic algorithm for patients with suspected or known cholangiocarcinoma. In addition, there is controversy regarding the role of EUS fine-needle aspiration, the findings of which may enhance diagnosis, but may also predispose to tumor seeding and iatrogenic upstaging.

SUMMARY

An emerging indication for EUS is the diagnosis and staging of cholangiocarcinoma. This information may be used to help guide patient care and improve outcomes, but may also be employed in a manner that risks patient well being.

Prospective cytological assessment of gastrointestinal luminal fluid acquired during EUS: a potential source of false-positive FNA and needle tract seeding

OBJECTIVES

Endoscopic ultrasound (EUS) fine needle aspiration (FNA) can result in false-positive cytology and can also cause needle tract seeding. Our goal was to evaluate a potential cause, namely, the presence of malignant cells within gastrointestinal (GI) luminal fluid, either as a result of tumor sloughing from luminal cancers or secondary to FNA of extraluminal sites.

METHODS

During EUS, luminal fluid that is usually aspirated through the echoendoscope suction channel and discarded was instead submitted for cytological analysis among patients with cancer and benign disease. Pre- and post-FNA luminal fluid samples were collected to discern the role of FNA in inducing a positive cytology. When not performing FNA, one sample was collected for the entire examination. The final diagnosis was based on strict clinicopathological criteria and >or=2-year follow-up. This study was conducted in a tertiary referral center.

RESULTS

We assessed the prevalence of luminal fluid-positive cytology among patients with luminal (e.g., esophageal), extraluminal (e.g., pancreatic), and benign disease. Among the 140 patients prospectively enrolled with sufficient sampling and follow-up, an examination of luminal fluid cytology showed positive results for malignancy in luminal and extraluminal cancer patients, 48 and 10%, respectively. This included 8 out of 23 esophageal, 4 of 5 gastric, and 9 of 15 rectal cancers. The positive luminal fluid cytology rate with luminal cancers was not affected by performing FNA. Post-FNA luminal fluid cytology was positive in 3 out of 26 with pancreatic cancers. Cytological examination of luminal fluid aspirates did not demonstrate malignant cells in any patient with nonmalignant disease.

CONCLUSIONS

Malignant cells are commonly present in the GI luminal fluid of patients with luminal cancers and can also be found in patients with pancreatic cancer after EUS FNA. Further study is needed to determine the impact of these findings on cytological interpretation, staging, risk of needle tract seeding, and patient care and outcomes.

Association between recurrence of hepatocellular carcinoma and alpha-fetoprotein messenger RNA levels in peripheral blood

PURPOSE

Intra- and extrahepatic recurrence is common, even after curative resection for hepatocellular carcinoma (HCC), suggesting preoperative or intraoperative tumor cell dissemination. Reverse transcription - polymerase chain reaction (RT-PCR) for alpha-fetoprotein (AFP) is used to detect circulating liver cancer cells. We previously developed a quantitative method that allows estimation of the AFP mRNA level by real-time PCR. In the present study, we used this method to measure the AFP mRNA level before and after resection of HCC, then correlated the findings with various clinicopathological characteristics and prognosis.

METHODS

We prospectively examined peripheral blood samples from 38 patients with HCC, and bone marrow aspirate from 25 of these patients. As a control, we examined bone marrow from 20 patients with benign diseases. The follow-up period ranged from 32 to 66 months. Real-time RT-PCR was used to detect AFP mRNA levels in the samples.

RESULTS

AFP was expressed in 9 (23.7%) of the 38 peripheral blood samples. The detection of AFP mRNA was significantly correlated with extrahepatic metastasis after primary surgery, and a shorter disease-free survival time (P = 0.0245 each). Bone marrow samples were defined as positive if they expressed AFP mRNA at levels higher than the maximum expressed level in the controls, because only 1 (5%) of the 20 control bone marrow samples had low AFP mRNA expression. Using this cutoff level, 12 (48%) of the 25 patients with HCC had positivity for AFP mRNA. The results of bone marrow RT-PCR did not correlate with the clinocopathological characteristics of prognosis.

CONCLUSIONS

Using real-time PCR to measure the AFP mRNA level in blood, but not bone marrow, could be useful for predicting postoperative tumor recurrence.

Real-time quantification of AFP mRNA to assess hematogenous dissemination after transarterial chemoembolization of hepatocellular carcinoma

OBJECTIVE

To determine whether the number of hepatocytes containing AFP mRNA shed into the bloodstream during transarterial chemoembolization (TAE) affects the incidence and pattern of recurrence of hepatocellular carcinoma (HCC).

PATIENTS AND METHODS

We developed a Taqman procedure to quantify AFP mRNA prospectively in 52 consecutive patients before and after TAE. Results are expressed in hepatocytes /mL.

RESULTS

Thirteen of the patients (24.5%) were positive for AFP mRNA (42 +/- 19 hepatocytes/mL) before TAE and 13 (24.5%) (80 +/- 32 hepatocytes/mL) after TAE; the difference was not significant. The presence of AFP mRNA in the bloodstream before TAE was associated with larger nodules (85.2 +/- 73.8 mm versus 34.8 +/- 26.1 mm; P = 0.006). Six of the patients were excluded from the analysis because they underwent curative surgery or were lost to follow-up. The circulating levels of AFP mRNA released in the 46 remaining patients after TAE did not affect metastasis-free survival. A significant number of extrahepatic metastases were found in patients exhibiting at least 1 AFP mRNA-positive blood sample either before or after TAE. However, the TAE procedure did not increase the risk of extrahepatic recurrences.

CONCLUSION

Cells containing AFP mRNA are inconsistently released into the circulation during TAE. The amount of these cells released does not affect the recurrence of HCC.

Molecular characterization of minimal residual cancer cells in patients with solid tumors

The failure to reduce the mortality of patients with solid tumors is mainly a result of the early dissemination of cancer cells to secondary sites, which is usually missed by conventional diagnostic procedures used for tumor staging. PCR was shown to be superior to conventional techniques in detecting circulating tumor cells and micrometastases allowing the identification of one tumor cell in up to 10(7) normal cells in various sources such as blood, bone marrow, lymph nodes, urine or stool. The methods used are based on the detection of either genomic alterations in oncogenes and tumor suppressor genes or on the mRNA expression of tissue-specific and tumor-associated genes. The additional implementation of techniques for cancer cell purification had a significant impact on analytical sensitivity and specificity of MRCC detection. For patients with e.g. melanoma, breast, colorectal or prostate cancer it was demonstrated that the presence of disseminated cancer cells defines a subgroup of patients with reduced time to recurrence. The possibility to use easily accessible body fluids as a source for MRCC detection enables longitudinal observations of the disease. In this review we discuss the potential of molecular characterization of MRCC as a tool to improve prognostication, therapy selection and drug targeting as well as therapy monitoring.

Significant down-regulation of alpha-albumin in human hepatoma and its implication

The potential association of alpha-albumin (ALF) with hepatocellular carcinoma (HCC) was investigated. Expression of ALF was significantly reduced in HCC tumor tissue as compared with the paired peritumor tissue from 16 patients and in four HCC cell lines as compared with normal hepatocytes. ALF mRNA was also down-expressed in circulating HCC cells compared to circulating normal hepatocytes. The proliferation of Hep3B cells was inhibited by over-expression of ALF. Taken together, ALF is significantly down-regulated in HCC, and this might facilitate the proliferation of HCC. Thus, detection of ALF mRNA, in addition to that of alpha-fetoprotein (AFP) mRNA, might help to distinguish normal or malignant hepatocytes in peripheral blood.

Effects of microenvironmental extracellular pH and extracellular matrix proteins on angiostatin's activity and on intracellular pH

Antiangiogenic agents target migratory and proliferative endothelial cells (EC) in the process of forming new vessels, resulting in growth inhibition or cell death. Here we have shown that the antiangiogenic activity of angiostatin on EC is enhanced in culture when the microenvironmental extracellular pH (pH(e)) is reduced to levels similar to that of many tumors. In a migration/scratch assay and during tube formation, angiostatin in combination with reduced pH(e) synergistically resulted in an increased EC death--an effect not seen with either stimulus individually. Lowering of pH(e) decreased intracellular pH (pH(i)), and a further lowering of pH(i) occurred when low pH(e) was combined with angiostatin. These data suggest that low pH(e) plays a role in the relative specificity and efficacy of angiostatin for tumor neovasculature and indicate roles for both pH(e) and pH(i) in the mechanism of angiostatin action. A receptor for angiostatin, the alpha-subunit of ATP synthase, was found on the surface of EC. We show that cell surface receptor distribution is increased on Matrigel, a basement-like matrix, as opposed to fibronectin or RGD peptide substrates, and redistributed to a more punctuate appearance at low pH(e). Furthermore, positive cell surface histochemical staining for alpha-ATP synthase was blocked by preincubation with angiostatin. These data indicate that substrate and pH(e) are critical parameters in the evaluation of this antiangiogenic substance, and probably for others as well.

Gastrin-induced gene expression in oxyntic mucosa and ECL cells of rat stomach

The histamine-producing ECL cells are numerous in the acid-producing (oxyntic) mucosa. They respond to gastrin by secretion of histamine that acts on parietal cells to produce acid. In addition, gastrin has a trophic effect on the oxyntic mucosa which is exerted on stem cells and ECL cells. To elucidate the molecular actions of gastrin on the stomach we attempted to identify genes that are regulated by gastrin in oxyntic mucosa and in isolated ECL cells. Differential display polymerase chain reaction was used to identify mRNAs that are differentially expressed in rats that are hypergastrinemic after treatment with the proton pump inhibitor omeprazole for 48 h compared with rats that are hypogastrinemic after 24 h fasting. Differences in mRNA levels were confirmed by Northern blot analysis (comparing mRNA from fasted rats, omeprazole-treated rats and rats treated with omeprazole + the CCK2 (cholecystokinin) receptor antagonist YF476). The cDNAs were identified by sequencing followed by data base search. Hypergastrinemia induced by omeprazole treatment resulted in overexpression of mRNA for histidine decarboxylase, fetuin, pepsinogen and cytochrome P450 in the oxyntic mucosa. This was prevented by CCK2 receptor blockade. In isolated ECL cells gastrin upregulated mRNAs for histidine decarboxylase and synaptotagmin V as well as one mRNA transcript without known homology.