The histone deacetylase inhibitor, CBHA, inhibits growth of human neuroblastoma xenografts in vivo, alone and synergistically with all-trans retinoic acid.

Histone deacetylase inhibitors (HDACIs) inhibit the growth of a variety of transformed cells in culture. We demonstrated previously that the hybrid-polar HDACI m-carboxycinnamic acid bis-hydroxamide (CBHA) induces apoptosis of human neuroblastoma in vitro and is effective in lower doses when combined with retinoids. The current study investigates the effect of CBHA on the growth of human neuroblastoma in vivo, both alone and in combination with all-trans retinoic acid (atRA), using a severe combined immunodeficiency-mouse xenograft model. CBHA (50, 100, and 200 mg/kg/day) inhibited growth of SMS-KCN-69n tumor xenografts in a dose-dependent fashion, with 200 mg/kg CBHA resulting in a complete suppression of tumor growth. The efficacy of 50 and 100 mg/kg CBHA was enhanced by the addition of 2.5 mg/kg atRA. This dose of atRA was ineffective when administered alone. Treatment was accompanied by mild weight loss in all groups except the lowest dose of CBHA. Our results suggest HDACIs alone or combined with retinoids may have therapeutic utility for neuroblastoma.

Hybrid polar histone deacetylase inhibitor induces apoptosis and CD95/CD95 ligand expression in human neuroblastoma.

Inhibitors of histone deacetylase (HDAC) have been shown to have both apoptotic and differentiating effects on various tumor cells. M-carboxycinnamic acid bishydroxamide (CBHA) is a recently developed hybrid polar compound structurally related to hexamethylene bisacetamide. CBHA is a potent inhibitor of HDAC activity. CBHA induces cellular growth arrest and differentiation in model tumor systems. We undertook an investigation of the effects of CBHA on human neuroblastoma cell lines in vitro. When added to cultures of a panel of neuroblastoma cell lines, CBHA induced the accumulation of acetylated histones H3 and H4, consistent with the inhibition of HDAC. Concentrations of CBHA between 0.5 microM and 4 microM led to apoptosis in nine of nine neuroblastoma cell lines. Apoptosis was assessed by DNA fragmentation analysis and the appearance of a sub-G1 (<2N ploidy) population by flow cytometric analysis. The addition of a caspase inhibitor (benzyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone) completely abrogated CBHA-induced apoptosis in three of three cell lines. The addition of cycloheximide greatly reduced CBHA-induced apoptosis, suggesting that apoptotic induction was dependent on de novo protein synthesis. In addition, CBHA induced the expression of both CD95 (APO-1/Fas) and CD95 ligand within 12 h. The effect of CBHA on human neuroblastoma cells suggests that this agent and structurally related synthetic hybrid polar compounds have therapeutic potential for the treatment of this malignancy.

Very-high-dose short-term chemotherapy for poor-risk peripheral primitive neuroectodermal tumors, including Ewing's sarcoma, in children and young adults.

PURPOSE: To improve the prognosis of patients with poor-risk peripheral primitive neuroectodermal tumors (pPNETs; including peripheral neuroepithelioma and Ewing's sarcoma), while testing the feasibility of intensive use in adolescents and young adults of high-dose cyclophosphamide, doxorubicin, and vincristine (HD-CAV). PATIENTS AND METHODS: This report concerns previously untreated patients with newly diagnosed pPNET deemed poor-risk because of a tumor volume more than 100 cm3 or metastases to bone or bone marrow. The P6 protocol consists of seven courses of chemotherapy. Courses 1, 2, 3, and 6 include 6-hour infusions of cyclophosphamide on days 1 and 2 for a total of 4,200 mg/m2 per course (140 mg/kg per course for patients < 10 years old), plus 72-hour infusions of doxorubicin 75 mg/m2 and vincristine 2.0 mg/m2 beginning on day 1 (HD-CAV). Courses 4, 5, and 7 consist of 1-hour infusions of ifosfamide 1.8 g/m2/d and etoposide (VP-16) 100 mg/m2/d, for 5 days. Granulocyte colony-stimulating factor (G-CSF) and mesna are used. Courses start after neutrophil counts reach 500/microL and platelet counts reach 100,000/uL. Surgical resection follows course 3 and radiotherapy follows completion of all chemotherapy. RESULTS: Among the first 36 consecutive assessable patients (median age, 17 years), HD-CAV achieved excellent histopathologic or clinical responses in 34 patients and partial responses (PRs) in two patients. For 24 patients with locoregional disease, the 2-year event-free survival rate was 77%; adverse events were two locoregional relapses, one distant relapse, and one secondary leukemia. All six patients with metastatic disease limited to lungs achieved a complete response (CR) and did not relapse; one is in remission 36+ months from diagnosis, but the other patients are not assessable in terms of long-term efficacy of the P6 protocol because of short follow-up time (n = 3), additional systemic therapy (bone marrow transplantation), or septic death (autopsy showed no residual pPNET). All six patients with widespread metastases had major responses, including eradication of extensive bone marrow involvement, but distant relapses ensued. Myelosuppression was severe, but most patients received the first three courses of HD-CAV within 6 to 7 weeks. Major nonhematologic toxicities were mucositis and peripheral neuropathy. CONCLUSION: Excellent antitumor efficacy and manageable toxicity support the dose-intensive use of HD-CAV for pPNET in children, as well as in young adults. Consolidation of remissions of pPNET metastatic to bone and bone marrow remains a therapeutic challenge.

Recurrence and morbidity in differentiated thyroid carcinoma in children.

The management of differentiated thyroid cancer in childhood is controversial. In particular, the role of aggressive surgical treatment has been questioned. This study was performed to identify those factors that are predictive of recurrence and morbidity following treatment through use of a multivariate model. The records of all patients 17 years of age or less admitted in the last 35 years with histologically confirmed differentiated thyroid carcinoma were reviewed. Data were sufficient for multivariate analysis in 93. The mean age at diagnosis was 13.3 years, and the median period of follow-up was 20 years. Seventy-one percent of the patients had nodal metastases. There were no deaths from thyroid carcinoma in this series, and the overall recurrence rate after initial treatment was 34%. Multivariate analysis demonstrated that only age (p less than or equal to 0.07) and histologic subtype (p less than or equal to 0.01) were predictive of time to recurrence. Major morbidity was a function of age (p less than or equal to 0.007) and extent of thyroid surgery (p less than or equal to 0.01). Probability of minor complications was predicted by use of radical neck dissection (p less than or equal to 0.02). Use of total or subtotal thyroidectomy or of radical neck dissection in children does not prevent recurrence and is associated with an increased risk of complications. We conclude that these procedures should be avoided in pediatric patients.

Genitourinary tract cancer in childhood.

Tumors of the genitourinary tract are heterogeneous and can be organized according to both site and specific histopathology. This article divides these neoplasms into primary tumor originating from the kidney, adrenal gland, collecting system, urinary bladder, and gonads. Primary renal tumors are further subdivided into Wilms' tumors and rare kidney tumors of childhood including clear cell sarcoma, rhabdoid tumors, mesoblastic nephromas, and renal cell carcinoma, sarcomas, and lymphomas. The rarity and smooth muscle origin of collecting system tumors is noted. Adrenal tumors are divided into cortical and medullary. Cortical neoplasms include adenomas and renal cortical carcinomas; pheochromocytoma and neuroblastoma arise from the adrenal medulla. Bladder and prostate rhabdomyosarcomas most frequently affect these organs and are discussed together. Finally, gonadal neoplasms with emphasis on germ cell tumors of these organs are presented. The multidisciplinary approach and importance of the pediatric surgical oncologist in the management of genitourinary tumors in childhood are emphasized.

Non-Hodgkin's lymphoma of the head and neck in childhood.

Non-Hodgkin's lymphomas (NHL) in childhood account for approximately 10% of solid tumors reported for this age group, and almost 10% of all these lymphomas arise in the head and neck. Most head and neck NHL is a B-cell phenotype (70%) and is characterized by diffuse involvement of anatomic structures. Analysis of the cell surface expression of specific molecules of interest, including immunoglobulins, T-cell receptor components, and antigens specific for immunoblastic cells at discrete points in ontogenic development, has resulted in a greater understanding of the origins and biological behavior of childhood lymphomas. This has significance for the surgeon because specialized studies including immunophenotyping, cytogenetics, and Southern analysis require adequate amounts of tissue that has been properly processed after removal from the patient. In addition, because chemotherapy is the mainstay of lymphoma treatment, the surgical oncologist must avoid the postoperative morbidity inherent in en-bloc resection of other malignancies of the head and neck and thereby facilitate initiation of therapy. This article discusses the clinical presentation, imaging, treatment, and outcome of NHL primary in the head and neck region. Individual characteristics peculiar to specific anatomic sites are reviewed.

Surgical management of neuroblastoma.

Neuroblastoma treatment remains challenging but has been advanced by the establishment of clinical and biological variables that determine prognostic risk. Risk-based therapy currently is the hallmark of neuroblastoma treatment. Initially, stage and age were the prime determinants of survival used in clinical practice. The Shimada histopathologic classification added to the former 2 and biochemical markers like the serum ferritin, lactic dehydrogenase, and neuron-specific enolase also provided information regarding prognosis. The current era of neuroblastoma therapy has been influenced heavily by advances in molecular biology, most notably the identification of the MYCN oncogene and the application of recombinant DNA methods to identification of chromosomal deletions. Current risk assessment includes age, stage, histopathology, and biochemical markers but also analyses performed on DNA extracted from fresh tumors. This places the onus of obtaining an adequate quantity and quality of fresh neuroblastoma tissue directly on the pediatric surgeon who performs the initial biopsy.

The surgical management of metastases in pediatric cancer.

A significant proportion of children presenting with pediatric solid tumors will have disease distant from the primary site at diagnosis while still more will develop metastases. In this article an appropriate role for the surgical oncologist was determined by extracting surgical and survival data from the literature. It is concluded that aggressive pulmonary metastasectomy is indicated in metastatic osteogenic sarcoma but not in most embryonal soft tissue sarcomas. Wilms' tumor pulmonary metastases are probably best treated by chemotherapy and whole-lung irradiation except for very young children with solitary or localized metastases. However, resection of hepatic metastases from Wilms' tumor may result in long-term disease-free survival. Finally, available data support resection of hepatoblastoma metastases to lung. Surgery maintains an important role in the treatment of metastatic disease but surgeons must remain objective in the reporting and interpretation of results.

cDNA subtraction hybridization: a review and an application to neuroblastoma.

Recent advances in molecular biological techniques have increased our capability to distinguish the small differences in gene expression between subpopulations of cells found within specific tissues or tumor isolates. We use subtractive hybridization or subtractive cloning to generate information regarding genes that direct various aspects of mammalian embryonic development. The technique also is used to identify genes with specificity for particular tissues or cell types or those that regulate various processes in the cell. Also, subject to analysis is the aberrant expression of genes involved in tumorigenesis. Another use is analysis of subpopulations of cell types previously identified within individual solid tumors. We used subtractive cloning in the analysis of cell line subpopulations derived from the human pediatric tumor neuroblastoma. This has resulted in the identification of novel genes that may be useful in the study of this disease.

Differentiated and medullary thyroid cancer in childhood and adolescence.

Thyroid cancer is rare in childhood and consists of several different histopathologic groups with widely varying clinical behavior. Major categories include differentiated, medullary, and anaplastic thyroid cancer. Non-Hodgkin's lymphoma and various sarcomas also can arise in the thyroid. This article discusses differentiated and medullary thyroid cancer in childhood and adolescence. Differentiated thyroid carcinoma is divided into three subtypes: papillary, papillary with follicular elements, and follicular. Medullary tumors may occur in isolation but more frequently are associated with one of the multiple endocrine neoplasia syndromes (MEN). A paradoxical observation concerning patients with differentiated thyroid cancer is that 70% to 80% present with regional lymph node involvement, and more than 20% have distant metastases at diagnosis. However, survival rates in series with median follow-ups of 10 to 20 years have been 90% to 100%. These data have implications for the surgical management of pediatric patients with differentiated thyroid cancer. The cellular and genetic factors that underlie this paradoxical behavior are not understood. Management of children with medullary thyroid cancer was revolutionized by the identification of specific mutations in the ret oncogene that predict for multiple endocrine neoplasia syndromes. This has allowed sensitive and specific diagnosis based on analysis of the patient's white blood cells. Because this leads to earlier diagnosis, total thyroidectomy can be performed at a much earlier age than if the increase in serum calcitonin was used to identify C-cell hyperplasia or early carcinoma. At present, genetic testing should be performed at birth in children suspected of having the MEN IIb syndrome and no later than 1 year of age for those with possible MEN IIa. If specific ret gene mutations are noted, total thyroidectomy is recommended as soon as the diagnosis is established. For MEN IIa patients, thyroidectomy probably should be performed before 5 years of age, whereas patients with MEN IIb may require surgery during the first 6 months to 1 year of life.

The lymphomas: an update for surgeons.

Therapy of the lymphomas is predominantly nonoperative, relying on chemotherapy and radiation therapy. In Hodgkin's lymphoma, the role of the surgeon was once large, involving staging laparotomy. At present, chemotherapy is the predominant mode of therapy in patients of all ages, and the therapeutic distinctions centered on the histology of laparotomy specimens no longer exist. The surgeon most often will encounter the patient with lymphoma for biopsy for tissue diagnosis and for institution of long-term venous access. Non-Hodgkin's lymphoma presents with three cellular subtypes in children, and frequently is first seen in the abdomen and mediastinum as a fast-growing diffuse tumor. As a systemic disease, these lymphomas also are nearly always treated systemically by chemotherapy, yet a small number of patients with localized disease may benefit from attempts at tumor extirpation.

131I therapy for pediatric thyroid cancer.

The treatment of differentiated thyroid cancer occurring in children and young adults remains controversial. Because the mortality rate associated with this disease is extremely low and recurrence can develop many years after primary therapy, it is impossible to perform randomized trials that answer therapeutic questions. In previous issues, the topic of thyroid cancer from the surgical perspective has been addressed. Herein the authors discuss the techniques and applicability of radioactive iodine therapy in the treatment of patients with differentiated thyroid cancer. Topics included are indications for treatment as well as short- and long-term complications. A discussion of secondary malignancies is also provided.

Lymphomas of the anterior mediastinum.

Lymphomas are the most common cause of masses in the pediatric mediastinum. More than 50% of children with lymphoblastic lymphoma present with an anterior mediastinal mass, and more than one third of all patients with non-Hodgkin's lymphoma have their primary sites in the mediastinum. Hodgkin's disease also frequently involves this anatomic compartment with approximately two thirds of all pediatric cases manifesting mediastinal adenopathy. Although surgical resection generally is not involved in the primary treatment of these diseases, surgeons often play a key role in obtaining adequate tissue for proper diagnostic analysis. Surgical access to the mediastinum often is required in the acquisition of a specimen.

A comparative analysis of neuroblastic and substrate-adherent human neuroblastoma cell lines.

In human neuroblastoma cell cultures, two phenotypes with differing biological properties have been described: neuroblastic (N) and substrate-adherent (Schwannian or S). In nude mice, N cells are rapidly growing, clonigenic in soft agar, and tumorigenic, whereas S cells are not. The difference in malignant properties between these two cell types and their ability to interconvert in vitro may have clinical relevance. In an attempt to identify genes that may be important in the phenotypic differences and the interconversion, the authors analyzed five representative N and three S cell lines for differential expression of six genes relevant to uncontrolled growth. Beta2-microglobulin was the only gene measured that showed differential expression between the N and S cell lines. This finding supports the theory that beta2-microglobulin and class I MHC expression are markers for differentiation as well as the use of beta2-microglobulin as a differentiation marker in neuroblastoma. The data also suggest that a disregulation of the beta2-microglobulin gene may be partly responsible for the tumorigenicity of the N phenotype.

Fungal sepsis in a patient with duodenal hematoma.

A 4-year-old boy presented with a duodenal hematoma and was admitted for conservative management including nasogastric tube drainage and parenteral nutrition. Within 2 days, the child became fungemic and went on to require urgent laparotomy. This previously undescribed life-threatening complication of duodenal hematoma is discussed in the context of standard treatment of this injury.

Rectal duplications.

Recent experience with two cases of rectal duplication, which had been misdiagnosed as hemorrhoids, or fistula-in-ano with resultant delay in diagnosis, prompted us to review our prior experience with 11 of these unusual cases. Age at presentation ranged from newborn to 18 years (mean, 17 months). The most common presenting sign was a perianal or anal fistula, observed in five children. Two children presenting with fistulae had concomitant infection in the duplication. Other presenting signs included obstruction or prolapse caused by the rectal mass in three patients, rectal bleeding in three, and urinary retention in one. Some children presented with more than one finding. No associated spinal or vertebral anomalies were observed. Total excision was performed using a transanal approach in eight patients, postanal (transcoccygeal) in two, and posterior sagittal in one. Postoperative continence was normal in all patients. These cases illustrate that rectal duplications can be confused with other types of anorectal pathology including hemorrhoids, fistula-in-ano, and perirectal abscess. Total excision performed using a posterior sagittal, transanal, or transcoccygeal approach is curative.

Extended left hepatectomy (left hepatic trisegmentectomy) in childhood.

BACKGROUND/PURPOSE: Extended left hepatectomy, also referred to as left hepatic trisegmentectomy, in which segments II, III, IV, V, and VIII are excised, is rarely performed in children. Experience with 7 such resections is reported to describe the anatomy, technique, indications, and outcomes of the operation. METHODS: The medical records of all pediatric patients treated at our institution over the last 15 years who underwent extended left hepatectomy were reviewed. Demographic information as well as operative, pathological, and follow-up data were analyzed. RESULTS: Seven patients underwent extended left hepatectomy over this period. There were 5 boys and 2 girls ranging in age between 4 months and 9 years with a median age of 3.1 years. Follow-up ranged from 8 months to 5 years with a median of 3.5 years. Diagnoses included hepatoblastoma (HB, n = 3), focal nodular hyperplasia (FNH, n = 1), leiomyosarcoma (LMS, n = 1), hepatocellularcarcinoma (HCC, n = 1), and metastatic neuroblastoma (NB, n = 1). All surgical margins were grossly negative. Median operative blood loss was 13 mL/kg (range, 5 to 32 mL/kg), and mean hospital stay was 9 days (range, 7 to 12 days). No major intra- or postoperative complications were encountered, and there was no perioperative mortality. The 3 HB patients, 1 FNH patient, 1 LMS patient, and 1 NB patient are without evidence of disease, whereas the 1 child with HCC died of recurrent and distant disease. The 6 surviving children have normal hepatic function. CONCLUSION: Although technically challenging and rarely performed, extended resection of the left hepatic lobe is feasible in children and can yield curative results with minimal morbidity.

Establishment and characterization of a novel hepatoblastoma-derived cell line.

Hepatoblastoma is the most common pediatric liver cancer, and complete resection is required for long-term survival. There are few reported hepatoblastoma cell lines available for study. In order to develop in vitro and animal models, the authors isolated an additional cell line (HB1) from a human hepatoblastoma and here report its characteristics in culture. Cells were analyzed for growth rate, clonigenicity, and tumorigenicity, using electron microscopy. Immunocytochemistry and Northern analysis for the expression of specific surface markers and genes of interest were also performed. HB1 cells required fetal calf serum but grew well in culture (population doubling time of 2 days) and had an undifferentiated appearance under electron microscopy. Epidermal growth factor (EGF) and hydrocortisone stimulated growth with or without serum, but not autocrine growth stimulation via the epidermal growth factor receptor was detected. Proteins produced by HB1 cells under normal culture conditions included alpha-fetoprotein, cytokeratins 8 and 18, and lactate dehydrogenase (with an isozyme subunit composition similar to that of liver). HB1 cells showed chronic, high expression of c-myc and Ha-ras oncogenes but no N-myc and apparently normal RB gene expression. This cell line shows characteristics in culture consistent with malignant, hepatic epithelial cells and is apparently EGF dependent. It may provide a model system for the future development of alternative therapies.

Bronchogenic cysts and esophageal duplications: common origins and treatment.

BACKGROUND/PURPOSE: Bronchogenic cysts and esophageal duplications are usually considered as separate foregut malformations. Yet, both are thought to arise from the same embryological event, division of the embryonic foregut, and they share common histological characteristics, often making their clinical differentiation difficult. METHODS: A retrospective review of the cases of 68 children treated at a single institution between 1937 and 1995 was performed. Thirty children were girls (44%) and 38 were boys (56%). Ages ranged from newborn to 24 years. Complete records were available in all children. Fourteen of these 68 children were asymptomatic. RESULTS: Respiratory (54%) or gastrointestinal (13%) symptoms were the most frequent presenting problems. The majority of children were treated by resection of the cyst (52 of 68; 76%), while 9 of 68 (13%) required lobectomy for intraparenchymal lesions. Three children underwent marsupialization, with all of these children requiring additional surgery for recurrent disease. Five children (5 of 68; 7%) had multiple cysts. The mortality rate from this series was 10% (7 of 68). Two deaths were caused by perioperative exsanguination, one related to bleeding from a cyst lined with gastric mucosa with subsequent ulceration and hemorrhage into the esophagus. Two deaths occurred secondary to septic complications, one from an esophageal leak and the other from an intraparenchymal abscess. Two deaths were caused by respiratory failure; one was unrelated (SIDS). The majority of cysts found on histological review were lined by respiratory epithelium or bronchial glands (51 of 68; 75%). Gastrointestinal epithelium was present in cysts of nine children, only two of which were clinically diagnosed as esophageal duplications. Twenty-one cases (21 of 68; 31%) were classified as esophageal duplications based on the intramural location of the cyst, yet 15 of 21 (71%) contained respiratory epithelium, substantiating the hypothesis of the common origin of these lesions. CONCLUSIONS: The histological similarity and anatomic proximity of the "bronchogenic cysts" and the intramural "esophageal duplications" supports their common origin. The possible complications of bleeding, ulceration, infection, and obstruction of the esophagus or airway, should generally lead to prompt resection.

Cardiac tamponade in the pediatric oncology population: treatment by percutaneous catheter drainage.

PURPOSE: The treatment of pericardial effusion resulting in cardiac tamponade has undergone an evolution in recent years, with the use of less invasive drainage methods in selected cases. To determine optimal therapy for pediatric oncology patients with pericardial effusion and tamponade, the authors reviewed their institutional experience with percutaneous catheter drainage. METHODS: Patient records and operative reports were reviewed, and nine patients were identified who met clinical and echocardiographic criteria of cardiac tamponade and were treated with percutaneous pericardial catheter drainage. RESULTS: The median age at time of diagnosis was 14 years (range, 5 months to 19 years), and the male:female ratio was 7:3. Underlying malignancies included acute myeloblastic leukemia in three, acute lymphoblastic leukemia in one, and Hodgkin's disease, B-cell lymphoma, medulloblastoma, desmoplastic small round cell tumor, and rhabdomyosarcoma in one each. EIght patients (89%) were receiving granulocyte colony-stimulating factor (GCSF) during the period when tamponade developed. All patients had a large or moderate-to-large pericardial effusion and right ventricular collapse with hemodynamic compromise on echocardiography, and two patients (22%) also had pericardial thickening. In nine patients, percutaneous catheter drainage was performed intraoperatively and under fluoroscopic or echocardiographic guidance. A median of 300 mL (range, 82 to 500 mL) of fluid was removed from the pericardial sac during the initial drainage, and cytology was positive in one (6%). Complete echocardiographic resolution was observed in eight patients (89%); a small posterior component persisted in one patient but was not significant hemodynamically. The catheters remained in place for a median of 5 days (range, 1 to 35 days) while repeat aspirations were performed. Tamponade resolved in all patients, and one died of overwhelming systemic sepsis. The survival period was 10 to 22 months, and tamponade or the drainage procedure did not contribute to death. Four patients remain alive after 4 month to 7 years of follow-up. CONCLUSION: Cardiac tamponade was effectively treated in all patients and did not recur with percutaneous catheter drainage alone. THere was no evidence of pericardial loculation or infection despite pancytopenia being prevalent with underlying illness and chemotherapy. Percutaneous catheter drainage is an effective treatment for pediatric oncology patients with pericardial tamponade. Because of its simplicity in comparison to move invasive techniques, initial treatment with percutaneous drainage should be considered in this patient population.