Integrated analyses of the genetic and clinicopathological features of cholangiolocarcinoma: cholangiolocarcinoma may be characterized by mismatch-repair deficiency.

Cholangiolocarcinoma (CLC) is a primary liver carcinoma that resembles the canals of Hering and that has been reported to be associated with stem cell features. Due to its rarity, the nature of CLC remains unclear, and its pathological classification remains controversial. To clarify the positioning of CLC in primary liver cancers and identify characteristics that could distinguish CLC from other liver cancers, we performed integrated analyses using whole-exome sequencing (WES), immunohistochemistry, and a retrospective review of clinical information on eight CLC cases and two cases of recurrent CLC. WES demonstrated that CLC includes IDH1 and BAP1 mutations, which are characteristic of intrahepatic cholangiocarcinoma (iCCA). A mutational signature analysis showed a pattern similar to that of iCCA, which was different from that of hepatocellular carcinoma (HCC). CLC cells, including CK7, CK19, and EpCAM, were positive for cholangiocytic differentiation markers. However, the hepatocytic differentiation marker AFP and stem cell marker SALL4 were completely negative. The immunostaining patterns of CLC with CD56 and epithelial membrane antigen were similar to those of the noncancerous bile ductules. In contrast, mutational signature cluster analyses revealed that CLC formed a cluster associated with mismatch-repair deficiency (dMMR), which was separate from iCCA. Therefore, to evaluate MMR status, we performed immunostaining of four MMR proteins (PMS2, MSH6, MLH1, and MSH2) and detected dMMR in almost all CLCs. In conclusion, CLC had highly similar characteristics to iCCA but not to HCC. CLC can be categorized as a subtype of iCCA. In contrast, CLC has characteristics of dMMR tumors that are not found in iCCA, suggesting that it should be treated distinctly from iCCA. © 2024 The Pathological Society of Great Britain and Ireland.

Comprehensive analyses of the clinicopathological features and genomic mutations of combined hepatocellular-cholangiocarcinoma.

AIM: Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a rare primary liver cancer that has two different tumor phenotypes in a single tumor nodule. The relationship between genetic mutations and clinicopathological features of cHCC-CCA remains to be elucidated. METHODS: Whole-exome sequencing analyses were carried out in 13 primary and 2 recurrent cHCC-CCAs. The whole-exome analyses and clinicopathological information were integrated. RESULTS: TP53 was the most frequently mutated gene in this cohort, followed by BAP1, IDH1/2, and NFE2L2 mutations in multiple cases. All tumors with diameters <3 cm had TP53 mutations. In contrast, six of seven tumors with diameters ≥3 cm did not have TP53 mutations, but all seven tumors had mutations in genes associated with various pathways, including Wnt, RAS/PI3K, and epigenetic modulators. In the signature analysis, the pattern of mutations shown in the TP53 mutation group tended to be more similar to HCC than the TP53 nonmutation group. Mutations in recurrent cHCC-CCA tumors were frequently identical to those in the primary tumor, suggesting that those tumors originated from identical clones of the primary cHCC-CCA tumors. Recurrent and co-occurrent HCC tumors in the same patients with cHCC-CCA had either common or different mutation patterns from the primary cHCC-CCA tumors in each case. CONCLUSIONS: The study suggested that there were two subtypes of cHCC-CCA, one involving TP53 mutations in the early stage of the carcinogenic process and the other not involving such mutations. The comparison of the variants between primary and recurrent tumors suggested that cHCC-CCA was derived from an identical clone.

Albumin-Bilirubin Score at Post-Hepatectomy Hepatocellular Carcinoma Recurrence: Impact on Survival and Association with Post-Hepatectomy Liver Failure.

PURPOSE: Our objective was to investigate the impact of albumin-bilirubin (ALBI) score at the time of post-hepatectomy hepatocellular carcinoma (HCC) recurrence on survival after recurrence (SAR). We further explored the perioperative factors associated with the ALBI score at recurrence. METHODS: Patients who underwent primary hepatectomy for HCC between 2007 and 2018 and developed recurrence were included in the study. Cox regression models were used to assess the association between the ALBI score at recurrence and SAR. Linear regression models were used to explore factors associated with ALBI score at recurrence. RESULTS: Of the 233 patients analyzed, 158 developed recurrence within the Milan criteria (RWM) and 76 developed recurrence beyond the Milan criteria (RBM). Multivariable cox regression analysis demonstrated that higher ALBI scores at recurrence were associated with poorer SAR in both RWM and RBM groups (hazard ratios 4.5, 5.0; 95% confidence intervals 2.3-8.8, 2.2-11.6, respectively). In addition, multivariable linear regression analysis revealed that higher ALBI scores at hepatectomy and post-hepatectomy liver failure (PHLF) ≥ grade B were associated with higher ALBI scores at recurrence (ß = 0.21, 0.11; 95% confidence intervals 0.15-0.26, 0.06-0.17, respectively). CONCLUSIONS: The ALBI score at recurrence was a significant prognostic factor for SAR, and the ALBI scores at hepatectomy and PHLF ≥ Grade B were independently associated with the ALBI score at recurrence. Prevention of PHLF and consequent preservation of liver function at recurrence may be paramount to achieving better survival after HCC recurrence.

[Locally Advanced Gastric Cancer Showing Marked Tumor Shrinkage after the First Dose of Nivolumab for Fourth-Line Chemotherapy].

We report a case of locally advanced gastric cancer, which showed marked tumor shrinkage after the first dose of nivolumab. A 75-year-old woman was diagnosed with locally advanced gastric cancer with pancreatic invasion and pyloric stenosis. We performed gastrojejunostomy before chemotherapy. The first-line, second-line, and third-line chemotherapies were not effective, resulting in tumor progression and necrosis with abdominal wall penetration. Her performance status was good, so we started nivolumab therapy as the fourth-line chemotherapy. Nine days after the first dose of nivolumab, she had a severe abdominal pain and a sense of fatigue. CT imaging showed a remarkable degree of tumor necrosis just beneath the skin. We diagnosed progressive disease and discontinued the chemotherapy. However, her general condition gradually improved and CT imaging 4 months after the first dose of nivolumab showed marked tumor shrinkage. We restarted nivolumab therapy and she has been alive for 2 years 10 months since the introduction of chemotherapy. It was suggested that a single dose of nivolumab only could lead to marked tumor shrinkage in chemotherapy for advanced gastric cancer.

Capillary hemangioma involved in filar lipoma: A case report.

Filar lipomas are a subtype of spinal lipomas wherein adipose tissue accumulation is restricted to the filum terminale. Embryologically, filar lipomas are considered to occur because of the failure of secondary neurulation, although the precise mechanism is not yet completely understood. Involvement of ectopic mesodermal, ectodermal, and endodermal tissues in spinal lipomas has been occasionally reported, and the origin of these ectopic tissues has been supposed to be migration of pluripotent tissues, which exist during secondary neurulation. We report an infantile case of capillary hemangioma involved in filar lipoma. To our knowledge, this is the first report of a case of intradural extramedullary capillary hemangioma at the filum terminale. We suspected that the filar lesion arose during the late phase of secondary neurulation based on the clinical, anatomical, and histological characteristics.
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Infection dynamics of Toxoplasma gondii in gut-associated tissues after oral infection: The role of Peyer's patches.

Toxoplasma gondii is a common perorally transmitted parasite; however, its immunopathogenesis in gut-associated tissues remains unclear. Here, we compared disease manifestation in C57BL/6 immunocompetent wild type (WT) mice and immunocompromised interferon (IFN)-γ-deficient (GKO) mice after peroral infection (PI) with T. gondii cysts (Fukaya strain). Strong PI-induced Th1 cytokine expression was detected in WT mice. Moreover, bradyzoite-specific T.g.HSP30/bag1 mRNA was detected in the ileum parenchyma and Peyer's patches (PP), but not in the mesenteric lymph nodes, at 7 days post-infection in WT mice, and was significantly higher than that in GKO mice. Nested PCR showed that parasites existed in ileum parenchyma at days 1 and 1.5 post-PI in GKO and WT mice, respectively. In addition, quantitative competitive-PCR indicated that T. gondii first colonized the PP (day 3 post-PI), followed by the ileum parenchyma and mesenteric lymph nodes, spleen, and portal and aortic blood (day 7 post-PI). Although parasites were consistently more abundant in GKO mice, similar invasion and dissemination patterns were observed in the two hosts. Collectively, these data suggest that some zoites differentiate from tachyzoites to bradyzoites in the ileum and that T. gondii initially invades the ileum parenchyma, and then accumulates and proliferates in the PP before disseminating through the lymphatic systems of both GKO and WT hosts.

Histological features of primary tumors after induction or high-dose chemotherapy in high-risk neuroblastoma.

PURPOSE: In the recent years in Japan, an increasing number of patients with neuroblastoma (NB) are being treated by the "delayed local treatment (DL)" policy, undergoing surgery after the completion of high-dose chemotherapy with hematopoietic stem cell rescue (HDC). We reviewed the histopathological findings of second-look operations, including those of patients treated with DL. PATIENTS: From 1998 to 2013, 26 patients with high-risk NB underwent radical operation following chemotherapy. Surgery was performed after induction chemotherapy in 17 cases (standard; STD), whereas 9 cases completed induction chemotherapy and HDC before undergoing tumor resection (DL). The amount of necrosis and the degree of differentiation within the post-treatment tumor were assessed. RESULTS: Eighty-eight percent of the tumors showed necrosis in more than 1/3 of the specimen. Two DL cases showed complete disappearance of viable tumor cells. Amount of necrosis did not affect the prognosis of the patient. Tumors with immature, poorly differentiated phenotypes showed an extremely aggressive thereafter. Though not statistically proven, (123)I-MIBG (metaiodobenzylguanidine) uptake may be correlated with the amount of viable cells remaining within the tumor, but not with the degree of differentiation. CONCLUSIONS: Our results support the previous reports advocating that tumors that sustain unfavorable histology after chemotherapy behave aggressively thereafter.

Metabolic profiling of urine and blood plasma in rat models of drug addiction on the basis of morphine, methamphetamine, and cocaine-induced conditioned place preference.

The metabolic profiles of urine and blood plasma in drug-addicted rat models based on morphine (MOR), methamphetamine (MA), and cocaine (COC)-induced conditioned place preference (CPP) were investigated. Rewarding effects induced by each drug were assessed by use of the CPP model. A mass spectrometry (MS)-based metabolomics approach was applied to urine and plasma of MOR, MA, and COC-addicted rats. In total, 57 metabolites in plasma and 70 metabolites in urine were identified by gas chromatography-MS. The metabolomics approach revealed that amounts of some metabolites, including tricarboxylic acid cycle intermediates, significantly changed in the urine of MOR-addicted rats. This result indicated that disruption of energy metabolism is deeply relevant to MOR addiction. In addition, 3-hydroxybutyric acid, L-tryptophan, cystine, and n-propylamine levels were significantly changed in the plasma of MOR-addicted rats. Lactose, spermidine, and stearic acid levels were significantly changed in the urine of MA-addicted rats. Threonine, cystine, and spermidine levels were significantly increased in the plasma of COC-addicted rats. In conclusion, differences in the metabolic profiles were suggestive of different biological states of MOR, MA, and COC addiction; these may be attributed to the different actions of the drugs on the brain reward circuitry and the resulting adaptation. In addition, the results showed possibility of predict the extent of MOR addiction by metabolic profiling. This is the first study to apply metabolomics to CPP models of drug addiction, and we demonstrated that metabolomics can be a multilateral approach to investigating the mechanism of drug addiction.

International pediatric liver cancer pathological classification: current trend.

This review describes the pathological classification of pediatric liver cancer types and subtypes proposed at the recent international symposium (March 2011, Los Angeles, USA) and meetings involving pathologists serving as central reviewers for the Children's Oncology Group, Société Internationale d'Oncologie Pédiatrique, Gesellschaft für Pädiatrische Onkologie und Hämatologie, or Japanese Study Group for Pediatric Liver Tumors, and pediatric oncologists/surgeons specializing in liver cancers, as well as immunohistochemical panels, recommendations for submission, sampling and evaluation of diagnostic specimens. The pathological classification is intended to be standardized and clinically meaningful, thus improving future patient management and prognosis. The most common pediatric liver cancer is hepatoblastoma (HBL). HBL has two types, the wholly epithelial type and the mixed epithelial and mesenchymal (MEM) type. The wholly epithelial type was subdivided into well-differentiated fetal (pure fetal with low mitotic activity), crowded fetal (mitotically active), embryonal, epithelial mixed, small cell undifferentiated, and cholangioblastic. A macrotrabecular pattern and a pleomorphic epithelial pattern were recognized as supplemental features of epithelial components. The MEM type was subdivided into MEM without teratoid features and MEM with teratoid features. Other liver cancers in children were divided into hepatocellular carcinoma (classic hepatocellular carcinoma and fibrolamellar carcinoma) and hepatocellular malignant tumor not otherwise specified. This classification is basically applied to pretreatment specimens; the evaluation of post-chemotherapy specimens will be the subject of further studies.

Sacrococcygeal yolk sac tumor developing after teratoma: a clinicopathological study of pediatric sacrococcygeal germ cell tumors and a proposal of the pathogenesis of sacrococcygeal yolk sac tumors.

PURPOSE: We evaluated the clinicopathological characteristics of pediatric sacrococcygeal germ cell tumors (SGCTs) and yolk sac tumors (YSTs) developing after sacrococcygeal teratoma (SCT) resection, and discussed the pathogenesis of sacrococcygeal YST. METHODS: We retrospectively analyzed pediatric SGCT patients attending 10 Japanese institutions. RESULTS: A total of 289 patients were eligible, of which 74.6% were girls. The mean age at surgery was 7.1months. There were 194 mature and 47 immature teratomas, and 48 YSTs. YST developed after SCT resection in 13 patients (5.4% of SCTs), and was detected between 5 and 30months after resection. At initial surgery, 9 of these 13 patients were neonates, 12 underwent gross complete resection with coccygectomy, and 9 had histologically mature teratoma without microscopic YST foci. Postoperative serum alpha-fetoprotein (AFP) levels were regularly examined in 11 patients. Intervals of AFP measurement≤4months helped to detect subclinical localized YSTs for resection. CONCLUSIONS: The characteristics of SGCT in Japanese children were similar with those reported in Europe or the United States. YST developed after SCT resection not only in patients with previously reported risk factors. We recommend that patients undergo serum AFP monitoring every 3months for≥3years after SCT resection.

Adamantinoma-like Ewing family tumor of soft tissue associated with the vagus nerve: a case report and review of the literature.

Adamantinoma-like Ewing family tumor (EFT) is a rare subset of EFTs showing mixed features of Ewing sarcoma and adamantinoma of the long bones. All currently reported cases of the adamantinoma-like type have been associated with bone. Recently, a unique type of EFT was reported showing complex epithelial differentiation associated with the vagus nerve. Here we describe another unique type of EFT arising in the soft tissue of the neck associated with the vagus nerve. An 11-year-old girl presented to our hospital with a neck tumor on her right side. Surgical resection was performed, and histopathologic examination demonstrated a high-grade malignant neoplasm. The tumor was composed of sheets of small round proliferating cells, basaloid tumor nests with marked squamous differentiation, biphasic growth pattern with epithelioid tumor nests, and spindle cell proliferation. Immunohistochemically, the tumor cells showed diffuse expression of CD99 and FLI-1. In addition, small round cells and basaloid/squamoid components were immunoreactive for AE1/AE3, CAM5.2, cytokeratin 5/6, high-molecular weight keratin, p63, and p40 (ΔNp63). Reverse transcription polymerase chain reaction and direct sequencing analysis revealed that the tumor harbored a t(11;22) translocation, involving EWSR1 and FLI-1, which are characteristic of EFTs. According to these findings, our case has characteristics of both a subset of adamantinoma-like EFT and EFT with complex epithelial differentiation. We suggest that EFT with complex epithelial differentiation is in a common spectrum with the adamantinoma-like type and that adamantinoma-like EFTs can arise in soft tissue, leading to difficulty in differential diagnosis with malignant epithelial tumors.

Methylation of the RASSF1A promoter is predictive of poor outcome among patients with Wilms tumor.

BACKGROUND: Wilms tumor (WT) has a survival rate of 90% following multimodality therapy. Nevertheless, there are some groups of patients with event-free survival rates less than 75%. In addition to clinical prognostic factors, loss of heterozygosity at 1p and/or 16q has been used to determine treatment intensity. However, the incidence of this abnormality is low, and new biomarkers are still needed. PROCEDURE: We analyzed methylation status of three tumor suppressor genes; Ras-association domain family 1 protein, isoform A (RASSF1A), DCR2, and CASP8, in 84 WTs using conventional methylation-specific PCR (cMSP), and the results were correlated with outcome. Furthermore, we analyzed the methylation status of RASSF1A by quantitative MSP (qMSP) in 171 WTs, and evaluated clinical and genetic differences between the methylated and unmethylated tumors. RESULTS: RASSF1A was the most frequently methylated gene identified by cMSP, and associated with a poor outcome. Patients with a RASSF1A-methylated tumor had shorter overall and event-free survival periods (P = 0.043 and 0.018, respectively), when a cut-off value of 7% by qMSP was used. The methylation was more frequent in tumors of older children than younger children (P < 0.001), and in advanced-stage tumors than early stage tumors (P = 0.001). However, multivariate analysis could not confirm the prognostic significance of RASSF1A methylation, possibly because of a small number of advanced stage tumors examined. RASSF1A methylation was correlated with LOH at 1p and/or 16q (P = 0.017), but not with WT1 abnormality, suggesting the methylation and LOH to involve the same tumorigenic pathway. CONCLUSIONS: The methylation status of RASSF1A might be a novel biomarker to predict outcome of WT patients.

Different incidences of epigenetic but not genetic abnormalities between Wilms tumors in Japanese and Caucasian children.

Epidemiological studies show that the incidence of Wilms tumor (WT) in East-Asian children is half of that in Caucasian children. Abnormalities of WT1, CTNNB1, WTX, and IGF2 were reported to be involved in Wilms tumorigenesis in Caucasians, although none of the studies simultaneously evaluated the four genes. WTX forms the ß-catenin degradation complex; however, the relationship between WTX abnormality and CTNNB1 mutation was uncertain in WTs. We examined abnormalities of the four genes in 114 Japanese with WTs to clarify the relationship between genetic and epigenetic factors and the incidence of WTs. We found that abnormalities of WTX and CTNNB1 were mutually exclusive, and that although CTNNB1 mutation was frequent in WTs with WT1 abnormality, but rare in WTs without, the incidences of WTX abnormality were similar between WTs with or without WT1 abnormality. These findings were consistent with those reported in Caucasian populations, and indicate multiple roles of WTX abnormality. Abnormalities of WT1, WTX and CTNNB1, and loss of IGF2 imprinting (LOI) were detected in 31.6%, 22.8%, 26.3%, and 21.1% of the 114 WTs, respectively. When we selected 101 sporadic WTs, the incidences of WT1, CTNNB1, or WTX abnormality were generally comparable between the two populations, whereas the incidence of IGF2 LOI was lower in Japanese than that of IGF2 LOI reported in Caucasians (P = 0.04). This is the first comprehensive study of the four genes, and the results supported the hypothesis that the lower incidence of IGF2 LOI contributes to the lower incidence of WTs in Japanese children.

Outcome of hepatoblastomas treated using the Japanese Study Group for Pediatric Liver Tumor (JPLT) protocol-2: report from the JPLT.

BACKGROUND: In the recent years, surgical resection with pre- and/or postoperative chemotherapy has markedly improved the survival rate of hepatoblastoma patients. We herein report the results of patients treated with the current protocol of the Japanese Study Group for Pediatric Liver Tumor, JPLT-2. METHODS: A total of 279 patients with malignant liver tumor were enrolled in JPLT-2. Data from 212 hepatoblastoma cases were analyzed. PRETEXT I patients were treated with primary resection followed by low doses of cisplatin-pirarubicin (tetrahydropyranyl-adriamycin). Otherwise, patients received preoperative cisplatin-pirarubicin (CITA), followed by surgery and postoperative chemotherapy. Ifosfamide, pirarubicin, etoposide, and carboplatin (ITEC) were given as a salvage treatment. High-dose chemotherapy with hematopoietic stem cell transplantation (SCT) was reserved for patients with metastatic diseases. RESULTS: The 5-year overall survival rate (OS) in non-metastatic cases was 100% for PRETEXT I, 87.1% for PRETEXT II, 89.7% for PRETEXT III, and 78.3% for PRETEXT IV. The 5-year OS in metastatic cases was 43.9%. The outcome in non-metastatic PRETEXT IV cases was markedly improved, while the results of metastatic tumors remained poor. CONCLUSIONS: JPLT-2 protocol achieved satisfactory survival among children with non-metastatic hepatoblastoma. New approaches are needed for patients with metastatic diseases.

Extrarenal Wilms tumor in children with unfavorable histology: a case report.

Extrarenal Wilms tumor is extremely rare, and only 25 cases in children have been reported to date in Japan. A 2-year-old girl presented with a large left lower quadrant abdominal mass. Abdominal computed tomography revealed a retroperitoneal tumor located below the left kidney. At laparotomy, the tumor was encapsulated without evidence of metastasis to other abdominal organs. Pathologic diagnosis of the tumor was extrarenal Wilms tumor with diffuse anaplasia. After complete tumor resection, chemotherapy was administered according to the treatment protocol (Regimen I) of the Japan Wilms Tumor Study Group. Cyclophosphamide and etoposide were administered in combination with vincristine and doxorubicin. Two years after treatment, the patient has had no evidence of recurrence.

Genome-wide analysis of allelic imbalances reveals 4q deletions as a poor prognostic factor and MDM4 amplification at 1q32.1 in hepatoblastoma.

In a single-nucleotide polymorphism array-based analysis of 56 hepatoblastoma (HB) tumors, allelic imbalances were detected in 37 tumors (66%). Chromosome gains were found in 1q (28 tumors), 2q (24), 6p (8), 8q (8), 17q (6), and 20pq (10), and losses in 1p (6), 4q (9), and 16q (4). Fine mapping delineated the shortest overlapping region (SOR) of gains at 1q32.1 (1.3 Mb) and 2q24.2-q24.3 (4.8 Mb), and losses at 4q34.3-q35.2 (8.7 Mb) and 4q32.3 (1.6 Mb). Uniparental disomy of 11pter-11p15.4 (IGF2) and loss of 11pter-p14.1 were found in 11 and 2 tumors, respectively. Expression of HTATIP2 (11p15.1) was absent in 9 of 20 tumors. Amplification was identified in four tumors at 1q32.1, where the candidate oncogene MDM4 is located. In the 4q32.3-SRO, ANXA10S, a variant of the candidate tumor suppressor ANXA10, showed no expression in 19 of 24 tumors. Sequence analysis of ANXA10S identified a missense mutation (E36K, c.106G>A) in a HB cell line. Multivariate analysis revealed that both 4q deletion and RASSF1A methylation (relative risks: 4.21 and 7.55, respectively) are independent prognostic factors. Our results indicate that allelic imbalances and gene expression patterns provide possible diagnostic and prognostic markers, as well as therapeutic targets in a subset of HB.

Two candidate tumor suppressor genes, MEOX2 and SOSTDC1, identified in a 7p21 homozygous deletion region in a Wilms tumor.

A SNP-based array analysis of 100 Wilms tumors (WT) from 97 patients identified 7p alterations (hemizygous and homozygous deletions and uniparental disomy) in nine tumors. The homozygous deletion (HD) region of 7p21 found in one tumor partially overlapped with another HD region reported previously, and was narrowed down to a 2.1-Mb region. Based on an expression analysis of 10 genes located in the HD region in 3 WT lines and previous studies on tumorigenic roles of MEOX2 and SOSTDC1, we further analyzed these two genes. Sequencing showed no mutation in MEOX2, but two missense mutations (L50F and Q129L) in SOSTDC1 in four tumors; L50F in two tumors was of germline origin. Expression levels (0, 1+ and 2+) of MEOX2 were lower in four tumors with 7p alterations than in 18 tumors with no 7p alterations (P = 0.017), and those of SOSTDC1 tended to be lower in five tumors with 7p alterations or SOSTDC1 mutation than in 17 tumors with no 7p alterations or SOSTDC1 mutation (P = 0.056). There were no significant differences in clinical characteristics between nine patients with 7p alterations and 88 patients with no 7p alterations; however, there was a difference in the status of IGF2 (uniparental disomy, loss of imprinting, or retention of imprinting) between the two patient groups (P = 0.028). Losses of MEOX2 and SOSTDC1 may accelerate angiogenesis and augment signals in the Wnt pathway, respectively. Both genes may be prime candidates for 7p tumor suppressor genes, which may have a role in the progression of Wilms tumorigenesis.

Outcome of pediatric renal tumor treated using the Japan Wilms Tumor Study-1 (JWiTS-1) protocol: a report from the JWiTS group.

PURPOSE: In 1996, the Japan Wilms Tumor Study (JWiTS) group was founded to elucidate the efficacy and safety of the regimen established by the National Wilms Tumor Study (NWTS) group in the USA, and a multicenter cooperative study (JWiTS-1) was started in Japan. This report reviews the results of JWiTS-1. METHODS: A total of 307 patients with malignant renal tumor were enrolled in the JWiTS-1 study between 1996 and 2005. Central pathological diagnosis and follow-up data were available in 210 cases. The protocol regimens were similar to the NWTS-5 regimens. Clinical stage was classified according to the Japanese Staging System. RESULTS: Five-year overall survival (OS) rate was 91.1% for nephroblastoma, 72.9% for clear cell sarcoma of the kidney (CCSK), and 22.2% for rhabdoid tumor of the kidney (RTK). In the nephroblastoma patients, 5-year OS was 90.5% for stage I disease, 92.2% for stage II, 90.9% for stage III, 86.7% for stage IV, and 78.7% for stage V. CONCLUSIONS: The OS of patients in the JWiTS-1 study were comparable with the results of other multicenter studies in the USA and Europe. The outcome for patients with nephroblastoma and CCSK was fair. In contrast, the cure rate for those with RTK was not satisfactory. New treatment strategies are needed for patients with RTK.

Intractable secretory diarrhea in a Japanese boy with mitochondrial respiratory chain complex I deficiency.

The etiology of secretory diarrhea in early life is often unclear. We report a Japanese boy who survived until 3 years of age, despite intractable diarrhea commencing soon after birth. The fecal sodium content was strikingly high (109 mmol/L [normal range, 27-35 mmol/L]) and the osmotic gap was decreased (15 mOsm/kg), consistent with the findings of congenital sodium diarrhea. We examined the mitochondrial respiratory chain function by blue native polyacrylamide gel electrophoresis (BN-PAGE) in-gel enzyme staining, BN-PAGE western blotting, respiratory chain enzyme activity assay, and immunohistochemistry. Liver respiratory chain complex (Co) I activity was undetectable, while other respiratory chain complex activities were increased (Co II, 138%; Co III, 153%; Co IV, 126% versus respective control activities). Liver BN-PAGE in-gel enzyme staining and western blotting showed an extremely weak complex I band, while immunohistochemistry showed extremely weak staining for the 30-kDa subunit of complex I, but normal staining for the 70-kDa subunit of complex II. The patient was, therefore, diagnosed with complex I deficiency. The overall complex I activity of the jejunum was substantially decreased (63% of the control activity). The immunohistochemistry displayed apparently decreased staining of the 30-kDa complex I subunit, together with a slightly enhanced staining of the 70-kDa complex II subunit in intestinal epithelial cells. These data imply that intestinal epithelial cells are also complex I-deficient in this patient. Complex I deficiency is a novel cause of secretory diarrhea and may act via disrupting the supply of adenosine triphosphate (ATP) needed for the maintenance of ion gradients across membranes.

The methylation status of RASSF1A promoter predicts responsiveness to chemotherapy and eventual cure in hepatoblastoma patients.

Despite the progress of therapy, outcomes of advanced hepatoblastoma patients who are refractory to standard preoperative chemotherapy remain unsatisfactory. To improve the mortality rate, novel prognostic markers are needed for better therapy planning. We examined the methylation status of 13 candidate tumor suppressor genes in 20 hepatoblastoma tumors by conventional methylation-specific PCR (MSP) and found hypermethylation in 3 of the 13 genes. We analyzed the methylation status of these 3 genes (RASSF1A, SOCS1 and CASP8) in 97 tumors and found hypermethylation in 30.9, 33.0 and 15.5%, respectively. Univariate analysis showed that only the methylation status of RASSF1A but not the other 2 genes predicted the outcome, and multivariate analysis showed a weak contribution of RASSF1A methylation to overall survival. Using quantitative MSP, we found RASSF1A methylation in 44.3% of the 97 tumors. CTNNB1 mutation was detected in 67.0% of the 97 tumors. While univariate analysis demonstrated RASSF1A methylation, CTNNB1 mutation and other clinicopathological variables as prognostic factors, multivariate analysis identified RASSF1A methylation (p = 0.043; relative risk 9.39) and the disease stage (p = 0.002; relative risk 7.67) but not CTNNB1 mutation as independent prognostic factors. In survival analysis of 33 patients in stage 3B or 4, patients with unmethylated tumor had better overall survival than those with methylated tumor (p = 0.035). RASSF1A methylation may be a promising molecular-genetic marker to predict the treatment outcome and may be used to stratify patients when clinical trials are carried out.