Childhood liver tumors in Argentina: Incidence trend and survival by treatment center. A report from the national pediatric cancer registry, ROHA network 2000-2015.

BACKGROUND: Information on the epidemiology of pediatric liver tumors in Latin America is limited. PURPOSE: To describe the incidence of liver tumors in a pediatric registry in Argentina according to geographic region, national trends over 16 years, and survival related to stage, age, sex, and care center. METHODS: Newly diagnosed liver tumors cases are registered in the Argentine Pediatric Oncology Hospital Registry (ROHA) with an estimated coverage of 91% of national cases. Age-standardized incidence rate per millon (ASR) was calculated based on the National Vital Statistics Reports. Five-year overall survival (OS) was estimated using the Kaplan-Meier method. The log-rank test was used to compare subgroup survival. RESULTS: Two hundred seven cases of hepatoblastoma (HB) and 73 of hepatocellular carcinoma (HCC) were identified. ASR of liver tumors was 1.8/million (95% confidence Interval [CI], 1.6-2.0) per year. ASR was 1.4 (1.2-1.6) for HB and 0.4 (0.3-0.5) for HCC. For HB, the highest incidence was found in the northwest region including the Altiplano. OS was 60.4% (53.4-66.8) for HB and 36.1% (25.2-47.2) for HCC. Five-year survival rate of children with metastatic HB treated at liver transplant hospitals (LTH) was 54.2% (30.3-73.0) compared to 13.3% (2.2-34.6) for those seen at other hospitals (OH) (P = .02), while for HCC this rate was 46.3% (30.7-60.6) at LTH compared to 17.5% (3.1-41.9) at OH (P = .01). CONCLUSIONS: The incidence rate of pediatric liver tumors was stable over the 16-year study period. Patients may benefit if at treatment initiation they are evaluated jointly with LTH specialists to define treatment strategies.

Immunoreactivity of the 14F7 Mab raised against N-Glycolyl GM3 Ganglioside in retinoblastoma tumours.

INTRODUCTION: The identification of molecules expressed selectively on the surface of retinoblastoma cells would allow applying targeted therapies. The Ganglioside, N-Glycolyl-GM3 (NeuGc-GM3), is an attractive candidate, as it has been detected in other paediatric neuroectodermic tumours, and it is not expressed in human normal tissues. The 14F7 antibody recognizes specifically the ganglioside NeuGc-GM3. PURPOSE: To characterize the expression of NeuGc-GM3 in retinoblastoma cell lines and in retinoblastoma tumours using the 14F7 monoclonal antibody. METHODS: We studied WERI-Rb1 and Y79 cell lines, 24 retinoblastoma primary tumours from unilateral and bilateral cases and two bone marrow biopsies from metastatic retinoblastoma. Tumours were classified into three groups: non-invasive (n = 13), invasive (n = 9) and metastatic (n = 2). Three eyes enucleated because of non-tumoural conditions were used as controls. Cell lines and tumour sections were studied by immunohistochemistry using the 14F7 antibody. NeuGc-GM3 expression was evaluated by analysing the percentage of positive tumoural cells and the staining intensity. These parameters were analysed comparatively among the three groups. RESULTS: Both retinoblastoma cell lines showed immunoreactivity to NeuGc-GM3 but WERI-Rb1 presented higher intensity than Y79. All the tumours studied showed strong immunoreactivity to NeuGc-GM3 with no significant differences among groups. In both bone marrow specimens, NeuGc-GM3 immunoreactivity was observed in retinoblastoma cells. In bilaterally enucleated cases, NeuGc-GM3 immunoreactivity was not altered before and after chemotherapy. Non-tumoural retinas were negative. CONCLUSIONS: NeuGc-GM3 is highly expressed in retinoblastoma cell lines, tumours and metastatic cells to the bone marrow, and it is not detectable in control eyes. There were no significant differences in the immunoreactivity to 14F7 among tumours from different disease stages. Its immunoreactivity did not change after chemotherapy.

Inflammatory myofibroblastic tumor of the lung in children: anaplastic lymphoma kinase (ALK) expression and clinico-pathological correlation.

The inflammatory myofibroblastic tumor (IMT) is a rare neoplastic lesion with a high incidence in children and young people, and may arise in lungs, soft tissue, or viscera. It is recognized as a borderline tumor with the possibility to recur, undergo malignant transformation, and metastasize. IMT is composed of fascicles of bland myofibroblastic cells admixed with an inflammatory infiltrate consisting of lymphocytes, plasma cells, and eosinophils. We reviewed pulmonary IMT diagnosed at Garrahan Hospital in Buenos Aires, Argentina, during 12 years and examined the clinical, laboratory, and pathological features as well as molecular genetics. Eight pediatric cases were evaluated with a male-to-female ratio of 5:3 and a median age of 6 years at diagnosis. The most common lung localization was the upper lobe. All cases underwent surgical excision and no local recurrences were found. Five out of eight patients, including two cases with metastatic/multifocal lesions in the central nervous system (CNS), are alive and disease free after a median follow-up of 30 months. Anaplastic lymphoma kinase (ALK) expression was negative in all pulmonary samples by immunohistochemistry (IHC), however, rearrangement for ALK locus by fluorescence in situ hybridization was found in one lung and in two CNS samples. These findings may reflect higher sensitivity of the molecular biologic procedure compare to traditional IHC practice. In our pediatric experience, 25% of patients with lung IMT developed CNS lesions; therefore we consider that CNS screening in these patients should be considered, at diagnosis and later during follow up.

Detection of N-glycolyl GM3 ganglioside in neuroectodermal tumors by immunohistochemistry: an attractive vaccine target for aggressive pediatric cancer.

The N-glycolylated ganglioside NeuGc-GM3 has been described in solid tumors such as breast carcinoma, nonsmall cell lung cancer, and melanoma, but is usually not detected in normal human cells. Our aim was to evaluate the presence of NeuGc-GM3 in pediatric neuroectodermal tumors by immunohistochemistry. Twenty-seven archival cases of neuroblastoma and Ewing sarcoma family of tumors (ESFT) were analyzed. Formalin-fixed, paraffin-embedded tumor samples were cut into 5 µm sections. The monoclonal antibody 14F7, a mouse IgG1 that specifically recognizes NeuGc-GM3, and a peroxidase-labeled polymer conjugated to secondary antibodies were used. Presence of NeuGc-GM3 was evident in 23 of 27 cases (85%), with an average of about 70% of positive tumors cells. Immunoreactivity was moderate to intense in most tumors, showing a diffuse cytoplasmic and membranous staining, although cases of ESFT demonstrated a fine granular cytoplasmic pattern. No significant differences were observed between neuroblastoma with and without NMYC oncogene amplification, suggesting that expression of NeuGc-GM3 is preserved in more aggressive cancers. Until now, the expression of N-glycolylated gangliosides in pediatric neuroectodermal tumors has not been investigated. The present study evidenced the expression of NeuGc-GM3 in a high proportion of neuroectodermal tumors, suggesting its potential utility as a specific target of immunotherapy.

Detection and characterization of N-glycolyated gangliosides in Wilms tumor by immunohistochemistry.

Gangliosides are glycolipids present on the cell surface. The N-glycolylated ganglioside NeuGc-GM3 has been described in some neoplasms, such as breast carcinoma and melanoma, but is usually not detected in normal human cells. Our aim was to evaluate the presence of NeuGc-GM3 in Wilms tumor by immunohistochemistry. Postchemotherapy tumors were grouped into different histologic subtypes considering the main preserved component. Formalin-fixed, paraffin-embedded tumor samples were cut into 5-microm sections. The monoclonal antibody 14F7, a mouse IgG1 that specifically recognizes NeuGc-GM3, and a peroxidase-labeled polymer conjugated to secondary antibodies were used. Sections from breast carcinoma were employed as positive controls. Presence of NeuGc-GM3 was evident in 22 of 25 (88%) cases. The staining was stronger in the epithelial component, with a membrane pattern and cytoplasmic diffusion. The stromal component expressed cytoplasmic NeuGc-GM3 in cells with rhabdomyoblastic differentiation. Tubules of adjacent renal tissue were also positive, but no expression of NeuGc-GM3 was detected in nontumoral fetal kidney. Until now, the expression of N-glycolylated gangliosides in pediatric solid tumors has not been investigated. The present study evidenced the expression of NeuGc-GM3 in a high proportion of Wilms tumors, suggesting its potential utility as a specific target of immunotherapy.