Importance of field cancerisation in clinical oncology

AI-powered prediction of HCC recurrence after surgical resection: Personalised intervention opportunities using patient-specific risk factors

BACKGROUND

Hepatocellular carcinoma (HCC) recurrence following surgical resection remains a significant clinical challenge, necessitating reliable predictive models to guide personalised interventions. In this study, we sought to harness the power of artificial intelligence (AI) to develop a robust predictive model for HCC recurrence using comprehensive clinical datasets.

METHODS

Leveraging data from 958 patients across multiple centres in Australia and Hong Kong, we employed a multilayer perceptron (MLP) as the optimal classifier for model generation.

RESULTS

Through rigorous internal cross-validation, including a cohort from the Chinese University of Hong Kong (CUHK), our AI model successfully identified specific pre-surgical risk factors associated with HCC recurrence. These factors encompassed hepatic synthetic function, liver disease aetiology, ethnicity and modifiable metabolic risk factors, collectively contributing to the predictive synergy of our model. Notably, our model exhibited high accuracy during cross-validation (.857 ± .023) and testing on the CUHK cohort (.835), with a notable degree of confidence in predicting HCC recurrence within accurately classified patient cohorts. To facilitate clinical application, we developed an online AI digital tool capable of real-time prediction of HCC recurrence risk, demonstrating acceptable accuracy at the individual patient level.

CONCLUSION

Our findings underscore the potential of AI-driven predictive models in facilitating personalised risk stratification and targeted interventions to mitigate HCC recurrence by identifying modifiable risk factors unique to each patient. This model aims to aid clinicians in devising strategies to disrupt the underlying carcinogenic network driving recurrence.

Endoscopic follow-up of low-grade precancerous bronchial lesions in high-risk patients: long-term results of the SELEPREBB randomised multicentre trial

BACKGROUND

3-9% of low-grade preinvasive bronchial lesions progress to cancer. This study assessed the usefulness of an intensive bronchoscopy surveillance strategy in patients with bronchial lesions up to moderate squamous dysplasia.

METHODS

SELEPREBB (ClinicalTrials.gov NCT00213603) was a randomised study conducted in 17 French centres. After baseline lung computed tomography (CT) and autofluorescence bronchoscopy (AFB) to exclude lung cancer and bronchial severe squamous dysplasia or carcinoma in situ (CIS), patients were assigned to standard surveillance (arm A) with CT and AFB at 36 months or to intensive surveillance (arm B) with AFB every 6 months. Further long-term data were obtained with a median follow-up of 4.7 years.

RESULTS

364 patients were randomised (A: 180, B: 184). 27 patients developed invasive lung cancer and two developed persistent CIS during the study, with no difference between arms (OR 0.63, 95% CI 0.20-1.96, p=0.42). Mild or moderate dysplasia at baseline bronchoscopy was a significant lung cancer risk factor both at 3 years (8 of 74 patients, OR 6.9, 95% CI 2.5-18.9, p<0.001) and at maximum follow-up (16 of 74 patients, OR 5.9, 95% CI 2.9-12.0, p<0.001). Smoking cessation was significantly associated with clearance of bronchial dysplasia on follow-up (OR 0.12, 95% CI 0.01-0.66, p=0.005) and with a reduced risk of lung cancer at 5 years (OR 0.15, 95% CI 0.003-0.99, p=0.04).

CONCLUSION

Patients with mild or moderate dysplasia are at very high risk for lung cancer at 5 years, with smoking cessation significantly reducing the risk. Whereas intensive bronchoscopy surveillance does not improve patient outcomes, the identification of bronchial dysplasia using initial bronchoscopy maybe useful for risk stratification strategies in lung cancer screening programmes.

Hepatectomy for hepatocellular carcinoma with portal vein tumor thrombus

Despite surgical removal of tumors with portal vein tumor thrombus (PVTT) in hepatocellular carcinoma (HCC) patients, early recurrence tends to occur, and overall survival (OS) periods remain extremely short. The role that hepatectomy may play in long-term survival for HCC with PVTT has not been established. The operative mortality of hepatectomy for HCC with PVTT has also not been reviewed. Hence, we reviewed recent literature to assess these parameters. The OS of patients who received hepatectomy in conjunction with multidisciplinary treatment tended to be superior to that of patients who did not. Multidisciplinary treatments included the following: preoperative radiotherapy on PVTT; preoperative transarterial chemoembolization (TACE); subcutaneous administration of interferon-alpha (IFN-α) and intra-arterial infusion of 5-fluorouracil (5-FU) with infusion chemotherapy in the affected hepatic artery; cisplatin, doxorubicin and 5-FU locally administered in the portal vein; and subcutaneous injection of IFN-α, adjuvant chemotherapy (5-FU + Adriamycin) administration via the portal vein with postoperative TACE, percutaneous isolated hepatic perfusion and hepatic artery infusion and/or portal vein chemotherapy. The highest reported rate of operative mortality was 9.3%. In conclusion, hepatectomy for patients affected by HCC with PVTT is safe, has low mortality and might prolong survival in conjunction with multidisciplinary treatment.

Tumor-adjacent tissue co-expression profile analysis reveals pro-oncogenic ribosomal gene signature for prognosis of resectable hepatocellular carcinoma

Currently, molecular markers are not used when determining the prognosis and treatment strategy for patients with hepatocellular carcinoma (HCC). In the present study, we proposed that the identification of common pro‐oncogenic pathways in primary tumors (PT) and adjacent non‐malignant tissues (AT) typically used to predict HCC patient risks may result in HCC biomarker discovery. We examined the genome‐wide mRNA expression profiles of paired PT and AT samples from 321 HCC patients. The workflow integrated differentially expressed gene selection, gene ontology enrichment, computational classification, survival predictions, image analysis and experimental validation methods. We developed a 24‐ribosomal gene‐based HCC classifier (RGC), which is prognostically significant in both PT and AT. The RGC gene overexpression in PT was associated with a poor prognosis in the training (hazard ratio = 8.2, P = 9.4 × 10⁻⁶) and cross‐cohort validation (hazard ratio = 2.63, P = 0.004) datasets. The multivariate survival analysis demonstrated the significant and independent prognostic value of the RGC. The RGC displayed a significant prognostic value in AT of the training (hazard ratio = 5.0, P = 0.03) and cross‐validation (hazard ratio = 1.9, P = 0.03) HCC groups, confirming the accuracy and robustness of the RGC. Our experimental and bioinformatics analyses suggested a key role for c‐MYC in the pro‐oncogenic pattern of ribosomal biogenesis co‐regulation in PT and AT. Microarray, quantitative RT‐PCR and quantitative immunohistochemical studies of the PT showed that DKK1 in PT is the perspective biomarker for poor HCC outcomes. The common co‐transcriptional pattern of ribosome biogenesis genes in PT and AT from HCC patients suggests a new scalable prognostic system, as supported by the model of tumor‐like metabolic redirection/assimilation in non‐malignant AT. The RGC, comprising 24 ribosomal genes, is introduced as a robust and reproducible prognostic model for stratifying HCC patient risks. The adjacent non‐malignant liver tissue alone, or in combination with HCC tissue biopsy, could be an important target for developing predictive and monitoring strategies, as well as evidence‐based therapeutic interventions, that aim to reduce the risk of post‐surgery relapse in HCC patients.

Reformed smokers have survival benefits after head and neck cancer

Smoking tobacco is the main risk factor for head and neck cancer, is proportional to the number of pack years (number of packs smoked/day x number of years of smoking), and is reduced when the patient stops smoking. Current molecular evidence has suggested that tobacco-related cancers could be clinically more aggressive than cancers in non-smokers, particularly in the head and neck. However, clinical studies have not uniformly reproduced the relation between survival and tobacco, possibly because they ignore the health benefit that reformed smokers obtain during the period between giving up smoking and the diagnosis of cancer, which is not shared by those who continue to smoke and develop cancer. We have investigated the survival of reformed smokers, non-smokers, and continuing smokers after a diagnosis of head and neck cancer. The data of patients with head and neck cancer from 1992 -2013 from the Cancer Genome Atlas database were analysed using a multivariate Cox's regression model for survival, and Kaplan-Meier curves were produced for smoking history. A total of 521 patients were treated for head and neck cancer, and there was a significant difference in survival between reformed and non-smokers on the one hand, and current smokers on the other (p=0.02). The significance increased when reformed smokers were grouped according to their duration of abstinence and time of diagnosis of cancer (>15 and ≤15 years, p<0.01). Smoking history was a significant prognostic factor in the multivariate Cox's regression model when analysed with age, stage, grade, and site. We conclude that reformed smokers have a survival benefit in head and neck cancer.

Infiltrating hepatocellular carcinoma: seeing the tree through the forest

INTRODUCTION

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death worldwide. It is traditionally difficult to cure, especially when discovered at later stages, making early diagnosis and intervention of paramount importance. HCC typically arises in the background of chronic liver disease and can have various morphologic appearances. One of the most difficult of these to recognize on early surveillance imaging is the infiltrative subtype, which can account for up to 13% of all HCC cases, and may be more closely associated with background hepatitis B infection.

DISCUSSION

Certain imaging characteristics can provide vital clues, including differing signal intensity on the T1 and T2 sequences of magnetic resonance imaging (MRI) and the presence/appearance of portal vein thrombus. Owing to the diffuse and infiltrating properties of this tumor, surgical resection and transplantation are rarely if ever viable therapeutic options. Other forms of liver-directed therapy have been attempted with limited success, having minimal efficacy and high morbidity. To date, there is no data available to determine if the various HCC subtypes respond to systemic therapy differently, so this may be the most reasonable approach. Left untreated, observed patients commonly progress to hepatic failure fairly rapidly.

CONCLUSION

Infiltrative HCC can be extremely subtle, and therefore difficult to detect, especially in the background of cirrhosis. Providers caring for patients with hepatitis, chronic liver disease, and cirrhosis must be extremely vigilant in the evaluation of surveillance imaging in order to potentially discover this HCC subtype as early as possible and initiate a multidisciplinary treatment plan.

Deficient Pms2, ERCC1, Ku86, CcOI in field defects during progression to colon cancer

In carcinogenesis, the "field defect" is recognized clinically because of the high propensity of survivors of certain cancers to develop other malignancies of the same tissue type, often in a nearby location. Such field defects have been indicated in colon cancer. The molecular abnormalities that are responsible for a field defect in the colon should be detectable at high frequency in the histologically normal tissue surrounding a colonic adenocarcinoma or surrounding an adenoma with advanced neoplasia (well on the way to a colon cancer), but at low frequency in the colonic mucosa from patients without colonic neoplasia.

Using immunohistochemistry, entire crypts within 10 cm on each side of colonic adenocarcinomas or advanced colonic neoplasias were found to be frequently reduced or absent in expression for two DNA repair proteins, Pms2 and/or ERCC1. Pms2 is a dual role protein, active in DNA mismatch repair as well as needed in apoptosis of cells with excess DNA damage. ERCC1 is active in DNA nucleotide excision repair. The reduced or absent expression of both ERCC1 and Pms2 would create cells with both increased ability to survive (apoptosis resistance) and increased level of mutability. The reduced or absent expression of both ERCC1 and Pms2 is likely an early step in progression to colon cancer.

DNA repair gene Ku86 (active in DNA non-homologous end joining) and Cytochrome c Oxidase Subunit I (involved in apoptosis) had each been reported to be decreased in expression in mucosal areas close to colon cancers. However, immunohistochemical evaluation of their levels of expression showed only low to modest frequencies of crypts to be deficient in their expression in a field defect surrounding colon cancer or surrounding advanced colonic neoplasia.

We show, here, our method of evaluation of crypts for expression of ERCC1, Pms2, Ku86 and CcOI. We show that frequency of entire crypts deficient for Pms2 and ERCC1 is often as great as 70% to 95% in 20 cm long areas surrounding a colonic neoplasia, while frequency of crypts deficient in Ku86 has a median value of 2% and frequency of crypts deficient in CcOI has a median value of 16% in these areas. The entire colon is 150 cm long (about 5 feet) and has about 10 million crypts in its mucosal layer. The defect in Pms2 and ERCC1 surrounding a colon cancer thus may include 1 million crypts. It is from a defective crypt that colon cancer arises.

Molecular signatures of noncancerous liver tissue can predict the risk for late recurrence of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an aggressive malignancy mainly due to tumor metastases or recurrence even after undergoing potentially curative treatment. There are two types of HCC recurrence. The early and late tumor recurrences appear in distinct biological contexts, and their clinical courses are quite different. Therefore, it is important to precisely and distinctly discriminate the risk of each type of HCC recurrence. Many researchers have used DNA microarray technology to reclassify HCC with respect to its malignant potential. Some of these studies successfully identified specific gene-expression signatures derived from the cancerous tissues of HCC for predicting the early recurrence due to intrahepatic metastasis. However, there are no well-defined predictors for late recurrence. Recently, a few studies have focused on the nontumorous portion of liver tissues to predict late recurrence, possibly due to de novo hepatocarcinogenesis based on the idea of "field cancerization." This study reviewed the possible value of a gene-expression analysis of noncancerous liver tissue to clarify the risk for multicentric late recurrence of HCC. These findings may have important implications for chemopreventive strategies and tailored surveillance programs. Furthermore, this approach may also be applicable to other multifocal tumors, such as head and neck carcinoma.

Prognostic value and clinical relevance of the 6th Edition 2002 American Joint Committee on Cancer staging system in patients with resectable hepatocellular carcinoma

BACKGROUND

A simplified American Joint Committee on Cancer (AJCC) TNM staging system for hepatocellular carcinoma (HCC) (the 6th edition) was proposed in 2002. In this study, we validated the prognostic value of the staging system in a patient cohort undergoing hepatic resection with longterm followup.

STUDY DESIGN

From a prospective database, the study cohort consisted of 440 patients who underwent curative hepatic resection for HCC between July 1991 and January 1999. Median followup time was 66 months. Multivariate analysis was performed to identify the independent prognostic factors related to postoperative survival. Patients were staged according to both the 5th edition (TNM-5) and 6th edition (TNM-6) AJCC TNM staging criteria.

RESULTS

The independent prognostic factors included major vascular invasion, microvascular invasion, surgical margin < 1 cm, indocyanine green retention rate at 15 minutes > 10%, multiple tumors, tumor rupture, male, and serum aspartate aminotransferase > 90 U/L. The breakdown by TNM-5 staging: I, 27 (6.1%); II, 108 (24.5%); III, 218 (49.5%); and IVA, 87 (19.8%) and by TNM-6 staging: I, 120 (27.3%); II, 170 (38.6%); and III, 150 (34.1%). When stratified according to the TNM-5 system, difference in survival was notable between stages II and IIIA (p < 0.001), between stages IIIA and IVA (p < 0.001), but not between stages I and II (p > 0.05). When stratified according to the TNM-6 system, difference in survival was considerable between stages I and II (p < 0.01), stages II and III (p < 0.001), and stages I and III (p < 0.001).

CONCLUSIONS

Overall, the TNM-6 staging system appears to provide a reliable prognostic classification of HCC patients and is simpler to use than the TNM-5 staging system.

Surveillance for the detection of early lung cancer in patients with bronchial dysplasia

BACKGROUND

The natural history of bronchial preinvasive lesions and the risk of developing lung cancer in patients with these lesions are not clear. Previous studies have treated severe dysplasia and carcinoma in situ (CIS) on the assumption that most will progress to invasive carcinoma.

AIMS

To define the natural history of preinvasive lesions and assess lung cancer risk in patients with these lesions.

HYPOTHESIS

Most preinvasive lesions will not progress to invasive carcinoma but patients with these lesions will be at high risk.

METHODS

A cohort of patients with preinvasive lesions underwent fluorescence bronchoscopy every 4-12 months and computed tomography of the chest annually. The main end point was the development of invasive carcinoma.

RESULTS

22 patients with 53 lesions were followed up for 12-85 months. 11 cancers were diagnosed in 9 patients. Of the 36 high-grade lesions (severe dysplasia and CIS), 6 progressed to invasive cancers. 5 separate cancers developed at remote sites in patients with high-grade lesions. All cancers were N0M0 and curative treatment was given to 8 of the 9 patients. The cumulative risk of developing lung cancer in a patient with a high-grade lesion was 33% and 54% at 1 and 2 years, respectively. Of the 17 low-grade lesions, none progressed to invasive carcinoma.

CONCLUSIONS

Although the risk of malignant progression of individual preinvasive lesions is relatively small, patients with high-grade lesions are at high risk of lung cancer. Surveillance facilitated early detection and treatment with curative intent in most patients.

Specific gene-expression profiles of noncancerous liver tissue predict the risk for multicentric occurrence of hepatocellular carcinoma in hepatitis C virus-positive patients

BACKGROUND

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

Specific gene-expression signatures in noncancerous liver tissue may help to accurately predict the risk for developing HCC.

Hepatectomy for hepatocellular carcinoma with major portal or hepatic vein invasion: results of a multicenter study

BACKGROUND

The role of hepatic resection in patients with hepatocellular carcinoma (HCC) and invasion of a main portal or hepatic vein branch is controversial. We evaluated the efficacy of hepatic resection and the factors affecting survival after resection in such patients.

METHODS

The records of 102 patients who underwent resection for HCC with major vascular invasion between 1984 and 1999 were reviewed. Prognostic factors were evaluated by univariate and multivariate analysis.

RESULTS

The study included 87 men and 15 women. The median age was 59 years. The perioperative mortality rate was 5.9%. Median survival was 11 months (median follow-up, 93 months). The 1-, 3-, and 5-year survival rates were 45%, 17%, and 10%; the longest-living survivor was still alive at 14.8 years. Absence of moderate to severe fibrosis and absence of high nuclear grade were associated with a better 5-year survival rate (23% vs 5%; P = .001 and 21% vs 9%; P = .04, respectively). On multivariate analysis, moderate to severe fibrosis remained a significant predictor of both short-term (< or = 6 months) and long-term (>6 months) survival ( P < .03 and P < .01, respectively).

CONCLUSIONS

Hepatic resection for HCC with major vascular invasion is associated with median survival exceeding historical survival in patients not treated surgically. Patients with HCC and major vascular invasion who derive long-term benefit from resection have no or minimal underlying fibrosis.

Hepatitis serology predicts tumor and liver-disease characteristics but not prognosis after resection of hepatocellular carcinoma

The impact of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection on survival rates after resection of hepatocellular carcinoma (HCC) is controversial. The objective of this study was to determine whether serologic evidence of HBV or HCV infection ("hepatitis serology") can predict underlying liver disease, tumor factors, and survival rates in patients with HCC. Using a multicenter international database, we identified 446 patients with complete HBV and HCV serology. One hundred twenty-six patients were negative for HBV and HCV, 163 patients had HBV infection only, 79 patients had HCV infection only, and 78 patients had coinfection with HBV and HCV. Patients with hepatitis were more likely to have tumors smaller than 5 cm and bilateral HCC involvement. Hepatitis status (negative vs. HBV vs. HCV vs. coinfection with HBV and HCV) did not predict tumor grade or the presence of multiple tumor nodules. Patients with HCV or coinfection with HBV and HCV exhibited a lower incidence of vascular invasion, but worse fibrosis than patients with negative serology or HBV. The median survival rate was 47.9 months. The presence of hepatitis did not significantly affect the survival rate, but hepatic fibrosis and vascular invasion predicted a decreased survival rate. The prognosis after resection of HCC is influenced by tumor factors and liver disease, but not by HBV or HCV infection. The treatment for HCC should be dictated by the extent of underlying liver disease rather than by hepatitis serology.

Surgical treatment of hepatocellular carcinoma: similar long-term results despite geographic variations

Recently, the International Cooperative Study Group for hepatocellular carcinoma (HCC) proposed a new staging based on data from multiple centers across the world. The new TNM staging has been shown to be more accurate in the prognostic classification of patients after resection for HCC. This staging is the basis for the new TNM for HCC approved by the AJCC (American Joint Committee on Cancer) and UICC (Union Internationale Contre le Cancer). Although the general applicability of the new staging system has been confirmed, there still remains a marked geographic variation in the clinicopathologic factors of HCC patients based on their country of origin. Tumor size, rates of hepatitis, and degree of underlying liver damage all vary significantly among countries. Despite these geographic variations, recent data reveal similar long-term survival in Western and Eastern centers when these clinicopathologic factors are accounted for. Uniform criteria that account for these clinicopathologic differences need to be developed to assist in stratifying patients across hepatobiliary centers.

Cancer-associated molecular signature in the tissue samples of patients with cirrhosis

Several types of aggressive cancers, including hepatocellular carcinoma (HCC), often arise as a multifocal primary tumor. This suggests a high rate of premalignant changes in noncancerous tissue before the formation of a solitary tumor. Examination of the messenger RNA expression profiles of tissue samples derived from patients with cirrhosis of various etiologies by complementary DNA (cDNA) microarray indicated that they can be grossly separated into two main groups. One group included hepatitis B and C virus infections, hemochromatosis, and Wilson's disease. The other group contained mainly alcoholic liver disease, autoimmune hepatitis, and primary biliary cirrhosis. Analysis of these two groups by the cross-validated leave-one-out machine-learning algorithms revealed a molecular signature containing 556 discriminative genes (P <.001). It is noteworthy that 273 genes in this signature (49%) were also significantly altered in HCC (P <.001). Many genes were previously known to be related to HCC. The 273-gene signature was validated as cancer-associated genes by matching this set to additional independent tumor tissue samples from 163 patients with HCC, 56 patients with lung carcinoma, and 38 patients with breast carcinoma. From this signature, 30 genes were altered most significantly in tissue samples from high-risk individuals with cirrhosis and from patients with HCC. Among them, 12 genes encoded secretory proteins found in sera. In conclusion, we identified a unique gene signature in the tissue samples of patients with cirrhosis, which may be used as candidate markers for diagnosing the early onset of HCC in high-risk populations and may guide new strategies for chemoprevention. Supplementary material for this article can be found on the HEPATOLOGY website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html).

Pathologic spectrum and prognostic significance of underlying liver disease in hepatocellular carcinoma

Although controversy persists about the influence of cirrhosis on the incidence of portal vein invasion and other prognostic indicators of recurrence and survival (e.g., histologic grade, mitotic activity, multiplicity), it is clear that the degree of cirrhosis is important for the long-term survival of patients with HCC. Multicentricity is especially important because it reflects the field carcinogenesis associated with viral hepatitis and particularly chronic HCV infection [59]. A better understanding of the different mechanisms linked to tumor recurrence will help select the best candidates for curative surgery and help tailor adjuvant therapy, such as interferon therapy, to each patient [60]. Finally, the importance of vascular invasion, number of tumors, and tumor size of HCCs in addition to the effect of fibrosis has led Vauthey et al [20] to propose a simplified staging of HCC with better prognostication of survival.

Prognostic histologic indicators of curatively resected hepatocellular carcinomas: a multi-institutional analysis of 425 patients with definition of a histologic prognostic index

Despite growing information on the clinical behavior of hepatocellular carcinoma, the histologic features associated with survival are not well characterized. Clinical and pathologic data on 425 patients who underwent complete resection for hepatocellular carcinoma were reviewed. Six microscopic features, namely, microvascular invasion, nuclear pleomorphism, mitosis, tumor architecture, growth interface, and tumor necrosis, were examined. Independent predictors of survival were identified and combined into a simple prognostic index. By univariate analysis, microvascular invasion, seen in 51.3% of patients (p <0.001), nuclear grade 3, present in 42% of the cases (p <0.001), and mitosis (p <0.008) were significant predictors of poor survival. Hepatocellular carcinoma with a compact growth pattern had a better prognosis as compared with macrotrabecular (p = 0.014) and acinar (p = 0.051) patterns. By multiple regression analysis, only microvascular invasion (p <0.001) and nuclear grade 3 (p = 0.008) were independent predictors of poor survival. The predictive values of microvascular invasion and nuclear grade allowed the construction of a hepatocellular prognostic index (HPI) whereby HPI = (microvascular invasion status x 0.459) + (nuclear grade x 0.287), with microvascular invasion either absent (0) or present (1) and nuclear grade scored as 1, 2, or 3. Using a cut-off of 0.746 (corresponding to at least nuclear grade 2 with microvascular invasion), two groups could be segregated: fair prognosis (HPI < or = 0.746), with a 50% survival of 5.06 years, and poor prognosis (HPI >0.746) with a 50% survival of 2.71 years (p <0.001). HPI was more discriminating than Edmondson grade, with Edmondson II hepatocellular carcinomas dispersed in both fair and poor prognosis groups. Microvascular invasion and nuclear grade 3 emerge as strong prognostic indicators, and their combination provides adequate prognostic stratification. Practically, hepatocellular carcinoma can be stratified in two groups with regard to prognosis: 1) fair prognosis group (nuclear grade 1 with or without microvascular invasion and nuclear grade 2 without microvascular invasion), and 2) poor prognosis (nuclear grade 2 with microvascular invasion and nuclear grade 3 with or without microvascular invasion). The combination of these histologic parameters provides adequate prognostic stratification.

A growth-constrained environment drives tumor progression invivo

We recently have shown that selective growth of transplanted normal hepatocytes can be achieved in a setting of cell cycle block of endogenous parenchymal cells. Thus, massive proliferation of donor-derived normal hepatocytes was observed in the liver of rats previously given retrorsine (RS), a naturally occurring alkaloid that blocks proliferation of resident liver cells. In the present study, the fate of nodular hepatocytes transplanted into RS-treated or normal syngeneic recipients was followed. The dipeptidyl peptidase type IV-deficient (DPPIV(-)) rat model for hepatocyte transplantation was used to distinguish donor-derived cells from recipient cells. Hepatocyte nodules were chemically induced in Fischer 344, DPPIV(+) rats; livers were then perfused and larger (>5 mm) nodules were separated from surrounding tissue. Cells isolated from either tissue were then injected into normal or RS-treated DPPIV(-) recipients. One month after transplantation, grossly visible nodules (2--3 mm) were seen in RS-treated recipients transplanted with nodular cells. They grew rapidly, occupying 80--90% of the host liver at 2 months, and progressed to hepatocellular carcinoma within 4 months. By contrast, no liver nodules developed within 6 months when nodular hepatocytes were injected into the liver of recipients not exposed to RS, although small clusters of donor-derived cells were present in these animals. Taken together, these results directly point to a fundamental role played by the host environment in modulating the growth and the progression rate of altered cells during carcinogenesis. In particular, they indicate that conditions associated with growth constraint of the host tissue can drive tumor progression in vivo.