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PurposeChemotherapy with alternating vincristine-doxorubicin-cyclophosphamide and ifosfamide-etoposide cycles and primary tumor treatment with surgery and/or radiation therapy constitute the usual approach to localized Ewing sarcoma in North America. We tested whether chemotherapy intensification through interval compression could improve outcome.Patients and methodsThis was a prospective, randomized controlled trial for patients younger than 50 years old with newly diagnosed localized extradural Ewing sarcoma. Patients assigned to standard and intensified treatment were to begin chemotherapy cycles every 21 and 14 days, respectively, provided an absolute neutrophil count greater than 750×10(6)/L and a platelet count greater than 75×10(9)/L. Patients received vincristine (2 mg/m2), doxorubicin (75 mg/m2), and cyclophosphamide (1.2 g/m2) alternating with ifosfamide (9 g/m2) and etoposide (500 mg/m2) for 14 cycles, with filgrastim (5 mg/kg per day; maximum, 300 mg) between cycles. Primary tumor treatment (surgery, radiation, or both) was to begin at week 13 (after four cycles in the standard arm and six cycles in the intensified arm). The primary end point was event-free survival (EFS). The study is registered at ClinicalTrials.gov (identifier: NCT00006734).ResultsFive hundred eighty-seven patients were enrolled and randomly assigned, and 568 patients were eligible, with 284 patients in each regimen. For all cycles, the median cycle interval for standard treatment was 21 days (mean, 22.45 days); for intensified treatment, the median interval was 15 days (mean, 17.29 days). EFS at a median of 5 years was 65% in the standard arm and 73% in the intensified arm (P=.048). The toxicity of the regimens was similar.ConclusionFor localized Ewing sarcoma, chemotherapy administered every 2 weeks is more effective than chemotherapy administered every 3 weeks, with no increase in toxicity.

Microvillus inclusion disease (MVID) is a severe form of congenital diarrhea that arises from inactivating mutations in the gene encoding myosin Vb (MYO5B). We have examined the association of mutations in MYO5B and disruption of microvillar assembly and polarity in enterocytes. Stable MYO5B knockdown (MYO5B-KD) in CaCo2-BBE cells elicited loss of microvilli, alterations in junctional claudins, and disruption of apical and basolateral trafficking; however, no microvillus inclusions were observed in MYO5B-KD cells. Expression of WT MYO5B in MYO5B-KD cells restored microvilli; however, expression of MYO5B-P660L, a MVID-associated mutation found within Navajo populations, did not rescue the MYO5B-KD phenotype but induced formation of microvillus inclusions. Microvilli establishment required interaction between RAB8A and MYO5B, while loss of the interaction between RAB11A and MYO5B induced microvillus inclusions. Using surface biotinylation and dual immunofluorescence staining in MYO5B-KD cells expressing mutant forms of MYO5B, we observed that early microvillus inclusions were positive for the sorting marker SNX18 and derived from apical membrane internalization. In patients with MVID, MYO5B-P660L results in global changes in polarity at the villus tips that could account for deficits in apical absorption, loss of microvilli, aberrant junctions, and losses in transcellular ion transport pathways, likely leading to the MVID clinical phenotype of neonatal secretory diarrhea., Introduction Microvillus inclusion disease (MVID) is a rare neonatal diarrheal disorder of the small intestine that arises mainly in European, Middle Eastern, and Navajo Native American cohorts (1, 2). Recent [...]

Ifosfamide and etoposide combined are effective treatments for Ewing's sarcoma and primitive neuroectodermal tumor of bone, according to a study of 518 patients. These two types of bone cancer had a very poor prognosis until effective chemotherapy became available in the 1970s. Ifosfamide and etoposide can be effective even in patients who do not respond to other chemotherapy drugs.

The Epstein-Barr virus (EBV) may promote the development of smooth-muscle tumors in children whose immune systems are suppressed following organ transplantation. Microscopic analysis and studies of slides of tissue samples of smooth-muscle tumors from three young children revealed unique EBV DNA elements. This finding suggests that the tumors were abnormal outgrowths of a single clone of cells, a characteristic known as neoplasia, and that EBV infection preceded the tumors. The smooth-muscle tumors behaved differently in each of the patients. The first patient did not have symptoms, and the liver tumor did not come back after it was removed. The second patient experienced abdominal pain and several other symptoms, and the third patient's diagnosis was made after an incidental endoscopy examination. Patients 2 and 3 did not respond to antiviral or antineoplastic therapy, and both died. The findings suggest that EBV causes the development of smooth-muscle tumors after transplantation.