Hironori Haga

Validation of the IASLC/ATS/ERS Lung Adenocarcinoma Classification for Prognosis and Association with EGFR and KRAS Gene Mutations: Analysis of 440 Japanese Patients

Introduction: This study aimed to validate the utility of the new histological classification proposed by the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS), and European Respiratory Society (ERS) for identifying the prognostic subtypes of adenocarcinomas in Japanese patients; correlations between the classification and the presence of EGFR or KRAS mutation status were also investigated. Methods: We retrospectively reviewed 440 patients with lung adenocarcinoma, who underwent resection. The tumors were classified according to the IASLC/ATS/ERS classification. EGFR and KRAS mutations were detected using the established methods. Results: Five-year disease-free survival rates were: 100% for adenocarcinoma in situ (n = 20) and minimally invasive adenocarcinoma (n = 33), 93.8% for lepidic-predominant adenocarcinoma (n = 36), 88.8% for invasive mucinous adenocarcinoma (n = 10), 66.7% for papillary-predominant adenocarcinoma (n = 179), 69.7% for acinar-predominant adenocarcinoma (n = 61), 43.3% for solid-predominant adencoarcinoma (n = 78), and 0% for micropapillary-predominant adenocarcinoma (n = 19). Multivariate analysis revealed that the new classification was an independent predictor of disease-free survival. EGFR and KRAS mutations were detected in 90 cases (53.9%) and 21 cases (13.3%), respectively; EGFR mutations were significantly associated with adenocarcinoma in situ, minimally invasive adenocarcinoma, lepidic- and papillary-predominant adenocarcinoma, and KRAS mutations adenocarcinomas with mucinous tumor subtypes. Conclusions: We found that the IASLC/ATS/ERS classification identified prognostic histologic subtypes of lung adenocarcinomas among Japanese patients. Histologic subtyping and molecular testing for EGFR and KRAS mutations can help predict patient prognosis and select those who require adjuvant chemotherapy.

Biliary intraepithelial neoplasia: an international interobserver agreement study and proposal for diagnostic criteria

Cholangiocarcinoma of the intrahepatic and extrahepatic bile ducts develops through a multistep histopathologic sequence. Premalignant or non-invasive neoplastic lesions of bile ducts have been historically called biliary dysplasia or atypical biliary epithelium. To this date, no standard terminology or classification system has been offered for these lesions. In 2005, a conceptual framework and diagnostic criteria for biliary intraepithelial neoplasia (BilIN) were proposed using the livers of patients with hepatolithiasis. We report herein an international interobserver agreement study on the diagnosis of biliary non-invasive neoplastic lesions with the goal to obtain a consensus on the terminology and grading. Seventeen pathologists from the United States, Europe and Asia participated in this study. They shared a digital file containing histological pictures of 30 foci of non-invasive neoplastic lesions selected from the biliary system of patients suffering from primary sclerosing cholangitis, choledochal cyst or hepatolithiasis. In the criteria, we proposed in 2005, BilIN was classified into three categories based on the degree of atypia: BilIN-1, BilIN-2 and BilIN-3. In this study, consensus was reached for the terminology of BilIN and the three-grade classification system. Interobserver agreement on the diagnosis was moderate (κ-value=0.45). On the basis of the suggestions and opinions obtained from the 17 participants, the original criteria for BilIN were revised. We now propose a new consensus classification of BilIN that may assist in allowing a more uniform terminology for the diagnosis of biliary non-invasive neoplastic lesions. This classification should help to advance clinical and research applications.

Expansion of selection criteria for patients with hepatocellular carcinoma in living donor liver transplantation

In the present study, the results of living donor liver transplantation (LDLT) for 125 hepatocellular carcinoma (HCC) patients were analyzed to determine optimal criteria exceeding the Milan criteria (MC) but still with predictably good outcomes. On the basis of pretransplant imaging studies, 70 patients met the MC, and 55 patients did not. Patients who exceeded the MC but presented with ≤10 tumors all ≤5 cm in diameter (n = 30) displayed 5‐year recurrence rates (7.3%) similar to those of patients within the MC (9.7%, P = 0.8787). According to the results of multivariate analysis of risk factors for recurrence among preoperative tumor variables, we have defined the new criteria, namely ≤10 tumors all ≤5 cm in diameter and protein induced by vitamin K absence or antagonist‐II (PIVKA‐II) ≤400 mAU/mL. The 78 patients who met the new criteria showed significantly lower 5‐year recurrence rates (4.9%) than the 40 patients who exceeded them (60.5%, P < 0.0001). Similarly, 5‐year survival rates significantly differed between these groups (86.7% versus 34.4%, respectively; P < 0.0001). In conclusion, selection criteria for patients with HCC undergoing LDLT may be safely extended to ≤10 tumors all ≤5 cm in diameter and PIVKA‐II ≤400 mAU/mL with acceptable outcomes. Liver Transpl 13: 1637–1644, 2007.

Present status of ABO‐incompatible living donor liver transplantation in Japan

ABO‐incompatible (ABO‐I) living donor liver transplantation (LDLT) has been performed in Japan to overcome the organ shortage. Reported herein are the results of this approach through March 2006 in the National Registry of the Japan Study Group for ABO‐incompatible transplantation. The questionnaires consisted of patient characteristics, operative data, and strategies for preventing antibody‐mediated rejection (AMR). Data of 291 patients (follow‐up period, 8 months‐15 years; mean, 35 months) from 28 institutions were collected. Age was younger than 1 year in 68 patients, 1 to 7 years in 60 patients, 8 to15 years in 27 patients, and 16 years or older in 136 patients. The strategy for the blood‐type barrier was heterogeneous in terms of recipient age, transplant center, and era. Local infusion and rituximab prophylaxis were applied in 2000 and 2003, respectively. The 5‐year patient survival rate was 85% in infants and 52% in adults. The major causes of death were infection and antibody‐mediated rejection (AMR). Multivariate analysis showed that age group, preoperative condition, antibody titer, and infection significantly affected survival. Age group, antibody titer, and local infusion treatment significantly affected the incidence of AMR. Patient survival rates were significantly higher and the incidence of AMR was significantly lower in adult patients after 2000 (3 year‐survival rate, 29%, 56%, and 61%; incidence of AMR, 47%, 27%, and 16%, through May 2000, from June 2000 through October 2003, and from November 2003, respectively). Conclusion: ABO‐incompatible LDLT is a standard practice in children, and local infusion and rituximab prophylaxis are promising in adults. (HEPATOLOGY 2007.)

Impact of recipient age on outcome of ABO-incompatible living-donor liver transplantation.

Background. Transplantation of hepatic grafts from ABO-incompatible donors is controversial because of the risk of hyperacute rejection mediated by preformed anti-ABO antibodies. The aim of the present study was to evaluate the outcome of liver transplants performed with ABO-incompatible living-donor livers and to detect risk factors for development of complications. Methods. From June 1990 to February 2000, 66 patients, 10 months to 55 years old (median, 2 years old), received 68 ABO-incompatible living-donor liver grafts. The antibody titer and clinical course were followed prospectively during a period ranging from 3 to 11 years. Results. The 5-year patient survival was 59%, 76%, and 80% for ABO-incompatible, ABO-compatible, and ABO-identical grafts, respectively (P <0.01). In patients <1 year old, ≥1 to <8, ≥8 to <16, and and ≥16 years old, 5-year survival was 76%, 68%, 53%, and 22%, respectively. The incidence of intrahepatic biliary complications and hepatic necrosis in ABO-incompatible living-related grafts (18% and 8%, respectively) was significantly (P <0.0001) greater than in ABO-compatible and ABO-identical grafts (both 0.6% and 0%, respectively). Predictive risk factors for increased mortality and morbidity were age greater than 1 year and elevated anti-ABO titers before transplantation. Conclusions. ABO-incompatible liver transplantation was carried out with relative safety in infants <1 year old but was not satisfactory in children >1 year in long-term follow-up. Patients aged >8 years remain at considerable risk of early fatal outcome because of hepatic necrosis, and new strategies to prevent antibody-mediated rejection are required.

Outcomes of adult-to-adult living donor liver transplantation : a single institution's experience with 335 consecutive cases

Objective:To determine outcomes for both donors and recipients of adult-to-adult living donor liver transplantation (AALDLT) and independent factors impacting those outcomes. Summary Background Data:Deceased donors for organ transplantation remain extremely rare, making living donor liver transplantation (LDLT) practically the sole therapeutic modality for patients with end-stage liver disease in Japan. Methods:Retrospective analysis of initial LDLT for 335 consecutive adult (≥18 years) patients performed between November 1994 and December 2003. Results:Of the 335 recipients, 275 received right-liver grafts and the remaining 60 recipients received non-right-liver grafts. Three of the 335 liver grafts were domino-splitting livers. Sixty of the 332 donors other than the domino-donors showed major postoperative complications. Multivariate analysis indicated that accumulation of case experience significantly and advantageously affected the surgical outcomes of these living liver donors, and right-liver donation and prolonged donor operation time were shown to be independent risk factors of major complications in the donors. Post-transplant patient and graft survival estimates were 73.1% and 72.5% at 1 year, 67.7% and 66.3% at 4 years, and 64.7% and 61.9% at 7 years, respectively. Obvious pretransplant encephalopathy, a higher (≥31) modified Model for End-stage Liver Disease score (including points for persistent ascites and low serum sodium) and higher donor age (≥50 years) were indicated as independent factors predictive of graft failure (graft loss or death) in the multivariate analysis. Conclusions:Graft type and degree of experience exerted a significant impact on the surgical outcomes of AALDLT donors but did not significantly affect the survival outcomes of AALDLT recipients. Better pretransplant conditions and younger age (<50 years) among the living donors appeared to be advantageous in terms of gaining better survival outcomes of patients undergoing AALDLT.

Noninvasive evaluation of graft steatosis in living donor liver transplantation

Background. Hepatic steatosis affects graft function as well as postoperative recovery of donors in living donor liver transplantation. Liver macrovesicular steatosis in living donors was assessed using quantitative X-ray computed tomography (CT) analysis and histological examination of intraoperative liver biopsy. Methods. A total of 266 living donors with complete pretransplant CT data and intraoperative “time 0” biopsy were included in the study. Liver biopsy specimen obtained during donor operation was examined for macrovesicular steatosis and was classified as none; mild (<30%); moderate (30%–60%); or severe (>60%). Liver-to-spleen CT attenuation values ratio (L/S ratio) on noncontrast-CT was evaluated for its usefulness as an index of hepatic steatosis in comparison with other parameters including body mass index (BMI) and serum liver function tests (gamma-glutamyl transpeptidase, alanine aminotransferase, aspartate aminotransferase, cholinesterase, and total cholesterol) using receiver operating characteristic (ROC) analysis. Results. Histological grade of macrovesicular steatosis was none in 198 patients (74.4%), mild in 50 (18.8%), moderate in 15 (5.7%), and severe in 3 (1.1%). The median L/S ratios for the respective histological grades were 1.20 (range: 1.00–1.46), 1.12 (0.83–1.37), 1.01 (0.74–1.21), and 0.90 (0.70–0.99) (P<0.0001). The ROC curve for L/S ratio was located closest to the upper left corner, and the area under the curve of L/S ratio was significantly larger than that of any other preoperative variables. Conclusion. L/S ratio calculated from preoperative CT can be a useful tool to discriminate hepatic macrovesicular steatosis. Based on the present results, the optimal cut-off value for L/S ratio to exclude more than moderate steatosis would be 1.1.

Risk of Cancer in Patients With Autoimmune Pancreatitis

OBJECTIVES:Although simultaneous occurrences of autoimmune pancreatitis (AIP) and cancer are occasionally observed, it remains largely unknown whether cancer and AIP occur independently or these disorders are interrelated. The aim of this study was to examine the relationship between AIP and cancer.METHODS:We conducted a multicenter, retrospective cohort study. One hundred and eight patients who met the Asian diagnostic criteria for AIP were included in the study. We calculated the proportion, standardized incidence ratio (SIR), relative risk, and time course of cancer development in patients with AIP. We also analyzed the clinicopathological characteristics of AIP patients with cancer in comparison with those without cancer.RESULTS:Of the 108 AIP patients, 18 cancers were found in 15 patients (13.9%) during the median follow-up period of 3.3 years. The SIR of cancer was 2.7 (95% confidence interval (CI) 1.4–3.9), which was stratified into the first year (6.1 (95% CI 2.3–9.9)) and subsequent years (1.5 (95% CI 0.3–2.8)) after AIP diagnosis. Relative risk of cancer among AIP patients at the time of AIP diagnosis was 4.9 (95% CI 1.7–14.9). In six of eight patients whose cancer lesions could be assessed before corticosteroid therapy for AIP, abundant IgG4-positive plasma cell infiltration was observed in the cancer stroma. These six patients experienced no AIP relapse after successful cancer treatment.CONCLUSIONS:Patients with AIP are at high risk of having various cancers. The highest risk for cancer in the first year after AIP diagnosis and absence of AIP relapse after successful treatment of the coexisting cancers suggest that AIP may develop as a paraneoplastic syndrome in some patients.

Expression of activation-induced cytidine deaminase in human hepatocytes during hepatocarcinogenesis

Activation‐induced cytidine deaminase (AID) plays a role as a genome mutator in activated B cells, and inappropriate expression of AID has been implicated in the immunopathological phenotype of human B‐cell malignancies. Notably, we found that the transgenic mice overexpressing AID developed lung adenocarcinoma and hepatocellular carcinoma (HCC), suggesting that ectopic expression of AID can lead to tumorigenesis in epithelial tissues as well. To examine the involvement of AID in the development of human HCC, we analyzed the AID expression and its correlation with mutation frequencies of the p53 gene in liver tissues from 51 patients who underwent resection of primary HCCs. The specific expression, inducibility by cytokine stimulation and mutagenic activity of AID were investigated in cultured human hepatocytes. Only trace amounts of AID transcripts were detected in the normal liver; however, endogenous AID was significantly upregulated in both HCC and surrounding noncancerous liver tissues with underlying chronic hepatitis or liver cirrhosis (p < 0.05). Most liver tissues with underlying chronic inflammation with endogenous AID upregulation already contained multiple genetic changes in the p53 gene. In both hepatoma cell lines and cultured human primary hepatocytes, the expression of AID was substantially induced by TGF‐β stimulation. Aberrant activation of AID in hepatocytes resulted in accumulation of multiple genetic alterations in the p53 gene. Our findings suggest that the aberrant expression of AID is observed in human hepatocytes with several pathological settings, including chronic liver disease and HCC, which might enhance the genetic susceptibility to mutagenesis leading to hepatocarcinogenesis.

The Presence of Foxp3 Expressing T Cells Within Grafts of Tolerant Human Liver Transplant Recipients

Background. Some experimental transplant-tolerance models have shown that the presence of regulatory T cells within grafts is important for the development of tolerance (Tol). Methods. To determine if the presence of regulatory T cells correlates with graft acceptance in living-donor liver-transplantation tolerance, the expression of Foxp3 mRNA and the presence of CD4+, CD8+, and Foxp3+ cells were quantified in biopsies from tolerant recipients by real-time polymerase chain reaction and by immunohistochemistry and immunofluorescent staining (Gr-Tol). The results were compared with biopsies from the recipients on maintenance immunosuppression (Gr-IS), grafts removed because of chronic rejection (Gr-CR), or normal liver (Gr-NL). Results. The expression of Foxp3 mRNA in Gr-Tol was higher than that in Gr-IS (P=0.07) and Gr-NL (P<0.0001), but equivalent to that in Gr-CR. In Gr-Tol, Foxp3+ cells were detectable within the clustered CD4+ and CD8+ cells in the portal areas. Ninety-two percent of those Foxp3+ cells were CD4+, whereas 8% were CD8+. The number of Foxp3+ cells was significantly increased in Gr-Tol, compared with that in Gr-IS (P<0.05), although the number of CD4+ or CD8+ cells did not differ between the two. Foxp3+ cells were hardly detectable in Gr-CR or -NL. Conclusions. This is the first report showing that CD4+Foxp3+ cells are present within grafts in a subset of tolerant patients after human liver transplantation. A prospective study is needed to elucidate whether the assessment of intragraft expression of Foxp3 protein, but not Foxp3 mRNA, can aid the identification of living-donor liver-transplantation recipients who can successfully withdraw IS.