Prognostic significance of pathological and biological factors in hepatocellular carcinoma

Enhanced DNA Repair Pathway is Associated with Cell Proliferation and Worse Survival in Hepatocellular Carcinoma (HCC)

Simple Summary

We studied the relationship between enhancement of DNA repair and cancer aggressiveness, tumor immune microenvironment, and patient survival in 749 hepatocellular carcinoma (HCC) patients from 5 cohorts using a DNA repair pathway score. We show that the DNA repair pathway was enhanced by the stepwise carcinogenic process of HCC, notably in grade 3 compared to grade 1 or 2 HCC. DNA repair high HCC was associated with worse survival, elevated intratumor heterogeneity, and mutation load, but not with the fraction of immune cell infiltration nor cytolytic activity. The expression of proliferation- and other cancer aggressiveness-related gene sets was also increased. Interestingly, these features were more pronounced in low-grade compared to high-grade HCC. In conclusion, the DNA repair score may be used to understand the role of DNA repair pathways in patient prognosis and treatment sensitivity and be used to improve patient outcome. To our knowledge, this is the first study using DNA repair pathway-related gene set expression data to examine and validate the clinical relevance of DNA repair pathway activity in HCC.

Abstract

Hepatocellular carcinoma (HCC) is one of the most common malignancies and a leading cause of cancer-related deaths worldwide. In this study, a total of 749 HCC patients from 5 cohorts were studied to examine the relationships between enhancement of DNA repair and cancer aggressiveness, tumor immune microenvironment, and patient survival in HCC, utilizing a DNA repair pathway score. Our findings suggest that the DNA repair pathway was not only enhanced by the stepwise carcinogenic process of HCC, but also significantly enhanced in grade 3 HCC compared with grade 1 and 2 tumors. DNA repair high HCC was associated with worse survival, elevated intratumor heterogeneity, and mutation load, but not with the fraction of immune cell infiltration nor immune response. HCC tumors with a DNA repair high score enriched the cell proliferation- and other cancer aggressiveness-related gene sets. Interestingly, these features were more pronounced in grade 1 and 2 HCC compared to grade 3 HCC. To our knowledge, this is the first study to use DNA repair pathway-related gene set expression data to examine and validate the clinical relevance of DNA repair pathway activity in HCC. The DNA repair score may be used to better understand and predict prognosis in HCC.

Causal Modeling of Cancer-Stromal Communication Identifies PAPPA as a Novel Stroma-Secreted Factor Activating NFκB Signaling in Hepatocellular Carcinoma

Inter-cellular communication with stromal cells is vital for cancer cells. Molecules involved in the communication are potential drug targets. To identify them systematically, we applied a systems level analysis that combined reverse network engineering with causal effect estimation. Using only observational transcriptome profiles we searched for paracrine factors sending messages from activated hepatic stellate cells (HSC) to hepatocellular carcinoma (HCC) cells. We condensed these messages to predict ten proteins that, acting in concert, cause the majority of the gene expression changes observed in HCC cells. Among the 10 paracrine factors were both known and unknown cancer promoting stromal factors, the former including Placental Growth Factor (PGF) and Periostin (POSTN), while Pregnancy-Associated Plasma Protein A (PAPPA) was among the latter. Further support for the predicted effect of PAPPA on HCC cells came from both in vitro studies that showed PAPPA to contribute to the activation of NFκB signaling, and clinical data, which linked higher expression levels of PAPPA to advanced stage HCC. In summary, this study demonstrates the potential of causal modeling in combination with a condensation step borrowed from gene set analysis [Model-based Gene Set Analysis (MGSA)] in the identification of stromal signaling molecules influencing the cancer phenotype.

All living cells rely on communication with other cells to ensure their function and survival. Molecular signals are sent among cells of the same cell type and from cells of one cell type to another. In cancer, not only the cancer cells themselves are responsible for the malignancy, but also stromal (non-cancerous) cells and the molecular signals they send to cancer cells are important factors that determine the severity and outcome of the disease. Therefore, the identification of stromal signals and their influence on cancer cells is important for the development of novel treatment strategies. With a computational systems biology model of stroma-cancer cell communication, we have compiled a set of ten proteins secreted by stromal cells that shape the cancer phenotype. Most importantly, our causal analysis uncovered Pregnancy-Associated Plasma Protein A (PAPPA) as a novel paracrine inducer of the pro-tumorigenic NFκB signaling pathway. In liver cancer patients, higher levels of PAPPA protein indicate a more progressed tumor stage, confirming its clinical relevance.

Clinical usefulness of (18) F-fluorodeoxyglucose positron emission tomography/computed tomography for patients with primary liver cancer with special reference to rare histological types, hepatocellular carcinoma with sarcomatous change and combined hepatocellular and cholangiocarcinoma

AIM

The role of (18) F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the diagnosis and staging of primary liver cancer has been demonstrated in several reports. However, no preoperative evaluations of sarcomatous hepatocellular carcinoma (HCC) and combined hepatocellular and cholangiocarcinoma (cHCC-CC) with FDG-PET have been reported so far.

METHODS

Fifty-three HCC patients and three cHCC-CC patients who received liver resection or living-donor liver transplantation were enrolled in this study. All 56 patients had undergone preoperative FDG-PET, and a total of 67 HCC and three cHCC-CC were analyzed histologically. The relationship between clinicopathological features and the maximum standardized uptake value (SUVmax) of tumors were evaluated.

RESULTS

The detection rate of HCC by FDG-PET was 43.3 %, and the sensitivity of FDG-PET for the detection of HCC was significantly associated with tumor differentiation, tumor size and microvascular invasion. All three cHCC-CC were detected by FDG-PET. The SUVmax values of the three sarcomatous HCC (SUVmax 14.1, 18.6 and 25.0) and the three cHCC-CC (SUVmax 9.9, 12.0 and 13.0) were higher than that of the poorly differentiated HCC (mean SUVmax 5.7 ± 2.3).

CONCLUSION

SUVmax may be a useful diagnostic tool for the preoperative evaluation of the aggressiveness of primary liver cancers such as sarcomatous HCC and cHCC-CC.

The effect of long-term supplementation with branched-chain amino acid granules in patients with hepatitis C virus-related hepatocellular carcinoma after radiofrequency thermal ablation

GOALS

To elucidate whether long-term supplementation with branched-chain amino acid (BCAA) granules improves overall survival (OS) and recurrence-free survival (RFS) after radiofrequency thermal ablation (RFA) in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC)≤3 cm in diameter with up to 3 nodules and a serum albumin level before RFA of ≤3.5 g/dL.

BACKGROUND

Whether BCAA treatment after curative RFA for patients with HCV-related HCC improves OS and RFS remains unclear.

STUDY

We compared the OS rate and the RFS rate between the BCAA group (n=115) and the control group (n=141). We also examined factors contributing to OS and RFS.

RESULTS

The 1 and 3 years OS rates after RFA were 94.0% and 70.0%, respectively, in the BCAA group, and 94.0% and 49.8%, respectively, in the control group (P=0.001). The corresponding RFS rates 1 and 3 years after RFA were 61.8% and 28.0%, respectively, in the BCAA group, and 52.0% and 12.0%, respectively, in the control group (P=0.013). In the multivariate analysis, in terms of OS, BCAA treatment, and serum albumin level of ≥3.4 g/dL, and in terms of RFS, age 70 years or older, BCAA treatment, and a serum albumin level of ≥3.4 g/dL were significant independent factors, respectively.

CONCLUSIONS

BCAA treatment may improve OS and RFS after RFA in patients with HCV-related HCC≤3 cm in diameter with up to 3 nodules and a serum albumin level before RFA of 3.5 g/dL.

Transcatheter arterial infusion chemotherapy prior to radiofrequency thermal ablation for single hepatocellular carcinoma reduces the risk of intrahepatic distant recurrence

The aim of the present study was to elucidate the effectiveness of transcatheter arterial infusion chemotherapy (TAI) of the whole liver using an epirubicin-mitomycin-lipiodol emulsion, prior to radiofrequency thermal ablation (RFA), in preventing intrahepatic distant recurrence (IDR) from single hepatocellular carcinoma (HCC). Of the 269 consecutive patients who underwent RFA in our institute for single HCC, a total of 182 patients were analyzed in the present study. The primary endpoint was comparison of the post-RFA IDR-free survival rates in patients treated using TAI with an epirubicin-mitomycin-lipiodol emulsion via the proper hepatic artery (TAI-EML) prior to RFA, and patients that received lipiodol infusion-alone prior to RFA. The secondary endpoints were local tumor progression (LTP) and overall survival (OS). Lipiodol infusion-alone prior to RFA was performed in 88 patients and TAI-EML prior to RFA in 94 patients. The mean tumor size was 2.06 cm (range, 0.9-3.2 cm) in the TAI group and 1.97 cm (range, 0.9-3.3 cm) in the lipiodol-alone group, respectively. The cumulative IDR-free survival rates at 1, 2 and 3 years were 74.0, 50.8 and 34.9%, respectively, in the lipiodol-alone group, and 90.8, 74.8 and 70.0%, respectively, in the TAI group (P<0.001). In terms of the OS, there was a significant difference between these two groups (P=0.048), although there was no significant difference in terms of the LTP (P=0.145). We concluded that TAI-EML prior to RFA appears to be useful in reducing post-RFA IDR and may contribute to improved survival rates.

Evaluation of hepatocellular carcinoma by contrast-enhanced sonography: correlation with pathologic differentiation

OBJECTIVES

The purpose of this study was to determine whether contrast-enhanced sonography can be used to differentiate histopathologic grades of hepatocellular carcinoma.

METHODS

This study included 54 patients with hepatocellular carcinomas. All patients underwent fundamental and contrast-enhanced sonographic examinations. Auto-tracking contrast quantification software was used to determine the contrast arrival time, time to peak, peak intensity, contrast-enhanced time, wash-out time, enhancement slope, and clearance slope of the lesions. All lesions were confirmed by surgery. The hepatocellular carcinoma lesions were divided into 2 groups according to the World Health Organization grading system: group 1 (well-differentiated hepatocellular carcinomas) and group 2 (moderately to poorly differentiated carcinomas). The enhancement parameters between the groups were compared using a Student t test.

RESULTS

Fourteen of 20 well-differentiated lesions showed a "fast-in, slow-out" enhancement pattern, whereas 6 showed a "fast-in, fast-out" pattern. Thirty-three of 34 moderately to poorly differentiated lesions showed a fast-in, fast-out pattern, whereas only 1 showed a fast-in, slow-out pattern. The differences in the time to peak, contrast-enhanced time, wash-out time, enhancement slope, and clearance slope between the groups were statistically significant (P < .05), whereas the differences in the arrival time and peak intensity were not significant (P > .05).

CONCLUSIONS

The contrast patterns of well-differentiated and moderately to poorly differentiated hepatocellular carcinomas were quite different on contrast-enhanced sonography. The time to peak, contrast-enhanced time, and wash-out time of the well-differentiated hepatocellular carcinomas were longer than those of the moderately to poorly differentiated carcinomas, whereas the enhancement slope and clearance slope of the well-differentiated lesions were lower those that of the moderately to poorly differentiated lesions.

Intrahepatic cholangiocarcinoma and hepatocellular carcinoma: differential diagnosis with contrast-enhanced ultrasound

OBJECTIVE

We assessed the usefulness of contrast-enhanced ultrasound (CEUS) in the differentiation of intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

METHODS

The CEUS enhancement patterns of 50 ICCs were retrospectively analysed and compared with 50 HCCs. Two readers independently reviewed the baseline ultrasound (BUS) and CEUS images and the diagnostic performances were evaluated by receiver operating characteristic (ROC) analysis. Time-intensity curves (TIC) were plotted for quantification analysis.

RESULTS

In the arterial phase, peripheral rim-like hyperenhancement, heterogeneous hyperenhancement, homogeneous hyperenhancement and heterogeneous hypoenhancement were found in 25, 10, 3 and 12 of the ICCs versus 2, 29, 19 and 0 of the HCCs (P < 0.001), respectively. The diagnostic performance of both readers in terms of the area under the ROC curve (0.745 vs. 0.933 for reader 1, and 0.803 vs. 0.911 for reader 2), sensitivity (28% vs. 90%, and 44% vs. 82%) and accuracy (64% vs. 90%, and 71% vs. 90%) improved significantly after CEUS (all P < 0.05). The interobserver agreement increased from kappa = 0.575 at BUS to kappa = 0.720 after CEUS. TICs demonstrated that the intensities of the peripheral and central portions of the ICCs were lower than those of HCCs (both P < 0.05).

CONCLUSION

CEUS improves the diagnostic performance significantly in the differentiation between ICC and HCC.

Systemic therapy for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is currently the fifth most common solid tumor worldwide and the third leading cause of cancer-related death. Eighty percent of new cases occur in developing countries, but the incidence is rising in economically developed regions including Japan, Western Europe, and the United States. More than 80% of patients present with advanced or unresectable disease, and for those patients who do undergo resection, the recurrence rates can be as high as 50% at 2 years. Thus, a large number of patients will seek systemic therapy. Systemic cytotoxic chemotherapy is largely ineffective and can have significant toxicity in patients with underlying liver dysfunction. Newer biologic agents that target molecular abnormalities common to HCC may improve the clinical outcome in patients with HCC.

GRP-induced up-regulation of Hsp72 promotes CD16+/94+ natural killer cell binding to colon cancer cells causing tumor cell cytolysis

Gastrin-releasing peptide (GRP) and its receptor (GRPR) are not normally expressed by epithelial cells lining the adult human colon. However post malignant transformation both GRP and its receptor are aberrantly expressed in the colon where we have previously shown they act to retard metastasis by enhancing tumor cell attachment to the extracellular matrix. In the present study, we show that GRP signaling via its cognate receptor when both are aberrantly expressed in human colon cancer cells causes heat shock protein 72 (Hsp72) to be expressed. We show that GRP/GRPR induces expression of Hsp72 by signaling via focal adhesion kinase. When expressed, Hsp72 promotes the binding of CD16+ and CD94+ natural killer cells, resulting in tumor cell cytolysis. These findings demonstrate the presence of a novel mechanism whereby aberrantly expressed GRP/GRPR in human colorectal cancer attenuates tumor progression and may promote a favorable outcome.

Gastrin-releasing peptide mediates its morphogenic properties in human colon cancer by upregulating intracellular adhesion protein-1 (ICAM-1) via focal adhesion kinase

Gastrin-releasing peptide (GRP) and its receptor (GRPR) act as morphogens when expressed in colorectal cancer (CRC), promoting the assumption of a better differentiated phenotype by regulating cell motility in the context of remodeling and retarding tumor cell metastasis by enhancing cell-matrix attachment. Although we have shown that these processes are mediated by focal adhesion kinase (FAK), the downstream target(s) of GRP-induced FAK activation are not known. Since osteoblast differentiation is mediated by FAK-initiated upregulation of ICAM-1 (Nakayamada S, Okada Y, Saito K, Tamura M, Tanaka Y. J Biol Chem 278: 45368-45374, 2003), we determined whether GRP-induced activation of FAK alters ICAM-1 expression in CRC and, if so, determined the contribution of ICAM-1 to mediating GRP's morphogenic properties. Caco-2 and HT-29 cells variably express GRP/GRPR. These cells only express ICAM-1 when GRPR are present. In human CRC, GRPR and ICAM-1 are only expressed by better differentiated tumor cells, with ICAM-1 located at the basolateral membrane. ICAM-1 expression was only observed subsequent to GRPR signaling via FAK. To study the effect of ICAM-1 expression on tumor cell motility, CRC cells expressing GRP, GRPR, and ICAM-1 were cultured in the presence and absence of GRPR antagonist or monoclonal antibody to ICAM-1. CRC cells engaged in directed motility in the context of remodeling and were highly adherent to the extracellular matrix, only in the absence of antagonist or ICAM-1 antibody. These data indicate that GRP upregulation of ICAM-1 via FAK promotes tumor cell motility and attachment to the extracellular matrix.

Correlation between enhancement pattern of hepatocellular carcinoma on real-time contrast-enhanced ultrasound and tumour cellular differentiation on histopathology

The objective of this study was to evaluate the correlation between the enhancement pattern of hepatocellular carcinoma (HCC) on contrast-enhanced ultrasound (CEUS) and tumour cellular differentiation on histopathology. 189 HCC lesions in 189 patients were retrospectively evaluated with CEUS and histopathological examination. CEUS was performed with SonoVue and contrast pulse sequencing. Histopathological diagnoses were made according to the Edmonson grading system. Significant differences were shown between the time that the HCC became hypoenhancing or remained echogenic in late phase and tumour cellular differentiation (p = 0.006; p = 0.036), but not with the time of commencement of hyperenhancing or commencement of isoenhancing in arterial phase and portal phase (p = 0.164, p = 0.113; p = 0.186, p = 0.070). The timing of HCC becoming hypoenhancing on CEUS is correlated with tumour cellular differentiation; well differentiated tumours wash out more slowly than poorly differentiated ones.

Hepatoma-derived growth factor is a novel prognostic factor for hepatocellular carcinoma

BACKGROUND

Hepatoma-derived growth factor (HDGF) is involved in hepatocarcinogenesis, as well as in liver development and regeneration. This study investigated the correlation of HDGF expression with differentiation and prognosis of hepatocellular carcinoma (HCC).

METHODS

HDGF expression in 100 patients with HCC (81 men and 19 women) with ages ranging from 34 to 81 years (median, 61 years) receiving surgical treatment was analyzed by immunohistochemistry. HDGF messenger RNA expression was evaluated in 10 cases by reverse transcription-polymerase chain reaction. The immunostaining pattern in HCCs was categorized as a positive HDGF index (showing positive staining in >90% of tumor cells in both nucleus and cytoplasm) or a negative HDGF index (all others).

RESULTS

Twenty-seven cases (27%) showed a positive and 73 (73%) showed a negative HDGF index. HDGF messenger RNA expression was significantly higher in four cases with a positive HDGF index than in six with a negative index. Cases with well-differentiated histological characteristics showed a higher rate of positive HDGF index than those with a poorly differentiated subtype. Univariate and multivariate analysis revealed significantly poorer disease-free and overall survivals in patients with a positive HDGF index compared with patients with a negative index.

CONCLUSIONS

These findings suggest the potential utility of HDGF immunohistochemistry in determining the prognosis of HCC.

Hepatitis C virus-NS3P in relation to p53, p21waf, mdm2, p21-ras and c-erbB2 in hepatocarcinogenesis

BACKGROUND

The non-structural protein 3 (NS3P) of hepatitis C virus (HCV) genome was linked to the neoplastic transformation of normal hepatocytes in chronically infected patients. However, the exact mechanisms involved in this process are unidentified yet, especially in the Egyptian population where the commonest type is genotype 4.

METHODS

We investigated 32 HCV reverse transcriptase-polymerase chain reaction (RT-PCR) positive hepatocellular carcinoma (HCC) cases and 18 morphologically normal hepatic tissues distant to tumors (MNT) for the correlation between HCV-NS3P, p53, p21(waf), mdm2, p21ras and c-erbB2 and DNA content by immunohistochemistry and image analysis.

RESULTS

The NS3P expression was lower in HCC (65.6%) than in MNT (94.4%) patients. The expression level of studied genes in HCC was: p53 (56.25%), p21(waf) (43.7%), mdm2 (59.4%), p21-ras (73.3%) and c-erbB2 (75%). Whereas in MNT, it was 22.2, 61.1, 44.4, 41.2 and 77.8%, respectively. The NS3P expression showed a significant correlation with the presence of cirrhosis, chronic active hepatitis (CAH) and tumor grade (P < 0.05). c-erbB2 overexpression and p21(waf) loss were higher in MNT than in HCC patients, however, this did not reach a statistically significant level. There was a statistically significant correlation between NS3P, c-erbB2 and p21(waf) (P < 0.01). There was also a significant correlation between p21(waf) loss and CAH (P = 0.01) as well as between mdm2, c-erbB2 and cirrhosis (P = 0.025 and 0.001) in HCC cases. There was a statistically significant difference in the ploidy status between HCC and MNT, but there was no significant relationship between the ploidy status and other clinicopathological features.

CONCLUSION

The carcinogenic effect of NS3P is probably exerted at an early stage of HCC possibly through a pathway involving c-erbB2 and p21(waf) alterations. In contrast, p53, p21ras and mdm2 alterations are late events in hepatocarcinogenesis and are usually associated with an aggressive phenotype.

Critical evaluation of the different staging systems for hepatocellular carcinoma

BACKGROUND

Diagnostic and therapeutic options for hepatocellular carcinoma (HCC) have improved substantially in recent years. A number of new palliative and potentially curative treatment strategies are now available. However, evaluation of the therapeutic modalities and assessment of the prognosis of HCC remain difficult owing to the lack of consensus on a single staging system and the availability of a number of new staging systems, each claiming to be the most appropriate.

METHODS

The most frequently used staging systems for HCC are presented here. Their ability to stratify patients into different treatment groups and to define prognosis are discussed. In addition, the advantages and disadvantages of each system are analysed.

RESULTS AND CONCLUSION

None of the currently used staging systems fulfils all the requirements for stratification of patients with HCC into groups of different prognosis and therapeutic recommendations. An international agreement on a single staging system is urgently needed in order to permit comparable randomized clinical trials. Only in this way will the outcome for those with HCC be improved.

Phosphorylation of focal adhesion kinase tyrosine 397 critically mediates gastrin-releasing peptide's morphogenic properties

We have proposed that gastrin-releasing peptide (GRP) and its receptor (GRP-R) are morphogens that when aberrantly re-expressed in colon cancer promote tumor cell differentiation and retard metastasis. Because circumstantial evidence suggested that these properties were mediated via focal adhesion kinase (FAK), the purpose of this study was to elucidate the role of GRP-induced activation of this enzyme on properties fundamental to metastasis including cell attachment, motility, and deformability. To do this, we studied 293 cells, a non-malignant epithelial cell line that we show expresses GRP and GRPR. To dissect out the role of FAK, 293 cells were modified to inducibly express the dominant negative enzyme FAK-related non-kinase (FRNK) under control of a Tet-On (i.e., doxycycline-sensitive) promoter. Under serum-free conditions, GRP acting in an autocrine manner caused FAK to be phosphorylated at Y397; and this could be completely inhibited either by incubating with the specific GRP-R antagonist D-Phe(6)(bombesin) methyl ester, or by upregulating FRNK using doxycycline. To measure cell attachment, we designed a cone-plate viscometer that recorded the shear stress required to detach cells from their underlying matrix. To assess motility, confluent cells were wounded and behavior assessed by time-lapse photography. To measure deformability, we recorded the ability of cells to be completely drawn into a micropipette <50% the size of the non-deformed cell. Control 293 cells adhered more avidly to their underlying matrix, rapidly remodeled wounded tissues without any increase in overall proliferation, and were less distensible than cells treated with antagonist or doxycycline. Thus, these findings suggest that expression of GRP/GRPR in cancer inhibits metastasis by enhancing cell attachment to the matrix, regulating motility in the context of remodeling, and decreasing deformability.

Expression of GRP and its receptor in well-differentiated colon cancer cells correlates with the presence of focal adhesion kinase phosphorylated at tyrosines 397 and 407

Gastrin-releasing peptide (GRP) and its receptor (GRP-R) are not normally expressed by epithelial cells lining the colon but are aberrantly expressed in cancer, where they act as morphogens and regulate tumor cell differentiation. Studies of colon cancer formation in mice genetically incapable of synthesizing GRP-R suggested that this receptor's morphogenic properties were mediated via focal adhesion kinase (FAK). We therefore set out to determine the presence of both total and phosphorylated forms of FAK in human colon cancer specimens as a function of tumor cell differentiation and GRP/GRP-R co-expression. Ten colon cancers containing 25 regions of distinct differentiation were randomly selected from our GI Cancer Tumor Bank. All specimens were immunohistochemically probed using antibodies recognizing GRP, GRP-R, total FAK, and FAK specifically phosphorylated at tyrosine (Y) 397, 407, 576, 577, 861, and 925. Antibody-specific chromogen was determined by quantitative immunohistochemistry (IHC) for each region of defined differentiation. Here we confirm that GRP/GRP-R co-expression is a function of differentiation, with highest levels observed in well-differentiated tumor cells. We also show that the amount of total FAK and of FAK phosphorylated at Y397 and Y407 tightly correlates with differentiation and with the amount of GRP/GRP-R co-expression. These findings are consistent with GRP/GRP-R acting as a morphogen by activating FAK, and suggest that this occurs via phosphorylation of this enzyme at two specific tyrosine residues.

Increased frequency of gastrin-releasing peptide receptor gene mutations during colon-adenocarcinoma progression

Epithelial cells lining the mature human colon do not normally express receptors for gastrin-releasing peptide (GRPR). In contrast, we have shown that when aberrantly expressed in functional form in colon cancer, this protein acted as a morphogen where it caused tumor cells to adopt a better-differentiated phenotype. Importantly, GRPR mRNA is ubiquitously mutated in human colon cancer cell lines, with inactivating mutations detected in all cell lines not expressing functional receptor. Since colon cancers are heterogeneously differentiated, we set out to determine if the GRPR gene was mutated as a function of tumor cell differentiation in archived human colon cancers. We used laser capture microscopy to dissect out 67 regions of defined differentiation from 20 human colon cancers randomly selected from the UIC GI Tumor Bank. Except for two polymorphisms, the GRPR gene was not mutated in nonmalignant epithelial cells. In contrast, 42 distinct mutations were identified in malignant cells. Overall mutation number inversely correlated with the degree of tumor cell differentiation. Within any cancer, all GRPR mutations found within better-differentiated cells were conserved in more poorly-differentiated cells; while all poorly-differentiated cells contained mutations resulting in GRPR pharmacological inactivation. These data suggest that accumulation of mutations within the GRPR gene ultimately resulting in the production of nonfunctional receptors may represent a previously unappreciated mechanism allowing for the dedifferentiation of tumor cells within any particular colon cancer; and that poorly-differentiated tumor cells within any individual cancer may arise clonally from their better-differentiated precursors.

Elevated expression of valosin-containing protein (p97) in hepatocellular carcinoma is correlated with increased incidence of tumor recurrence

PURPOSE

Valosin-containing protein (VCP; also known as p97) has been shown to be associated with antiapoptotic function and metastasis via activation of the nuclear factor-kappaB signaling pathway. In this study, association of VCP expression with recurrence of hepatocellular carcinoma (HCC) and patient survival was examined.

PATIENTS AND METHODS

VCP expression in 170 patients (139 male and 31 female) with ages ranging from 31 to 81 years (median, 61 years) was analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry, in which staining intensity in tumor cells was categorized as weaker (level 1) or equal to or stronger (level 2) than that in endothelial cells.

RESULTS

Immunohistochemically, 57 patients (35.2%) showed level 1, and 105 patients (64.8%) showed level 2, VCP expression. Quantitative RT-PCR analysis revealed higher VCP mRNA expression in level 2 patients (n = 7) than level 1 (n = 4) (P <.05). Patients with VCP-level 2 HCC showed higher rate of portal vein invasion in the tumor (P <.01) and poorer disease-free and overall survival (P <.0001 and P <.05, respectively) compared with level 1 patients. Multivariate analysis revealed VCP expression level, tumor multiplicity, and degree of fibrosis in the noncancerous liver tissue to be independent prognosticators for disease-free and overall survival. VCP level was an indicator for disease-free survival in each early- (I and II) and advanced- (III and IV) stage group of pathologic tumor-node-metastasis classification (P <.001 and P <.01, respectively).

CONCLUSION

VCP expression level has prognostic significance for disease-free and overall survival of patients with HCC.

Prospective validation of the CLIP score: a new prognostic system for patients with cirrhosis and hepatocellular carcinoma. The Cancer of the Liver Italian Program (CLIP) Investigators

Prognosis of patients with cirrhosis and hepatocellular carcinoma (HCC) depends on both residual liver function and tumor extension. The CLIP score includes Child-Pugh stage, tumor morphology and extension, serum alfa-fetoprotein (AFP) levels, and portal vein thrombosis. We externally validated the CLIP score and compared its discriminatory ability and predictive power with that of the Okuda staging system in 196 patients with cirrhosis and HCC prospectively enrolled in a randomized trial. No significant associations were found between the CLIP score and the age, sex, and pattern of viral infection. There was a strong correlation between the CLIP score and the Okuda stage. As of June 1999, 150 patients (76.5%) had died. Median survival time was 11 months, overall, and it was 36, 22, 9, 7, and 3 months for CLIP categories 0, 1, 2, 3, and 4 to 6, respectively. In multivariate analysis, the CLIP score had additional explanatory power above that of the Okuda stage. This was true for both patients treated with locoregional therapy or not. A quantitative estimation of 2-year survival predictive power showed that the CLIP score explained 37% of survival variability, compared with 21% explained by Okuda stage. In conclusion, the CLIP score, compared with the Okuda staging system, gives more accurate prognostic information, is statistically more efficient, and has a greater survival predictive power. It could be useful in treatment planning by improving baseline prognostic evaluation of patients with HCC, and could be used in prospective therapeutic trials as a stratification variable, reducing the variability of results owing to patient selection.