Person:

Tanabe, Kenneth

Context: Overexpression of epidermal growth factor (EGF) in the liver induces transformation to hepatocellular carcinoma in animal models. Polymorphisms in the EGF gene modulate EGF levels. Objective: To assess the relationship among human EGF gene single-nucleotide polymorphism, EGF expression, and risk of hepatocellular carcinoma. Design, Setting, and Participants: Molecular mechanisms linking the 61G allele polymorphism to EGF expression were examined in human hepatocellular carcinoma cell lines and human liver tissue. A case-control study involving 207 patients with cirrhosis was conducted at the Massachusetts General Hospital (1999-2006) and a validation case-control study involving 121 patients with cirrhosis was conducted at Hôpital Paul Brousse (1993-2006). Restriction fragment-length polymorphism was used to determine the EGF gene polymorphism genotype. Logistic regression analysis was used to assess the association between the EGF polymorphism and hepatocellular carcinoma risk. Main Outcome Measures: Mechanisms by which the EGF gene polymorphism modulates EGF levels and associations among EGF gene polymorphism, EGF levels, and hepatocellular carcinoma. Results: Transcripts from the EGF 61G allele exhibited more than a 2-fold longer half-life than those from the 61*A allele, and EGF secretion was 2.3-fold higher in G/G hepatocellular carcinoma cell lines than A/A cell lines. Serum EGF levels were 1.8-fold higher in G/G patients than A/A patients, and liver EGF levels were 2.4-fold higher in G/G patients than A/A patients. Among the 207 patients with cirrhosis in the Massachusetts study population, 59 also had hepatocellular carcinoma. Analysis of the distribution of allelic frequencies revealed that there was a 4-fold odds of hepatocellular carcinoma in G/G patients compared with A/A patients in the Massachusetts study population (odds ratio, 4.0; 95% confidence interval [CI], 1.6-9.6; P = .002). Logistic regression analysis demonstrated that the number of copies of G was significantly associated with hepatocellular carcinoma after adjusting for age, sex, race, etiology, and severity of cirrhosis (G/G or A/G vs A/A; hazard ratio, 3.49; 95% CI, 1.29-9.44; P = .01). The significant association was validated in the French patients with alcoholic cirrhosis and hepatocellular carcinoma. Conclusion: The EGF gene polymorphism genotype is associated with risk for development of hepatocellular carcinoma in liver cirrhosis through modulation of EGF levels.

Objectives: To determine the prevalence of incidentally found cases of gallbladder cancer, the incidence of residual disease at reexploration, and the changes in the mode of presentation, treatment, and survival of patients with gallbladder cancer during a period of more than 4 decades. Design: Retrospective case series. Setting: University-affiliated tertiary care center. Patients: Between January 1, 1962, and March 1, 2008, 402 patients with gallbladder cancer were identified and their clinicopathologic data were analyzed. Interventions: Surgical treatment, radiotherapy, and chemotherapy. Main Outcome Measures: Incidentally discovered gallbladder cancer, incidence of residual disease, and differences in presentation, treatment, and survival. Results: Surgical exploration was performed in 260 patients (64.7%), of whom 151 (58.1%) underwent resection. The median age of the patients was 72 years, and 72.3% were female. Between January 1, 1994, and March 1, 2008, 6881 laparoscopic cholecystectomies were performed, and there were 17 incidentally discovered cases of gallbladder cancer (0.25%). Residual disease on reexploration was identified in 0 of 2 patients with T1 tumor, 3 of 13 patients with T2 tumor, and 8 of 10 patients with T3 tumor (P = .01). Patients with stage IV disease (34 [13.1%] diagnosed from 1962-1979; 34 [13.1%] diagnosed from 1980-1997; and 22 [8.5%] diagnosed from 1998-2008) had a median survival of 4 months (range, 0-37 months). Concomitant liver resections increased in the third study period (11.1%, 10.1%, and 54.3%; P < .001), with an increase in negative margins (33.3%, 42.0%, and 63.0%; P = .01). Cox regression analysis identified T stage and surgical margin status as significant prognostic factors. Conclusions: Gallbladder cancer is incidentally found during 0.25% of laparoscopic cholecystectomies. As T stage increases, the likelihood of residual disease on reexploration increases. Although many patients with gallbladder cancer present with incurable disease and have very poor survival, the overall prognosis is improving, likely because of more extensive operations.

AIMS: Because of its efficacy, oxaliplatin (OX) is increasingly used as a chemotherapeutic agent in the treatment of colorectal liver metastases (CRLM). Oxaliplatin-associated liver toxicity has been reported and can affect clinical practice, but studies on its prevalence and a full pathological description are lacking. The aims of this study were to fill this gap by providing, from a pathologist's perspective, a detailed assessment of the spectrum of hepatic lesions associated with OX, to suggest a scoring system to quantify them, and to investigate the protective effect of bevacizumab against OX-associated damage. METHODS AND RESULTS: The spectrum of oxaliplatin-associated liver lesions was investigated in a multi-institutional series of surgically resected CRLM (n = 385). Among 274 patients treated by OX, 54% had moderate/severe sinusoidal obstruction syndrome (SOS). Peliosis, centrilobular perisinusoidal/venular fibrosis and nodular regenerative hyperplasia (NRH) developed in 10.6%, 47% and 24.5%, respectively. The 111 patients treated by surgery alone had no lesions. Hepatic lesions were less severe in patients treated with OX/bevacizumab (n = 70) compared with the group treated by OX alone (n = 204), with an incidence of moderate/severe SOS (31.4% versus 62.2%), peliosis (4.3% versus 14.6%), NRH (11.4% versus 28.9%, respectively) and centrilobular/venular fibrosis (31.4% versus 52%, respectively) (P < 0.001). CONCLUSIONS: Pathologists should be aware of the distinctive lesions associated with OX and of their high prevalence. OX-related lesions are less frequent in patients treated with bevacizumab, suggesting that this drug has a preventive effect. Uniform criteria for diagnosis and grading of OX-associated lesions should help to include histological data in the optimal multidisciplinary management of CRLM.

Background & Aims: Liver biopsy, the current clinical gold standard for fibrosis assessment, is invasive and has sampling errors, and is not optimal for screening, monitoring, or clinical decision-making. Fibrosis is characterized by excessive accumulation of extracellular matrix proteins including type I collagen. We hypothesize that molecular magnetic resonance imaging (MRI) with a probe targeted to type I collagen could provide a direct and non-invasive method of fibrosis assessment. Methods: Liver fibrosis was induced in rats with diethylnitrosamine and in mice with carbon tetrachloride. Animals were imaged prior to and immediately following i.v. administration of either collagen-targeted probe EP-3533 or non-targeted control Gd-DTPA. Magnetic resonance (MR) signal washout characteristics were evaluated from T1 maps and T1-weighted images. Liver tissue was subjected to pathologic scoring of fibrosis and analyzed for gadolinium and hydroxyproline. Results: EP-3533-enhanced MR showed greater signal intensity on delayed imaging (normalized signal enhancement mice: control = 0.39 ± 0.04, fibrotic = 0.55 ± 0.03, p <0.01) and slower signal washout in the fibrotic liver compared to controls (liver t1/2 = 51.3 ± 3.6 vs. 42.0 ± 2.5 min, p <0.05 and 54.5 ± 1.9 vs. 44.1 ± 2.9 min, p <0.01 for fibrotic vs. controls in rat and mouse models, respectively). Gd-DTPA-enhanced MR could not distinguish fibrotic from control animals. EP-3533 gadolinium concentration in the liver showed strong positive correlations with hydroxyproline levels (r = 0.74 (rats), r = 0.77 (mice)) and with Ishak scoring (r = 0.84 (rats), r = 0.79 (mice)). Conclusions: Molecular MRI of liver fibrosis with a collagen-specific probe identifies fibrotic tissue in two rodent models of disease.

Background & Aims The gold standard in assessing liver fibrosis is biopsy despite limitations like invasiveness and sampling error and complications including morbidity and mortality. Therefore, there is a major unmet medical need to quantify fibrosis non-invasively to facilitate early diagnosis of chronic liver disease and provide a means to monitor disease progression. The goal of this study was to evaluate the ability of several magnetic resonance imaging (MRI) techniques to stage liver fibrosis.

Methods A gadolinium (Gd)-based MRI probe targeted to type I collagen (termed EP-3533) was utilized to non-invasively stage liver fibrosis in a carbon tetrachloride (CCl4) mouse model and the results were compared to other MRI techniques including relaxation times, diffusion, and magnetization transfer measurements.

Results The most sensitive MR biomarker was the change in liver:muscle contrast to noise ratio (ΔCNR) after EP-3533 injection. We observed a strong positive linear correlation between ΔCNR and liver hydroxyproline (i.e. collagen) levels (r = 0.89) as well as ΔCNR and conventional Ishak fibrosis scoring. In addition, the area under the receiver operating curve (AUR0C) for distinguishing early (Ishak ⩽3) from late (Ishak ⩾4) fibrosis was 0.942 ± 0.052 (p <0.001). By comparison, other MRI techniques were not as sensitive to changes in fibrosis in this model.

Conclusions We have developed an MRI technique using a collagen-specific probe for diagnosing and staging liver fibrosis, and validated it in the CCl4 mouse model. This approach should provide a better means to monitor disease progression in patients.

Background: Possible mass lesions identified on ultrasound (US) of the gallbladder may prompt an aggressive surgical intervention due to the possibility of a malignant neoplasm. Aim: This study aims to utilize a large modern series of patients with gallbladder lesions identified on US to evaluate imaging characteristics consistent with malignancy. Methods: A retrospective review was conducted of gallbladder ultrasound reports and clinicopathologic data of patients with a mass identified on US. Results: Approximately 59,271 abdominal ultrasounds and 9,117 cholecystectomies were performed between February 2000 and February 2010. We identified 213 patients with a questionable gallbladder neoplasm on ultrasonography who underwent surgical exploration. Median age was 52 years (range = 11–87 years) and 147 (69%) were females. Final pathology demonstrated no neoplasm in 130 patients (61%), while 32 patients (15%) had a wall adenomyoma, 36 (17%) had a polyp (five of which were malignant), 14 (7%) had an adenocarcinoma not arising from a polyp, and one patient had a cystic papillary neoplasm. The smaller the lesion, the more likely it was to be a pseudo-mass. For lesions measuring <5 mm on US, 83% had no lesion found on final pathology. Significant predictors of malignancy were age >52 years (p < 0.001), presence of gallstones on US (p = 0.004), size >9 mm (p < 0.001), evidence of invasion at the liver interface (p < 0.001), and wall thickening >5 mm (p < 0.001). Shape (sessile or penduculated), echogenicity (echogenic or isoechoic), or presence of flow on Doppler were not predictors of malignancy. An US size of ≤9 mm had a negative predictive value of 100% for malignancy. Conclusions: Despite improvements in imaging, most apparent lesions measuring <5 mm on US are not identified in the surgical specimen. US size >9 mm, age >52 years, US suggestion of invasion at the liver interface, and wall thickening >5 mm, especially in the presence of gallstones, should raise the suspicion of malignancy.

Background: In the setting of chronic liver injury in humans, epidermal growth factor (EGF) and EGF receptor (EGFR) are up-regulated and have been proposed to have vital roles in both liver regeneration and development of hepatocellular carcinoma (HCC). Chronic liver injury also leads to hepatic stellate cell (HSC) differentiation and a novel subpopulation of HSCs which express CD133 and exhibit properties of progenitor cells has been described in rats. The carbon tetrachloride (CCl4)-induced mouse model has been historically relied upon to study liver injury and regeneration. We exposed mice to CCl4 to assess whether EGF and CD133+ HSCs are up-regulated in chronically injured liver. Methods: CCl4 in olive oil was administered to strain A/J mice three times per week by oral gavage. Results: Multiple well-differentiated HCCs were found in all livers after 15 weeks of CCl4 treatment. Notably, HCCs developed within the setting of fibrosis and not cirrhosis. CD133 was dramatically up-regulated after CCl4 treatment, and increased expression of desmin and glial fibrillary acidic protein, representative markers of HSCs, was also observed. EGF expression significantly decreased, contrary to observations in humans, whereas the expression of amphiregulin, another EGFR ligand, was significantly increased. Conclusions: Species-specific differences exist with respect to the histopathological and molecular pathogenesis of chronic liver disease. CCl4-induced chronic liver injury in A/J mice has important differences compared to human cirrhosis leading to HCC.