A nationwide phase II study of delayed local treatment for children with high-risk neuroblastoma: The Japan Children's Cancer Group Neuroblastoma Committee Trial JN-H-11.

PURPOSE: Survival rates of patients with high-risk neuroblastoma are unacceptable. A time-intensified treatment strategy with delayed local treatment to control systemic diseases has been developed in Japan. We conducted a nationwide, prospective, single-arm clinical trial with delayed local treatment. This study evaluated the safety and efficacy of delayed surgery to increase treatment intensity. PATIENTS AND METHODS: Seventy-five patients with high-risk neuroblastoma were enrolled in this study between May 2011 and September 2015. Delayed local treatment consisted of five courses of induction chemotherapy (cisplatin, pirarubicin, vincristine, and cyclophosphamide) and myeloablative high-dose chemotherapy (melphalan, etoposide, and carboplatin), followed by local tumor extirpation with surgery and irradiation. The primary endpoint was progression-free survival (PFS). The secondary endpoints were overall survival (OS), response rate, adverse events, and surgical complications. RESULTS: Seventy-five patients were enrolled, and 64 were evaluable (stage 3, n = 8; stage 4, n = 56). The estimated 3-year PFS and OS rates (95% confidence interval [CI]) were 44.4% [31.8%-56.3%] and 80.7% [68.5%-88.5%], resspectively. The response rate of INRC after completion of the treatment protocol was 66% (42/64; 95% CI: 53%-77%; 23 CR [complete response], 10 VGPR [very good partial response], and nine PR [partial response]). None of the patients died during the protocol treatment or within 30 days of completion. Grade 4 adverse effects, excluding hematological adverse effects, occurred in 48% of patients [31/64; 95% CI: 36%-61%]. Major Surgical complications were observed in 25% of patients [13/51; 95% CI: 14%-40%]. CONCLUSION: This study indicates that delayed local treatment is feasible and shows promising efficacy, suggesting that this treatment should be considered further in a comparative study of high-risk neuroblastoma.

Correction to: Results of a phase II trial for high-risk neuroblastoma treatment protocol JN-H-07: a report from the Japan Childhood Cancer Group Neuroblastoma Committee (JNBSG).

In the October 2018 issue of International Journal of Clinical Oncology.

Registration-directed phase 1/2 trial of irinotecan for pediatric solid tumors.

BACKGROUND: Although irinotecan hydrochloride (IRI) is a promising chemotherapeutic agent for pediatric solid tumors, its indications had been off-label in the USA, EU and Japan. Therefore, we conducted a phase 1/2 trial of IRI monotherapy in a registration-directed setting. METHODS: Children aged 2-18 years with solid tumors who were either refractory to or relapsed after standard chemotherapy were enrolled. Phase 1 was a conventional dose escalation study to determine the dose-limiting toxicity (DLT) and the recommended dose. IRI was given i.v. on days 1, 2, 3 and 8, 9, 10 in up to eight, 21 day cycles. RESULTS: The starting dose (40 mg/m2 /day) was determined to be the recommended dose because the next higher dose level (45 mg/m2 /day) resulted in two cases of DLT. Seventeen children (11 in phase 1 and six in phase 2) with a refractory solid tumor received IRI. Of the 12 patients treated with 40 mg/m2 /day, seven (58.3%) achieved a stable disease condition for >8 weeks. CONCLUSIONS: The RD of IRI in this treatment schedule was 40 mg/m2 /day. IRI did not cause tumor shrinkage but might help to stabilize refractory pediatric solid tumors. Based on the accumulating evidence from international studies of the efficacy of IRI against refractory pediatric solid tumors, the Japanese regulatory authority approved its use for this indication in 2011.

Results of a phase II trial for high-risk neuroblastoma treatment protocol JN-H-07: a report from the Japan Childhood Cancer Group Neuroblastoma Committee (JNBSG).

BACKGROUND: The Japanese Children's Cancer Group (JCCG) Neuroblastoma Committee (JNBSG) conducted a phase II clinical trial for high-risk neuroblastoma treatment. We report the result of the protocol treatment and associated genomic aberration studies. METHODS: JN-H-07 was a single-arm, late phase II trial for high-risk neuroblastoma treatment with open enrollment from June 2007 to February 2009. Eligible patients underwent five courses of induction chemotherapy followed by high-dose chemotherapy with hematopoietic stem cell rescue. Surgery for the primary tumor was scheduled after three or four courses of induction chemotherapy. Radiotherapy was administered to the primary tumor site and to any bone metastases present at the end of induction chemotherapy. RESULTS: The estimated 3-year progression-free and overall survival rates of the 50 patients enrolled were 36.5 ± 7.0 and 69.5 ± 6.6%, respectively. High-dose chemotherapy caused severe toxicity including three treatment-related deaths. In response to this, the high-dose chemotherapy regimen was modified during the trial by infusing melphalan before administering carboplatin and etoposide. The modified high-dose chemotherapy regimen was less toxic. Univariate analysis revealed that patients younger than 547 days and patients whose tumor showed a whole chromosomal gains / losses pattern had a significantly poor prognosis. Notably, the progression-free survival of cases with MYCN amplification were not inferior to those without MYCN amplification. CONCLUSIONS: The outcome of patients treated with the JN-H-07 protocol showed improvement over the results reported by previous studies conducted in Japan. Molecular and genetic profiling may enable a more precise stratification of the high-risk cohort.

Tailor-made treatment combined with proton beam therapy for children with genitourinary/pelvic rhabdomyosarcoma.

BACKGROUND: Rhabdomyosarcoma (RMS) is one of the most common soft tissue sarcomas among children. Patients who developed genitourinary/pelvic rhabdomyosarcoma (GU/P-RMS) have a higher complication ratio and relatively poorer event free survival, with local therapy being very important. While proton beam therapy (PBT) is expected to reduce co-morbidity, especially for children, this lacks firm evidence and analysis. We analyzed GU/P-RMS children who had undergone multimodal therapy combined with PBT at a single institution. METHOD: We retrospectively reviewed charts of children with GU/P-RMS treated from January 2007 to May 2013 at the University of Tsukuba Hospital who had undergone multimodal therapy with PBT. RESULTS: There were 5 children and their median age at diagnosis was 2.8 years (0.6-4.4 years). Primary sites were the bladder (2) and the prostate (3). All received neo-adjuvant chemotherapy and 3 underwent chemotherapy during PBT (Group Cx). All patients of Group Cx developed leukocytopenia (WBC <1000/µL). The median dose of PBT was 47.7 GyE (41.4-50.4 GyE). All patients survived by their last hospital visit (median, 36 months). CONCLUSIONS: We analyzed multimodal treatment combined with PBT applied for GU/P-RMS. PBT was well tolerated and could be a plausible choice instead of photon therapy for this population.

Enhanced antitumor effect of lower-dose and longer-term CPT-11 treatment in combination with low-dose celecoxib against neuroblastoma xenografts.

BACKGROUND: We have previously reported that the combination of low-dose (5.9 mg/kg/dose) irinotecan (CPT-11) and simultaneous low-dose (5 mg/kg/dose) celecoxib, a cyclooxygenase-2 inhibitor, administered for 20 consecutive days, had synergistic antitumor activity against human neuroblastoma xenografts in mice. Possible further antitumor efficacy of lower-dose and longer-term CPT-11 combined with simultaneous low-dose celecoxib was investigated for chemosensitive TNB9 and multi-drug resistant TS-N-2nu neuroblastoma xenografts. METHODS: The time from initiation of drug treatment to tumor regrowth, tumor doubling time, and body weight change of mice were evaluated between treatments with lower-dose (3 mg/kg/dose) CPT-11 alone and the combination of the two drugs for 60 consecutive days. Induction of apoptosis and autophagy during treatments were analyzed by immunoblotting, real-time quantitative RT-PCR, TUNEL assay, and immunohistochemistry. RESULTS: The combination of the two drugs administered for 60 consecutive days resulted in a significantly longer time to tumor regrowth (p < 0.011) and longer tumor doubling time (p < 0.013) in both xenografts than for the lower-dose CPT-11 therapy alone, without substantial side effects in mice. In particular, five of six TNB9 tumors treated with the combination of the two drugs showed no regrowth even 120 or 150 days after the initiation of therapy. The combined treatment suppressed the induction of autophagy leading to apoptosis in TNB9 tumors, and induced autophagy to enhance the antitumor effect in TS-N-2nu tumors. CONCLUSION: Our findings demonstrate that lower-dose and longer-term CPT-11 treatment in combination with simultaneous low-dose celecoxib enhances antitumor activity and can successfully eradicate most of the neuroblastoma xenografts.

Successful treatment of infants with localized neuroblastoma based on their MYCN status.

BACKGROUND: The aim of this study was to evaluate the effectiveness of post-surgical chemotherapy for infants with localized neuroblastoma without MYCN amplification (MNA), and determine whether risk classification using MNA is reasonable. METHODS: Four hundred and fourteen eligible patients were registered between 1998 and 2004. Resectable patients in stage 1 and 2A/2B were treated by surgical resection only. Unresectable patients in stage 3 without MNA received either 6 cycles of regimen A or 3 cycles of regimen A plus 3 cycles of regimen C2; regimen A consisted of low doses of cyclophosphamide and vincristine and regimen C consisted of cyclophosphamide, vincristine and pirarubicin before surgical resection. The resectable and unresectable patients were randomly selected to receive post-surgical chemotherapy. The patients with MNA received intensive chemotherapy regimen D2, consisting of cyclophosphamide, vincristine, pirarubicin and cisplatin, and some of them received high-dose chemotherapy with stem cell transplantation. RESULTS: The 5-year event-free survival (5-EFS) rates of stage 1 and 2A/2B patients without MNA were 97.2 and 89.0% respectively (p = 0.02). A total of 31 patients in stage 3 without MNA received post-surgical chemotherapy, and 30 patients did not. The 5-EFS rates of these two groups (96.0 and 96.2%, respectively) were not significantly different (p = 0.869). The 5-EFS rate for localized patients with MNA (n = 6) was 50.0%, and that of patients without MNA was 95.0% (p < 0.001). CONCLUSION: Post-surgical chemotherapy was therefore unnecessary for localized patients without MNA. This treatment strategy using MNA is considered to be appropriate in infants.

Guidelines for imaging and staging of neuroblastic tumors: consensus report from the International Neuroblastoma Risk Group Project.

Neuroblastoma is an enigmatic disease entity; some tumors disappear spontaneously without any therapy, while others progress with a fatal outcome despite the implementation of maximal modern therapy. However, strong prognostic factors can accurately predict whether children have "good" or "bad" disease at diagnosis, and the clinical stage is currently the most significant and clinically relevant prognostic factor. Therefore, for an individual patient, proper staging is of paramount importance for risk assessment and selection of optimal treatment. In 2009, the International Neuroblastoma Risk Group (INRG) Project proposed a new staging system designed for tumor staging before any treatment, including surgery. Compared with the focus of the International Neuroblastoma Staging System, which is currently the most used, the focus has now shifted from surgicopathologic findings to imaging findings. The new INRG Staging System includes two stages of localized disease, which are dependent on whether image-defined risk factors (IDRFs) are or are not present. IDRFs are features detected with imaging at the time of diagnosis. The present consensus report was written by the INRG Imaging Committee to optimize imaging and staging and reduce interobserver variability. The rationales for using imaging methods (ultrasonography, magnetic resonance imaging, computed tomography, and scintigraphy), as well as technical guidelines, are described. Definitions of the terms recommended for assessing IDRFs are provided with examples. It is anticipated that the use of standardized nomenclature will contribute substantially to more uniform staging and thereby facilitate comparisons of clinical trials conducted in different parts of the world.

Experimental repair of tracheal defect using a bioabsorbable copolymer.

BACKGROUND: We investigated epithelialization and newly formed cartilage in an artificial trachea constructed using a bioabsorbable copolymer. MATERIALS AND METHODS: Fifteen male Japanese white rabbits (2.5-2.8 kg) were divided into three groups. A full-thickness anterior defect (4 mm x 10 mm) was created in the trachea. The defect was implanted with one of the following bioabsorbable copolymers: caprolactone-lactide copolymer sponge sheet reinforced with poly(glycolic acid) fiber mesh (Cop) (n = 6, group A), Cop-incorporating gelatin hydrogel (n = 4, group B), and Cop-incorporating gelatin hydrogel with 100 microg of basic fibroblast growth factor (n = 5, group C). Each trachea was reinforced with an external nondegradable polymer stent. Three rabbits in each group were sacrificed at 1, 3, and 6 mo postoperatively and the trachea was evaluated histologically; other animals were sacrificed up to 12 mo postoperatively. RESULTS: In groups A, B, and C there were two, one, and one postoperative deaths, respectively. In group A, epithelialization was recognized from 1 mo to 12 mo postoperatively, but no new cartilage was formed during the 12 mo following implantation. In group B, epithelialization was recognized 3 and 6 mo postoperatively, and new cartilage was detected at 6 mo after the operation. In group C, newly formed cartilage and epithelialization were observed 3, 6, and even 12 mo postoperatively. Furthermore, neovascularization was observed in groups B and C. CONCLUSIONS: A bioabsorbable copolymer incorporating gelatin hydrogel induces tracheal epithelialization and formation of cartilage and vessels in tracheal defects, and could be available for clinical use in children.

Closure of the larynx for intractable aspiration in neurologically impaired patients.

We present three patients with intractable aspiration pneumonia in the setting of permanent neurologic impairment, who had received a tracheostomy and showed a juxtaposition of the innominate artery against the trachea. Neurologically impaired patients often show a juxtaposition or compression of the innominate artery against the trachea by chest deformity in the setting of severe scoliosis, which could result in a trachea-innominate artery fistula. For intractable aspiration, laryngotracheal separation is safely performed and effective in controlling aspiration, but is occasionally complicated by trachea-innominate artery fistula. As an alternative procedure, we performed a closure of the larynx in these three cases, using double flaps of the vocal folds and false vocal folds, as a treatment for intractable aspiration. After operation, the patients did well without complication or clinical evidence of recurrent aspiration.

Tracheal defect repair using a PLGA-collagen hybrid scaffold reinforced by a copolymer stent with bFGF-impregnated gelatin hydrogel.

PURPOSE: We studied the regenerated cartilage in tracheal defect repair and compared the bio-materials used versus native trachea using basic fibroblast growth factor (bFGF)-impregnated gelatin hydrogel. MATERIALS AND METHODS: A full-thickness anterior defect was created in the cervical trachea of 15 experimental rabbits. The defect was implanted with a hybrid scaffold of poly(lactic-co-glycolic acid) (PLGA) knitted mesh and collagen sponge. The implanted trachea was reinforced with a copolymer stent of polycaprolactone and poly(lactic acid) coarse fiber mesh. A gelatin hydrogel was used for providing a sustained release of bFGF. The reconstructed tracheas were divided into three groups with wrapped materials; without gelatin hydrogel (control group, n = 5), a gelatin hydrogel with saline (gelatin group, n = 5), and a gelatin hydrogel with 100 microg of bFGF (bFGF group, n = 5). One of the five rabbits in each group at 1 month after operation, one at 3 months, and three at 6 months were killed and the engineered tracheas were evaluated histologically. Biomechanical properties were evaluated on samples at 6 months postoperatively. RESULTS: The rigid support in the defect portion was maintained during 6 months postoperatively. The newly regenerated cartilages were recognized between the host cartilage stumps at 3 months postoperatively in the bFGF group, and limited new cartilage growth and epithelialization were observed at 6 months postoperatively. CONCLUSIONS: The experiment shows that using bFGF, better mechanical strength was obtained but with poor cartilage growth.

Neural differentiation potential of rat amniotic epithelial cells.

Amniotic epithelial cells (AEC) are thought to represent a stem-like cell population and to be an attractive cell source for regenerative medicine, because abundant cells can be obtained noninvasively at delivery. The authors investigated the neural differentiation potential of rat AEC. Rat AEC expressed vimentin and nestin, but not c-kit, oct-4, or nanog. The expression of the neural lineage markers, including betaIII-tubulin, neuron specific enolase (NSE), neurofilament-M, neuroD, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP), tyrosine hydroxylase (TH), acetylcholinesterase (AChE), cholin acetyltransferase (ChAT), and mammalian achaete-scute homolog1 (MASH1), was detected by RT-PCR in the cultured rat AEC. After neural induction, rat AEC dramatically changed their shapes, projecting dendrite-like structures. Immunocytochemically, approximately 20% of the induced cells expressed an immature neuronal marker, betaIII-tubulin. Our findings suggested that rat AEC might be already committed to differentiate to various neural lineages and that they could differentiate to immature neurons in vitro.

Prolonged low-dose administration of the cyclooxygenase-2 inhibitor celecoxib enhances the antitumor activity of irinotecan against neuroblastoma xenografts.

Cyclooxygenase (COX)-2 is overexpressed in many human tumors including neuroblastoma (NB) and promotes tumor progression. We evaluated the antitumor effect of irinotecan (CPT-11) treatment combined with prolonged very low-dose administration of celecoxib, a selective COX-2 inhibitor, against three human NB xenografts, TNB9, TS-N-2nu, and TS-N-5nu. In addition, the effects of the celecoxib-combined treatment were examined on tumor cell proliferation, apoptosis, angiogenesis, and expression of vascular endothelial growth factor and apoptosis-related proteins in xenografts. Celecoxib administered daily at 5 mg/kg body weight/day could not prevent the growth of any of the NB xenografts. However, the combination of daily low-dose CPT-11 (5.9 mg/kg body weight/day) and simultaneous very low-dose celecoxib resulted in highly significant suppression of tumor growth in all three xenografts (P < 0.001) compared not only with low-dose CPT-11 therapy alone but also with the combination therapy of intermittent conventional-dose CPT-11 (59 mg/kg body weight) and celecoxib accompanied by decreased proliferation and increased induction of apoptosis in tumor cells. Induction of apoptosis by CPT-11 with and without celecoxib was associated with the up-regulation of Bax expression and the down-regulation of Bcl-2 expression. The enhanced antitumor effect of the combination of the two drugs against the NB xenografts might be partially COX-2-independent and was probably mediated through multiple factors including diminished expression of VEGF and activation of the caspase-dependent mitochondrial apoptosis pathway. These findings demonstrate that prolonged low-dose CPT-11 treatment combined with very low-dose celecoxib shows promising antitumor activity through the blockage of multiple critical targets related to NB tumor cell survival and proliferation.

Myoblast transplantation to defecation muscles in a rat model: a possible treatment strategy for fecal incontinence after the repair of imperforate anus.

PURPOSE: Infants with higher anorectal anomalies often develop fecal incontinence after surgical reconstruction mainly due to the incomplete development of defecation muscles. We investigated the possibility of defecation muscle regeneration by myoblast transplantation to improve fecal continence. METHODS: Myoblasts from F344 female rats at ages of 1 day, 1, 2, 3, 4, 8, and 12 weeks were prepared by a preplating method. In vivo muscle differentiation of myoblasts was evaluated using immunofluorescence after transplantation of GFP-positive myoblasts into nude mice, the damaged thigh muscles, and the levator ani muscle of GFP-negative rats. RESULTS: The ratios of myoblasts obtained from 1 day, 1, 2, 3, 4, 8, and 12-week-old rats were 35, 71, 65, 61, 52, 44, and 23%, respectively. Myotube formation by transplanted myoblasts was observed in the back of nude mice. Myoblasts transplanted into damaged thigh muscles were integrated into recipient muscles with myofiber formation. Transferred myoblasts formed myotubes surrounding the levator ani muscle, although myofiber formation was not observed. CONCLUSION: Myoblasts were most efficiently obtained from juvenile rats. Myoblast transplantation may provide a novel treatment strategy for improving fecal continence after repair of anorectal anomalies in infants.

[Late effects of cancer treatment in children--problems to be solved in adult].

As the number of childhood cancer survivors continues to increase, the problems of late effects following treatment have become a serious issue. At present, the length of follow-up for late effects of treatment largely depends on the individual treating physicians, and no follow-up teams are organized in most of Japan. Childhood cancer survivors may not only have physical handicaps but also experience psychological and social problems. The establishment of a follow-up system is a serious need in Japan and should involve physicians, other medical professionals, social workers, and cancer survivors themselves. Physicians should always consider whether the recommended treatment or surgery will yield the best results from the viewpoint of probable late effects.

Vascular endothelial growth factor expression is closely related to irinotecan-mediated inhibition of tumor growth and angiogenesis in neuroblastoma xenografts.

In the present study, irinotecan (CPT-11) was highly effective not only against the chemosensitive neuroblastoma (NB) xenografts SK-N-ASnu and TNB9, but also against the multidrug-resistant NB xenograft TS-N-2nu. SK-N-ASnu and TNB9 were significantly more responsive to low-dose daily CPT-11 treatment than to intermittent administration of one-third of the median lethal dose. For TS-N-2nu, there was no significant difference in tumor growth inhibition between the two treatment schedules. Treatment with CPT-11 alone could not completely abolish tumor growth in mice. For TNB9, tumor regrowth seemed to result from an inability to regress host vessels in the stroma during treatment and an inability to suppress host-derived vascular endothelial growth factor (VEGF) expression throughout therapy. In the multidrug-resistant TS-N-2nu, VEGF was not suppressed by low-dose therapy with CPT-11, and neurofilament-positive tumor cells escaped from apoptosis and were growth arrested at G(0)/G(1) phase. These findings suggest a mechanism for the incomplete responsiveness of TS-N-2nu to CPT-11. Our data demonstrate that diminished VEGF gene and protein expression is closely correlated with tumor growth inhibition and inhibition of angiogenesis by CPT-11 in NB xenografts. Our results further suggest that a persistent blocker of stroma-derived VEGF will need to be combined with CPT-11 to completely inhibit the growth of chemosensitive NB, and that administration of CPT-11 at higher doses will be required to inhibit the growth of multidrug-resistant NB.

Relationship of DDX1 and NAG gene amplification/overexpression to the prognosis of patients with MYCN-amplified neuroblastoma.

PURPOSE: Amplification of the MYCN gene strongly correlates with advanced stage, rapid tumor progression and poor prognosis in neuroblastoma (NB). Several genes in the MYCN amplicon, including the DEAD box polypeptide 1 (DDX1) gene, and neuroblastoma-amplified gene (NAG gene), have been found to be frequently co-amplified with MYCN in NB. The aim of this study was to clarify the prognostic significance of the co-amplification or overexpression of DDX1 and NAG with MYCN. PROCEDURE: The gene copy numbers and mRNA expression levels of MYCN, DDX1, and NAG in 113 primary NBs were determined by the real-time quantitative polymerase chain reaction or quantitative reverse transcriptase/polymerase chain reaction assay. The relationships between gene co-amplification/overexpression status and stage, age at diagnosis, and overall survival were analyzed. RESULTS: For evaluating the frequency of DDX1 and NAG co-amplification, it proved appropriate to discriminate NBs with <40 copies of MYCN amplification from those with > or =40 copies of MYCN (DDX1, p = 0.00058; NAG, p = 0.0242, chi(2) for independence test). In patients with MYCN-amplified NB aged > or =18 months, those with tumor with enhanced DDX1 expression and low-NAG expression showed a significantly better outcome than those with low-DDX1 expression or enhanced NAG expression (p = 0.0245, log-rank test). None of the gene expression statuses had a significant relation to disease stage or survival for patients <18 months old. No relationship between any gene co-amplification status and disease stage, age at diagnosis, or overall survival was found. CONCLUSIONS: Our findings suggest that there may be a subset of NB in which enhanced DDX1 and low-NAG expression consequent to DDX1 co-amplification without NAG amplification contributes to susceptibility to intensive therapy. A larger study using an age cut-off of 18 months will be required.

Reciprocal expression of CCAAT/enhancer binding proteins alpha and beta in hepatoblastomas and its prognostic significance.

Hepatoblastoma is one of the common pediatric solid tumors with frequent mutation of the beta-catenin gene which might be an early event of its carcinogenesis. However, the detailed molecular mechanism is still unknown. We studied the expression levels of CCAAT/enhancer binding protein alpha (C/EBPalpha) and C/EBPbeta, which regulate differentiation and growth of embryonic hepatocytes, to establish whether or not they were involved in affecting the clinical behavior of hepatoblastoma. The quantitative real-time reverse transcriptase-PCR revealed that expression of C/EBPalpha mRNA was significantly up-regulated in tumors 223% (p=0.013) as compared with that in adjacent normal livers, while expression of C/EBPbeta was down-regulated to 27% (p=0.002). Of interest, the immunohistochemical analysis showed that expression of C/EBPalpha was higher and that of C/EBPbeta lower in the poorly differentiated tumor cells than in the well-differentiated cells within the same tumor. Furthermore, high expression of C/EBPalpha (p=0.047) as well as low expression of C/EBPbeta (p=0.025) was significantly associated with poor prognosis of the patients. Cox hazard model suggested that expression of C/EBPalpha and that of C/EBPbeta were independent indicators to predict the prognosis from age but not from histology. Thus, expression of C/EBP proteins may play an important role in the genesis and clinical behavior of hepatoblastoma probably by inducing different stages of arrest of differentiation.