Multicentric Hepatocarcinogenesis Research Articles

Abstract 3535: Identification of multiple hepatocellular carcinoma using genomic approach

Abstract Multiple hepatocellular carcinoma (HCC) is categorized into two types; multicentric hepatocarcinogenesis (MC) and intrahepatic metastasis (IM). Although clinical discrimination of the types of multiple HCC has been proposed, it is quite difficult to determine it correctly even after histological diagnosis. In order to diagnose multiple HCC as MC or IM, we compared pairs of multiple HCC samples from 60 patients with multiple HCC and 2 patients with pairs of primary HCC and extrahepatic metastasis such as adrenal grand and lung metastasis with regard to molecular aberrations. Exome or capture sequences showed that more than 70% of somatic mutations were common in the pairs of IM, which were consistent with the result of a pair of primary HCC and extrahepatic metastasis, while no common somatic mutations was detected in genomic MC pairs. Notably, more than 60% of patients who were clinically diagnosed metachronous MC were genetically IM due to the concordance of mutation and shows significantly frequent tumor thrombus, suggesting that genomic IM pairs developed from the common ancestor. Epigenetically, methylation profiles were similar in a pair of IM, while those of MC were different each other. Consequently the accuracy of clinical diagnosis of multiple HCC was only 53.3%. In addition, cell-free DNA was analyzed using exome sequence in five patients with recurrent HCC, and found that somatic mutations of cell free DNA were similar to the primary HCC only in genomic IM but not in genomic MC cases. Intriguingly, overall survivals of patients with clinical IM was significantly shorter than those with clinical MC, while overall survivals of patients with genomic IM and genomic MC were almost similar. Taken together, comparison of mutations in a pair of HCCs makes it possible to classify multiple HCC into MC and IM, which is difficult to be correctly determined in clinical practice. In addition our data showed that it is not clinically important to determine the types of multiple HCC. Furthermore liquid biopsy for mutation analysis is available to make treatment plans for multiple HCC patients. Citation Format: Yutaka Midorikawa, Shogo Yamamoto, Kenji Tatsuno, Hiroki Ueda, Tadatoshi Takayama, Hiroyuki Aburatani. Identification of multiple hepatocellular carcinoma using genomic approach [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3535.

Abstract 4392: Genetic diagnosis of multiple hepatocellular carcinoma

Abstract Multiple hepatocellular carcinoma (HCC) is categorized into two types; multicentric hepatocarcinogenesis (MC) and intrahepatic metastasis (IM). Although discrimination of the types of multiple HCC is of clinical importance, it is quite difficult to determine it correctly even after histological diagnosis. In order to determine multiple HCC as MC or IM, we compared pairs of multiple HCC samples from 40 patients with multiple HCC and 2 patients with pairs of primary HCC and extrahepatic metastasis such as adrenal grand and lung metastasis with regard to molecular aberrations. Exome sequence showed that more than 70% of somatic mutations were common in the pairs of IM, which were consistent with the result of a pair of primary HCC and extrahepatic metastasis, while no common somatic mutations was detected in genomic-MC (gMC) pairs. Notably, more than 60% of clinically metachronous-MC cases were diagnosed as genomic-IM (gIM) due to the concordance of mutation and shows significantly frequent tumor thrombus, suggesting that gIM pairs developed from the common ancestor. In addition, cell-free DNA was analyzed using exome sequence in five patients with recurrent HCC, and found that somatic mutations of cell free DNA were similar to the primary HCC only in gIM but not in gMC cases. Taken together, comparison of mutations in a pair of HCCs makes it possible to classify multiple HCCs into MC and IM, which is difficult to be correctly determined in clinical practice. Furthermore liquid biopsy for mutation analysis is available to make treatment plans for multiple HCC patients. Citation Format: Yutaka Midorikawa, Shogo Yamamoto, Kenji Tatsuno, Hiroki Ueda, Shingo Tsuji, Genta Nagae, Tadatoshi Takayama, Hiroyuki Aburatani. Genetic diagnosis of multiple hepatocellular carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4392. doi:10.1158/1538-7445.AM2017-4392

Abstract 163: Genetic difference between multicentric carcinogenesis and intrahepatic metastasis of hepatocellular carcinoma

Abstract Multiple hepatocellular carcinoma (HCC) is categorized into 2 types; multicentric hepatocarcinogenesis (MC) and intrahepatic metastasis (IM). Although discrimination of the types of multiple HCC is of clinical importance, it is quite difficult to determine it correctly even after histological diagnosis. In order to classify multiple HCC into MC and IM, we compared pairs of multiple HCC samples from 12 patients who were clinically diagnosed MC, 6 patients with IM with regard to molecular aberrations, and 2 patients with pairs of primary HCC and extrahepatic metastasis such as adrenal grand and lung metastasis. Exome sequence showed that 125 mutations (90.6%) per patient with IM were common, which were consistent with the result of a pair of primary HCC and extrahepatic metastasis. On the other hand, 138 somatic mutations per tumor, and no common somatic mutations were identified in the 7 patients with MC. Especially only a few passenger mutations were different between IM specimens suggesting that IM pairs developed from the common ancestor. In contrast, 5 patients who clinically diagnosed MC had common mutations (41.7%), which indicates that pairs of HCC of these patients were genetically IM. Notably, mutation signatures obtained from exome sequence data of 2 nodules from the same patients with IM were similar, while those from patients with MC were different by profiling analysis. On the other hand, methylation profile shows that 2 HCC samples from the same patients with MC as well as IM were classified into the same cluster; the methylation status from the different ancestor is similar, and not altered through carcinogenesis. Taken together, comparison of mutations in a pair of HCCs makes it possible to classify multiple HCCs into MC and IM, which is difficult to be correctly determined in clinical practice, and is available to make treatment plans for multiple HCC patients. Furthermore, methylation status of 2 nodules of MC from same patient were similar, while those of mutation signatures were different, which suggests that the epigenomic changes are the earlier event prior to the genomic alterations. Citation Format: Yutaka Midorikawa, Shogo Yamamoto, Kenji Tatsuno, Hiroki Ueda, Shingo Tsuji, Genta Nagae, Tadatoshi Takayama, Hiroyuki Aburatani. Genetic difference between multicentric carcinogenesis and intrahepatic metastasis of hepatocellular carcinoma. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 163.

Multicentric hepatocarcinogenesis at 6 and 13years after sustained viral response to hepatitis C virus.

A 68-year-old Japanese woman with chronic hepatitis C infection who achieved sustained viral response (SVR) was followed up regularly. Six years after SVR, alpha fetoprotein (AFP) was increased. Hepatocellular carcinoma (HCC) was diagnosed by computed tomography and was excised by hepatic resection. Thirteen years after SVR, AFP increased again, and HCC recurrence was detected, which was excised by hepatic resection. Each HCC was <2cm in diameter, with no vascular invasion. The primary HCC was moderately differentiated, while the secondary was well-to-moderately differentiated. Based on the clinicopathological features, the hepatocarcinogenesis was considered multicentric. Our case illustrates the importance of long-term follow-up of patients who achieve SVR.

Abstract 1989: Gene expression signature of the non-cancerous liver tissue associated with the early recurrence of hepatocellular carcinoma

Abstract Recurrence of hepatocellular carcinoma (HCC) might be associated with biological aggressiveness of the cancer as well as background status of the liver. In this study, the predictive values for the early recurrence were assessed on patients with HCC after curative hepatectomy using clinicopathological factors and genome-wide gene expression signatures. Multivariate analysis of clinico-pathological factors revealed portal vein invasion (p=0.007), hepatitis C virus infection (p=0.001), and low levels of serum albumin (p=0.003) as the risk factors, yielding a ROC-plot AUC value of 0.854 with 61.5% sensitivity and 81.8% specificity. Analysis of the gene expression profiling on the cancer tissues of HCC revealed the significant differences in CD24 stem cell marker and MTSS1 metastasis suppressor molecule. The cancer six-gene signature for the prediction of recurrence yielded a ROC-plot AUC value of 0.897 with 81.8% sensitivity and 88.5% specificity. Using the non-cancerous liver tissues surrounding HCC, distinct differences were recognized by the gene expression profiling such as IGL immunoglobulin lambda light chain and MAP2K1 mitogen-activated protein kinase kinase. The non-cancer six-gene signature yielded a ROC-plot AUC value of 0.966 with 84.8% sensitivity and 88.5% specificity for the prediction of HCC recurrence. These gene expression signatures can be involved in the metastatic potentials of the invasive HCC, and the multi-centric hepatocarcinogenesis, respectively. Our results might indicate the molecular targets for prediction and/or treatment of the recurrence, as well as the super-high risk group of HCC within the patients with hepatitis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1989.

Differentiating Early and Late Recurrences After Resection of HCC in Cirrhotic Patients: Implications on Surveillance, Prevention, and Treatment Strategies

Hepatocellular carcinoma (HCC) is one of the most common human malignancies. The majority of HCCs occur in a background of cirrhosis related to hepatitis B virus, hepatitis C virus, or alcoholism. The presence of cirrhosis has significant impact on the management of the cancer. The impairment of liver function as a result of cirrhosis restricts the treatment options, and cirrhosis is also known to predispose to multicentric hepatocarcinogenesis and increase the risk of recurrence after resection of HCC. The advent of liver transplantation and radiofrequency ablation have provided better chances of curative treatment for patients with small HCC detected by screening in recent years; however, hepatic resection remains the mainstay of curative treatment for HCC associated with Child-Pugh class A cirrhosis. While the perioperative safety and long-term survival of liver resection in cirrhotic liver have improved in recent years, the rate of postoperative recurrence of HCC remains high. In more than 80% of the cases of postoperative recurrence after resection of HCC, the recurrent tumors occur in the liver remnant. The mechanisms of intrahepatic recurrence can be either intrahepatic metastasis from the initial tumor or a de novo multicentric tumor. Differentiation of the two has potential implications on surveillance, prevention, and management strategies for recurrence. Clinically, it is impossible to distinguish the two based on imaging appearances. The only definitive way of differentiation is by genetic or molecular studies of the clonal origin of the tumors, which are technically complicated and cannot be used in clinical practice. Hence, several groups of authors have attempted to differentiate intrahepatic metastasis and multicentric recurrence based on the interval of development of recurrence from the time of resection and risk factors associated with the recurrence. These studies have consistently demonstrated that early recurrence within the first 2 years after resection of HCC is likely to be associated with aggressive tumor pathological factors such as high tumor grade, microvascular invasion, and microsatellite lesions, whereas late recurrence is more likely related to underlying liver conditions such as the presence of cirrhosis and hepatitis activity. Such results suggested that early recurrence is most likely the consequence of occult metastasis from the initial tumor, whereas late recurrence more likely represents multicentric tumors. Cucchetti et al. conducted a study on the risk factors associated with early and late recurrence in 204 patients with cirrhosis who had undergone resection of HCC. The authors identified high alpha-fetoprotein level, poorly differentiated tumor, and microvascular invasion as the risk factors for early recurrence within 2 years after resection, and male gender, older age, high transaminase levels, multiple primary tumors, and high alpha-fetoprotein level as risk factors for late recurrence beyond 2 years. These findings are generally in line with those of previous studies. To demonstrate that late recurrence is most likely related to new multicentric tumor development in the cirrhotic liver, the authors further compared the incidence and risk factors of late recurrence in resected patients with the those of development of HCC in a cohort of 150 cirrhotic patients undergoing regular surveillance of HCC. Such data are not available in previous studies and provide a better insight into the risk of late recurrence after resection of HCC in cirrhotic patients. The authors showed that the risk factors for development of HCC in a group of cirrhotic patients undergoing surveillance were similar to the risk Society of Surgical Oncology 2009

Hepatitis C virus core protein induces spontaneous and persistent activation of peroxisome proliferator‐activated receptor α in transgenic mice: Implications for HCV‐associated hepatocarcinogenesis

Persistent infection of hepatitis C virus (HCV) can lead to a high risk for hepatocellular carcinoma (HCC). HCV core protein plays important roles in HCV-related hepatocarcinogenesis, because mice carrying the core protein exhibit multicentric HCCs without hepatic inflammation and fibrosis. However, the precise mechanism of hepatocarcinogenesis in these transgenic mice remains unclear. To evaluate whether the core protein modulates hepatocyte proliferation and apoptosis in vivo, we examined these parameters in 9- and 22-month-old transgenic mice. Although the numbers of apoptotic hepatocytes and hepatic caspase 3 activities were similar between transgenic and nontransgenic mice, the numbers of proliferating hepatocytes and the levels of numerous proteins such as cyclin D1, cyclin-dependent kinase 4 and c-Myc, were markedly increased in an age-dependent manner in the transgenic mice. This increase was correlated with the activation of peroxisome proliferator-activated receptor alpha (PPARalpha). In these transgenic mice, spontaneous and persistent PPARalpha activation occurred heterogeneously, which was different from that observed in mice treated with clofibrate, a potent peroxisome proliferator. We further demonstrated that stabilization of PPARalpha through a possible interaction with HCV core protein and an increase in nonesterified fatty acids, which may serve as endogenous PPARalpha ligands, in hepatocyte nuclei contributed to the core protein-specific PPARalpha activation. In conclusion, these results offer the first suggestion that HCV core protein induces spontaneous, persistent, age-dependent and heterogeneous activation of PPARalpha in transgenic mice, which may contribute to the age-dependent and multicentric hepatocarcinogenesis mediated by the core protein.

Specific Gene-Expression Profiles of Noncancerous Liver Tissue Predict the Risk for Multicentric Occurrence of Hepatocellular Carcinoma in Hepatitis C Virus–Positive Patients

Hepatitis C virus (HCV) infection produces chronic hepatitis, cirrhosis, and, ultimately, hepatocellular carcinoma (HCC). A molecular analysis of the damaged liver tissues infected with HCV may identify specific gene-expression profiles associated with a risk for liver carcinogenesis. Forty patients with HCV-positive HCC were classified into two groups: single nodular HCC group (n = 28) and multicentric HCC group (n = 12). Using a complementary DNA microarray, we compared the gene-expression patterns of the noncancerous liver tissue specimens between the two groups. We also identified the differentially expressed genes related to multicentric recurrence in the liver remnant. We then evaluated whether a specific gene-expression profile can accurately estimate the risk for multicentric hepatocarcinogenesis. We selected the 230 differentially expressed genes in the multicentric HCC group. A hierarchical clustering analysis identified a cluster that might be closely associated with the multicentric occurrence of HCC. On the basis of the gene-expression profiling of the 36 genes commonly associated with both multicentric HCC and multicentric recurrence, we created a scoring system to estimate the risk for multicentric hepatocarcinogenesis. The prediction score of patients in the multicentric HCC group with multicentric recurrence (19.9 +/- 9.2) was significantly higher (P < .05) than that in the single nodular HCC group without multicentric recurrence (-1.8 +/- 12.7). Specific gene-expression signatures in noncancerous liver tissue may help to accurately predict the risk for developing HCC.

Prognostic Significance of Simultaneous Measurement of Three Tumor Markers in Patients With Hepatocellular Carcinoma

We conducted a prospective study to evaluate the significance of simultaneous measurement of 3 currently used tumor markers in the evaluation of tumor progression and prognosis of patients with hepatocellular carcinoma (HCC). Three tumor markers for HCC, alpha-fetoprotein (AFP), Lens culinaris agglutinin A-reactive fraction of AFP (AFP-L3), and des-gamma-carboxy prothrombin (DCP), were measured in the same serum samples obtained from 685 patients at the time of initial diagnosis of HCC. Positivity for AFP >20 ng/dL, AFP-L3 >10% of total AFP, and/or DCP >40 mAU/mL was determined. In addition, tumor markers were measured after treatment of HCC. Of the 685 patients, 337 (55.8%) were positive for AFP, 206 (34.1%) were positive for AFP-L3, and 371 (54.2%) were positive for DCP. In a comparison of patients positive for only 1 tumor marker, patients positive for AFP-L3 alone had a greater number of tumors, whereas patients positive for DCP alone had larger tumors and a higher prevalence of portal vein invasion. When patients were compared according to the number of tumor markers present, the number of markers present clearly reflected the extent of HCC and patient outcomes. The number of markers present significantly decreased after treatment. Tumor markers AFP-L3 and DCP appear to represent different features of tumor progression in patients with HCC. The number of tumor markers present could be useful for the evaluation of tumor progression, prediction of patient outcome, and treatment efficacy.

Interferon reduces somatic mutation of mitochondrial DNA in liver tissues from chronic viral hepatitis patients

We recently reported that the genetic instability resulting in the high rate of mitochondrial DNA (mtDNA) mutation in noncancerous liver tissue is consistent with the multicentric hepatocarcinogenesis detected clinically. Interferon (IFN) has been reported to reduce hepatocarcinogenesis in individuals with hepatitis virus infection. Liver biopsy specimens were obtained from 26 patients with chronic hepatitis C virus (HCV) infection before and after IFN therapy (total dose: 252 million units). The mean (+/-SD) age of the study population was 45 +/- 9 years and 13 (50%) were male [mode of acquisition: blood transfusion (27%), unknown (73%); viral load: 5.2 +/- 1.1 k copies/mL; duration of infection: 17 +/- 9 years (65%), unknown (35%); genotype: I (4%), II (80%), III (8%), IV (8%); alcohol intake: positive (31%), negative (69%)]. DNA samples were extracted from the specimens and subjected to direct sequencing. The mtDNA mutation frequency in the D-loop was increased in liver specimens from individuals with HCV infection compared with 21 controls (2.5 vs 0.6, P < 0.001). IFN therapy decreased the mtDNA mutation (mean difference = 0.7, P < 0.001) and the decreased number of mtDNA mutations was positively correlated with suppression of the total histological activity index score (mean difference = 1.3, P < 0.01). These results clearly indicate that the mutational rate of mtDNA is strongly associated with IFN therapy. Thus, analysis of mtDNA could provide a new criterion for the therapeutic evaluation of the effect of IFN, and may be useful for the prediction of risk of carcinogenesis.

Pathological Study on Multicentric Occurrence of Hepatocellular Carcinoma

Recently, it has been suggested that many of hepatocellular carcinoma (HCC) are of multicentric origin based on the clinicopathologic studies on small HCCs of the early stage and clinical follow-up studies after successful treatments of small HCCs. The author studied the multicentric occurrence of HCC from the point of view of pathomorphology in 168 HCCs less than 3 cm in diameter consecutively resected from 1999 to 2004 and 8 autopsy of liver cirrhosis of micronodular type from 1990 to 2004 at Kurume University Hospital from 1999 to 2004. The association of well-differentiated HCC ranging from 9 mm to 1.2 cm in diameter was found in the non-cancerous tissue of 9 cases (9.5%) among 94 cirrhotic livers. Adenomatous hyperplasia (AH) was found in 7 cases (7.4%). Accordingly, prevalence of synchronous and metachronous multicentric hepatocarcinogenesis was highly suggested in 9.5% and 7.4%, respectively. In 4 (50%) of the 8 autopsy cases of micronodular cirrhosis, however, the coexistence of 2 well-differentiated HCCs around 1.5 cm were found in the different segment. The prevalence of multicentric occurrence in the resected cases is the lowest estimation and true prevalence should be much more higher because HCC cases with multiple nodules are not sent to surgery and the observation is limited in a small area of the subsegmentectomized liver. Indeed, the result of autopsy cases reflects a true prevalence (50%) of synchronous occurrence of HCC.

Multicentric occurrence of hepatocellular carcinoma in patients with a somatic mutation of mitochondorial DNA and hepatitis C virus

The relationship between the multicentric occurrence of hepatocellular carcinoma (HCC) and the frequency of mutation of mitochondrial DNA (mtDNA) in the noncancerous hepatic tissue in patients infected with hepatitis C virus was investigated. Of the 48 patients, multicentric occurrence of HCC was found in ten of 33 patients with three or more mutations in the mtDNA, whereas no patients had multicentric HCCs in 15 patients with two or fewer mutations in the mtDNA ( P=0.0201). A high rate of mtDNA mutation in noncancerous hepatic tissue may be related to multicentric hepatocarcinogenesis and the hypercarcinogenic state in such patients.

Close association between high serum alanine aminotransferase levels and multicentric hepatocarcinogenesis in patients with hepatitis C virus-associated cirrhosis.

Multicentric development of hepatocellular carcinoma (HCC) is a characteristic feature of hepatitis C virus (HCV)-associated cirrhosis (HCV-LC). In this study, the objective was to determine whether the persistent elevation of the serum alanine aminotransferase (ALT) level, which represents the inflammatory necrosis of hepatocytes, is correlated with the multicentric development of hepatocellular carcinoma (HCC) in patients with early-stage HCV-LC. Ninety-three consecutive patients with biopsy proven HCV-LC (Child Stage A) who had been followed for > 5 years for the development of HCC were studied. They were subdivided into three groups according to their serum ALT level: Group A included 33 patients with annual average serum ALT levels that were persistently high (> or = 80 IU; high ALT group), Group B included 41 patients with annual average serum ALT levels that were persistently low (< 80 IU; low ALT group), and Group C included 19 unclassified patients. The patients had been studied prospectively with frequent ultrasonography and magnetic resonance imaging or computed tomography (CT) scans for > 5 years. When the development of HCC was suspected, angiography, infusion of lipiodol into the hepatic artery, and lipiodol-CT scans were performed in all patients to determine the number of HCC nodules. In Group A, 27 patients (81.8%) developed HCC. Seventeen of 27 patients (63.0%) had multiple nodules. In contrast, in Group B, only 12 patients (29.3%) developed HCC, and only 1 of these 12 patients (8.3%) had multiple nodules. There was a significant difference between Groups A and B in the incidence of developing HCC (P < 0.001) and developing multiple nodules (P = 0.006). In addition, among the male patients, the incidence of developing multiple HCC nodules in Group A (12 of 19 patients; 63.2%) was significantly higher (P < 0.05) compared with the incidence in Group B (0 of 6 patients; 0%). The same tendency was observed among the female patients. These results showed a close correlation between multicentric hepatocarcinogenesis and sustained necroinflammation of the liver in patients with HCV-LC.

Clinicopathologic risk factors for recurrence after a curative hepatic resection for hepatocellular carcinoma

The long-term prognosis after resection for patients with hepatocellular carcinoma is still unsatisfactory because of the high recurrence rate. The survival of patients with multiple intrahepatic or extrahepatic recurrence is especially poor. Among the patients who underwent hepatic resection for hepatocellular carcinoma between 1981 and 2000, 216 patients with 3 or less than 3 intrahepatic recurrences (group B); 156 patients with more than 3 intrahepatic recurrences, extrahepatic recurrences, or both (group C); and 51 patients who survived more than 5 years without recurrence (group A) were clinicopathologically studied. The period to recurrence of group C was significantly earlier than that of group B and also showed a significantly poor prognosis after recurrence. Tumor factors, including size, portal venous invasion, intrahepatic metastasis, histologic grade, or the number of tumors at resection in group C was significantly worse than in groups A and B. Although no differences are recognized in the tumor factors between groups A and B, except for the alpha-fetoprotein level, liver function in group B was significantly worse than that in group A. In addition, the frequency of hepatitis B surface antigen in group B and that of hepatitis C virus in group B was significantly less and higher than that in group A, respectively. Similar to extrahepatic metastasis, multinodular recurrences are also mainly caused by metastatic recurrence from the main tumor by means of the portal system, and recurrences with up to 3 intrahepatic nodules are mainly caused by metachronous multicentric hepatocarcinogenesis. Because the mechanisms of recurrence differed, determining the patterns of recurrence on the basis of the clinicopathologic findings is important for selecting the optimal postoperative therapy for each individual patient.

Repeat hepatectomy is the most useful treatment for recurrent hepatocellular carcinoma.

Hepatic resection has been regarded as a curative treatment for primary hepatocellular carcinoma (HCC), but a high incidence of postoperative recurrence is general. Thus it is important to predict the patterns of recurrence and select the appropriate treatment for recurrence for a better long-term prognosis of patients with HCC. Clinicopathological studies on 80 patients with intrahepatic recurrence after curative hepatectomy suggested that nodular-type recurrence with up to three nodules is mainly due to metachronous multicentric hepatocarcinogenesis rather than intrahepatic metastases. We reviewed 300 patients with recurrent HCC, and repeat hepatectomy was done in 78 cases (26.0%). The 3- and 5-year survival rates after repeat hepatectomy were 82.8% and 47.5%, respectively, showing better prognosis than those for other treatments. Repeat hepatectomy is the preferred treatment offering a hope of long-term survival for patients with recurrent HCC as long as liver function is sufficient; thus early detection of recurrence should be ensured.

Hyperplastic foci reflect the risk of multicentric development of human hepatocellular carcinoma

Background/Aims: Identification of the risk factors of multicentric hepatocarcinogenesis is important for the clinical management of hepatocellular carcinoma. We investigated hyperplastic foci in non-cancerous liver parenchyma, and clarified their pathological features and clinical significance. Methods: Hyperplastic foci were defined as hypercellular areas, which architecturally and cytologically resembled early hepatocellular carcinoma or adenomatous hyperplasia but did not form macroscopically detectable nodules. Surgically resected livers from 155 patients with hepatocellular carcinoma were examined histopathologically and immunohistochemically. Results: Hyperplastic foci were found in 26 of 155 patients (16.8%). All the patients with hyperplastic foci had chronic liver diseases, and the incidence did not differ between those with chronic hepatitis and those with liver cirrhosis. Six of 92 (6.5%) patients with single primary hepatocellular carcinoma nodules, 8 of 42 (19.0%) with two nodules, and 12 of 21 (57.0%) with more than three nodules had hyperplastic foci. The incidence of hyperplastic foci showed a significant positive correlation with the multiplicity of hepatocellular carcinoma nodules. Immunohistochemically, hyperplastic foci were masses of proliferative hepatocytes similar to adenomatous hyperplasia and early hepatocellular carcinoma. Conclusions: Hyperplastic foci reflect the risk of multicentric hepatocarcinogenesis. Our results suggest strongly that hyperplastic foci are precursors of adenomatous hyperplasia or hepatocellular carcinoma.

Clinicopathological criteria for multicentricity of hepatocellular carcinoma and risk factors for such carcinogenesis.

Multicentric occurrence is an important characteristic of hepatocellular carcinoma. We evaluated clinicopathological criteria for multicentric hepatocellular carcinoma and identified risk factors for such carcinogenesis. Subjects were 251 consecutive patients undergoing liver resection for hepatocellular carcinoma. One kind of multicentric hepatocellular carcinoma had at least one tumor consisting of well‐differentiated hepatocellular carcinoma, together with moderately or poorly differentiated hepatocellular carcinoma located in a separate region. The other kind had an area of well‐differentiated component around hepatocellular carcinoma with less differentiation in all occurrences. The outcome of patients with tumors classified in this way was studied. Univariate and multivariate analyses were done to identify risk factors for multicentric hepatocellular carcinoma. The cumulative survival rate was significantly higher in patients with multicentric hepatocellular carcinoma than in patients with hepatocellular carcinoma associated with intrahepatic metastasis. Analysis by Cox's proportional hazard model showed that multicentricity was not a factor in the outcome. The risk of multicentric occurrence increases with progression of chronic liver disease. Univariate analysis showed hepatitis C virus marker and hepatitis B core antibody to be risk factors. By multivariate analysis, the odds ratio for multicentric occurrence in patients infected with hepatitis C virus and with serum hepatitis B virus core antibody compared with patients without either hepatitis C virus or hepatitis B virus was 10.86. This ratio in patients with hepatitis C virus alone was 4.30. These criteria for multicentric hepatocellular carcinoma seem to be clinically useful. Hepatitis C virus infection with or without former infection by hepatitis B virus is a strong risk factor for multicentric hepatocarcinogenesis.

Significant influence of accompanying chronic hepatitis status on recurrence of hepatocellular carcinoma after hepatectomy. Result of multivariate analysis.

The aim of this study was to evaluate the correlation between the histologic status of accompanying chronic hepatitis and the recurrence rate of hepatocellular carcinoma (HCC) after hepatectomy by multivariate analysis. Recent studies have suggested that a considerable number of intrahepatic recurrence of HCC after hepatectomy might be the results of metachronous multicentric hepatocarcinogenesis. The authors hypothesized that the incidence of recurrence due to metachronous multicentric hepatocarcinogenesis would depend on the histologic status of accompanying chronic viral liver disease, which is a main promoter of HCC. One hundred ten patients with HCC who underwent curative resection were studied. Histologic status of accompanying chronic hepatitis was classified into the three categories: 1) normal liver or chronic persistent hepatitis (CPH, n = 13), 2) chronic aggressive hepatitis (CAH, n = 50), and 3) liver cirrhosis (LC, n = 47). The Cox multivariate proportional hazard model showed that the accompanying chronic viral hepatitis status (p = 0.0133), extent of hepatectomy (p = 0.0078), and number of tumors (p = 0.0475) were significantly predictive variables for recurrence-free survival. By the log-rank test, recurrence-free survival rate in patients with CPH was significantly higher than those in patients with CAH (p = 0.0005) and LC (p = 0.0075). Patients with CAH had the lowest recurrence-free survival rate (vs. LC, p = 0.028). The results of this study indicated the significant influence of histologic activity of hepatitis on recurrence of HCC. This might support the concept of significant contribution of multicentric hepatocarcinogenesis to recurrence of HCC after hepatectomy.

Role of Increased DNA Synthesis Activity of Hepatocytes in Multicentric Hepatocarcinogenesis in Residual Liver of Hepatectomized Cirrhotic Patients with Hepatocellular Carcinoma

To examine whether the marked increase in DNA synthesis of hepatocytes in cirrhotic liver might elicit multicentric hepatocarcinogenesis, we examined the relationship between new development of hepatocellular carcinoma (HCC) and the bromodeoxyuridine (BrdU) labeling index (LI) of hepatocytes in the residual liver of hepatectomized patients with liver cirrhosis (LC) and HCC, Eighteen hepatectomized patients with LC and HCC, whose resected liver revealed neither portal nor hepatic vein invasion by histologic examination, were studied (to exclude cases with intrahepatic metastasis). DNA synthesis activity of hepatocytes from the residual cirrhotic liver was measured by a BrdU/ anti‐BrdU in vitro method. The incidence of HCC recurrence was studied during a 3‐year follow‐up period. Among 18 patients, 9 patients had recurrence and 9 did not. The average BrdU LI in the recurrent patients was 2.6 ±1.3% and was significantly higher than that in patients without recurrence (1.4+0.5%, P<0.05). All five patients who had a BrdU LI of 2.4% or above showed recurrence within 3 years, as compared with 4 of 13 (30.8%) patients with BrdU LI of less than 2.4% (P 0.05). Our data indicate that abnormally high DNA synthesis in hepatocytes in the background cirrhosis might lead to the development of multicentric carcinogenesis in human cirrhotic liver, and in the residual cirrhotic liver of hepatectomized patients with HCC and LC, it may be a predictor of new development of HCC.