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R B Womer

Publications and source records attributed to R B Womer.

At least 19 recordsLinked to original sources
PubMed2001

Proliferative and apoptotic differences between alveolar rhabdomyosarcoma subtypes: a comparative study of tumors containing PAX3-FKHR or PAX7-FKHR gene fusions.

BACKGROUND: Most alveolar rhabdomyosarcomas (ARMS) have chromosome translocations and resultant gene fusion products. The more common translocation fuses the PAX3 and FKHR genes; patients who have PAX3-FKHR-positive ARMS have reduced event-free survival compared to patients with ARMS containing the less common translocation that fuses the PAX7 and FKHR genes. PROCEDURE: We examined histology, immunohistochemical markers of differentiation, and cell cycle characteristics of a panel of ARMS containing either PAX3-FKHR or PAX7-FKHR transcript to determine if these features differ between the ARMS subsets. RESULTS: Cell cycle parameters varied significantly: the number of nuclei that stained with either an immunohistochemical marker of proliferation (MIB1), or a TUNEL-based assay for apoptosis was significantly greater in tumors that expressed PAX3-FKHR compared to tumors that expressed PAX7-FKHR transcript. CONCLUSIONS: We conclude that compared to PAX7-FKHR-containing tumors, ARMS that contain PAX3-FKHR transcript have (1) increased cell proliferation, consistent with greater loss of cell cycle regulation, and (2) apoptosis that is increased but insufficient to prevent tumor formation. More marked cell cycle dysregulation may contribute to poorer prognosis for patients with ARMS that have PAX3-FKHR fusion. Med Pediatr Oncol 2001;37:83-89.

Apoptosis↗
PubMed2000

Preoperative staging, prognostic factors, and outcome for extremity rhabdomyosarcoma: a preliminary report from the Intergroup Rhabdomyosarcoma Study IV (1991-1997).

BACKGROUND: During the fourth Intergroup Rhabdomyosarcoma (RMS) Study (IRS IV, 1991-97), a preoperative staging system was evaluated prospectively for the first time. The authors evaluated this staging system and the role of surgery in extremity RMS in contemporary multimodal therapy. METHODS: A total of 139 patients (71 girls; median age, 6 years) were entered in IRS IV with extremity-site RMS. Stage was assigned by the IRSG Preoperative Staging System. Postsurgical group was determined by tumor status after initial surgical intervention. Multivariate analysis was performed using all pretreatment factors that were significant by univariate analysis, including clinical Group (i.e., I through IV), tumor invasiveness (T1,T2), nodal status (N0,N1), and tumor size (< or > or =5 cm). Failure-free survival rates (FFS) and survival rates were estimated using the Kaplan and Meier method. RESULTS: Preoperative staging and clinical group distribution were as follows: Stage 2, n = 34; Stage 3, n = 73; Stage 4, n = 32; Group I, n = 31; Group II, n = 21; Group III, n = 54; Group IV, n = 33. Three-year FFS was 55%, and the overall survival rate was 70%. Eighty-seven patients had either unresectable, gross residual disease (Group III) or metastases (Group IV). FFS was significantly worse for these patients with advanced disease, compared with that for patients with complete resection or with only microscopic residual tumor (i.e., Group I or II; Group I, 3-year FFS, 91%; Group II, 72%; Group III, 50%; Group IV, 23%; P<.001). Lymph nodes were evaluated surgically in 76 patients with positive results in 38. Clinically, 13 additional patients had nodal disease. Both stage and group were highly predictive of outcome and were highly correlated. By multivariate analysis, none of the other variables were predictors of FFS. CONCLUSIONS: This review confirms the utility of pretreatment staging for stratification of patients with extremity RMS with widely different risks of relapse, thereby paving the way for development of risk-based therapy. Group (operative staging) remains the most important predictor of FFS, emphasizing the importance of complete gross resection at initial surgical intervention, when feasible without loss of limb function. The high incidence of nodal disease in the patients who had lymph node biopsy confirms the need for surgical evaluation of lymph nodes to ensure accurate staging in children with extremity rhabdomyosarcoma.

Child↗
PubMed2000

Granulocyte colony stimulating factor permits dose intensification by interval compression in the treatment of Ewing's sarcomas and soft tissue sarcomas in children.

71 children with sarcomas were treated in a prospective pilot study to determine whether granulocyte colony stimulating factor (G-CSF) permits compression of the interval between chemotherapy cycles. Patients had Ewing's sarcoma/primitive neuroectodermal tumour (PNET), rhabdomyosarcoma, non-rhabdo soft tissue sarcomas or other advanced soft tissue tumours. The chemotherapy alternated vincristine-doxorubicin-cyclophosphamide and ifosfamide-etoposide, with G-CSF between courses. Therapy had two phases: induction (six cycles) and continuation (six cycles), which included primary tumour treatment with surgery and/or radiation. Chemotherapy cycles began every 14 days, or upon absolute neutrophil count (ANC) and platelet count recovery. The median chemotherapy cycle interval was 16 (11-48) days in the induction phase, with a median average relative dose intensification (ARDI) of 1.27 compared with every-21-day therapy. In the continuation phase, the median cycle interval was 21 days, with a median ARDI of 1.10. Radiation therapy prolonged chemotherapy intervals, whilst erythropoietin shortened them. Toxicity was modest for such chemotherapy. Event-free survival is comparable with or superior to that in recent large studies. G-CSF permits intensification of this regimen through interval compression. The impact of this approach on efficacy remains to be determined in a randomised trial.

Adolescent↗
PubMed2000

Rhabdomyosarcoma and soft tissue sarcoma in childhood.

The past year has seen a greater understanding of the means by which the alveolar rhabdomyosarcoma gene fusions (PAX-FKHR) lead to the malignant phenotype. The treatment of the primary tumor in rhabdomyosarcoma has been reexamined, with the roles of surgery and radiation expanding in American studies and decreasing in European ones. "Megatherapy" approaches with stem cell or bone marrow autologous transplants still have not found a role in the treatment of metastatic rhabdomyosarcoma. Our understanding of the natural history of nonrhabdo soft tissue sarcomas in children has increased, and molecular diagnosis is becoming established. The role of chemotherapy in treatment remains controversial.

Child↗
PubMed1999

Survival after relapse in children and adolescents with rhabdomyosarcoma: A report from the Intergroup Rhabdomyosarcoma Study Group.

BACKGROUND: Despite advances in therapy, nearly 30% of children with rhabdomyosarcoma experience progressive or relapsed disease, which is often fatal. PATIENTS AND METHODS: To facilitate the development of a retrieval therapy protocol, we studied potential risk factors that were predictive of survival after first relapse in 605 children who were enrolled onto three consecutive Intergroup Rhabdomyosarcoma Study Group protocols. RESULTS: The median survival time from first recurrence was 0.8 years; the estimated percentage of patients who survived 5 years from first recurrence was 17% +/- 2% (mean +/- SD). Univariate analysis showed that tumor histology was an important predictor of 5-year survival (P <.001): the 5-year survival rate was 64% for patients with botryoid tumors (n = 19), 26% for patients with embryonal tumors (n = 313), and 5% for patients with alveolar or undifferentiated sarcoma (n = 273). Further analysis identified prognostic factors within histologic subtypes (P <.001). For patients with embryonal tumors, the estimated 5-year survival rate was 52% for patients who initially presented with stage 1 or group I disease, 20% for those with stage 2/3 or group II/III disease, and 12% for those with group IV disease. For patients with stage 1/group I disease, estimated 5-year survival rates were higher for patients with local (72%) or regional (50%) recurrence than for those with distant (30%) recurrence. Among patients with alveolar or undifferentiated sarcoma, only the disease group predicted outcome: the 5-year survival estimate was 40% for group I versus 3% for groups II through IV. We identified a "favorable risk" group (approximately 20% of patients) whose 5-year estimated survival rate was near 50%; for all other patients, the estimated survival was near 10%. CONCLUSION: This analysis demonstrates that the probability of 5-year survival after relapse for rhabdomyosarcoma is dependent on several factors at the time of initial diagnosis, including histologic subtype, disease group, and stage. These findings will form the basis of a multi-institutional risk-adapted relapse protocol for childhood rhabdomyosarcoma.

Adolescent↗
PubMed1999

EWS-FLI1 and EWS-ERG gene fusions are associated with similar clinical phenotypes in Ewing's sarcoma.

PURPOSE: There are a variety of solid tumors in which alternative chromosomal translocations generate related fusion products. In alveolar rhabdomyosarcoma and synovial sarcoma, these variant fusions have been found to have major clinical significance. We investigated whether the two alternative gene fusion products, EWS-FLI1 and EWS-ERG, define different clinical subsets within the Ewing's sarcoma family of tumors. PATIENTS AND METHODS: We selected 30 cases of Ewing's sarcoma with the EWS-ERG gene fusion and 106 cases with the EWS-FLI1 fusion. Clinical data were obtained for each case and compared with the molecular diagnostic findings. RESULTS: There were no significant clinical differences observed between the two groups in age of diagnosis, sex, metastasis at diagnosis, primary site, event-free survival, or overall survival. CONCLUSION: Differences in the C-terminal partner in the Ewing's sarcoma family gene fusions are not associated with significant phenotypic differences.

Adolescent↗
PubMed1997

Soft tissue sarcomas.

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Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

Common and variant gene fusions predict distinct clinical phenotypes in rhabdomyosarcoma.

PURPOSE: We evaluated the clinical features of the common PAX3-FKHR and variant PAX7-FKHR gene fusions observed in rhabdomyosarcoma. PATIENTS AND METHODS: Reverse-transcriptase polymerase chain reaction (RT-PCR) assays were used to detect the gene fusions in 34 cases of rhabdomyosarcoma. Clinical data were obtained retrospectively and compared with the molecular results. RESULTS: The PAX3-FKHR and PAX7-FKHR gene fusions were present in tumors from 18 and 16 patients, respectively. The group with a PAX7-FKHR fusion was younger (P = .01) and presented more often with an extremity lesion (82% v 22%; P = .001). PAX7-FKHR tumors were more often localized than PAX3-FKHR tumors (P = .03). In patients with metastatic disease at diagnosis, the patterns were different: PAX7-FKHR patients had metastatic disease that involved only bone (n = 2) and distant nodes (n = 2), while the PAX3-FKHR group had multiple sites involved, including bone (n = 7), marrow (n = 7), lungs (n = 3), distant nodes (n = 2), skin (n = 1), and brain (n = 1). No significant difference in relapse rate was observed. A trend toward improved overall survival in the PAX7-FKHR group was noted (P = .09). Event-free survival for this PAX7-FKHR group was significantly longer (P = .04). CONCLUSION: Our results suggest that the common PAX3-FKHR and the variant PAX7-FKHR fusions are associated with distinct clinical phenotypes. Identification of fusion gene status may be a useful diagnostic tool in rhabdomyosarcoma.

Adolescent↗
PubMed1996

Minimal disease detection in patients with alveolar rhabdomyosarcoma using a reverse transcriptase-polymerase chain reaction method.

BACKGROUND: Polymerase chain reaction (PCR) assays that detect fusion genes resulting from consistent chromosomal translocations have been used to detect minimal residual disease, primarily in hematologic malignancies. Molecular assays have been developed recently that detect the PAX3-FKHR or PAX7-FKHR fusion transcript resulting from the t(2; 13) or t(1; 13) translocation consistently observed in alveolar rhabdomyosarcoma. Because of the tumor's propensity to disseminate widely, our aim was to determine whether or not reverse transcriptase-PCR assays could detect submicroscopic disease in bone marrow or peripheral blood specimens. METHODS: We analyzed 19 bone marrow samples from 11 patients with a known gene fusion in their primary tumor. Specimens were collected at diagnosis, remission, and relapse. Fourteen peripheral blood samples were obtained serially from 5 of these patients. A reverse transcriptase-PCR assay was used to detect the presence of the PAX3-FKHR or PAX7-FKHR fusion transcript. These results were compared with the results of microscopic examination of the bone marrow. Medical records of all 11 patients were reviewed. RESULTS: Adequate amplifiable RNA was obtained in 17 of 19 marrow samples. The PCR assay detected fusion products in all 4 specimens obtained from 3 patients with histologic evidence of bone marrow involvement. In addition, PAX3-FKHR fusion products were detected in bone marrows from 2 patients for whom there was no histologic evidence of disease. The fusion transcripts were not detected in any of the peripheral blood samples. CONCLUSIONS: The detection of submicroscopic disease is possible in alveolar rhabdomyosarcoma patients using PCR. These assays may have a role in staging, monitoring therapy, purging protocols for autologous bone marrow transplantation, and post therapy follow-up. Larger prospective studies are needed to address the clinical relevance of these results.

Bone Marrow↗
PubMed1996

Problems and controversies in the management of childhood sarcomas.

Multidisciplinary care and advances in chemotherapy have dramatically improved the prognosis of paediatric sarcoma patients, but much work remains. There are new techniques for molecular diagnosis of Ewing's sarcomas and alveolar rhabdomyosarcomas, with molecular techniques of staging and subclassification under development. Osteosarcoma is a clinically heterogeneous disease which continues to resist biologic diagnosis, classification, or staging. In chemotherapy, the roles of ifosfamide and doxorubicin in rhabdomyosarcoma treatment remain unclear. While many children with metastatic or recurrent sarcomas undergo massive therapy with peripheral stem cell or autologous marrow rescue, the efficacy of these manoeuvres is debatable. Osteosarcoma appears to respond best to regimens containing doxorubicin and cisplatin, while the roles of alkylating agents, high-dose methotrexate, and carboplatin remain unclear. Ewing's sarcoma treatment increasingly includes surgery because of the risk of secondary osteosarcoma after radiation. Most osteosarcoma patients now have limb-sparing excisions, though amputation may provide better function and cosmesis with less risk of complications in some patients. The role of multimodal treatment including chemotherapy for the miscellaneous soft tissue sarcomas remains uncertain.

Amputation, Surgical↗
PubMed1995

Molecular assays for chromosomal translocations in the diagnosis of pediatric soft tissue sarcomas.

OBJECTIVE: To compare molecular assays for characteristic chromosomal translocations with standard histopathologic and cytogenetic analysis in the differential diagnosis of pediatric soft tissue sarcomas. DESIGN: Blinded comparison with histopathologic diagnosis. SETTING: Tertiary care children's hospital. PATIENTS: A total of 79 soft tissue sarcoma patients with frozen tumor tissue and histopathologic slides available for review. METHODS: The RNA from the tumors was assayed by the reverse transcriptase-polymerase chain reaction. These assays detect PAX3-FKHR and PAX7-FKHR chimeric transcripts in alveolar rhabdomyosarcoma, EWS-FLI1 and EWS-ERG chimeric transcripts in Ewing's sarcoma, and EWS-WT1 chimeric transcripts in desmoplastic small round cell tumor. MAIN OUTCOME MEASURES: The polymerase chain reaction findings were compared with cytogenetic and histopathologic results. RESULTS: These assays detected chimeric transcripts in all cases in which translocations were found by standard cytogenetics as well as additional cases without cytogenetically detectable translocations. PAX3-FKHR or PAX7-FKHR fusions were present in 18 of 21 alveolar rhabdomyosarcomas, two of 30 embryonal rhabdomyosarcomas, and one of seven undifferentiated sarcomas. EWS-FLI1 or EWS-ERG fusions were detected in six of eight Ewing's sarcomas and one of seven undifferentiated sarcomas. The EWS-WT1 fusion was found in three of three desmoplastic small round cell tumors. CONCLUSIONS: Molecular assays for specific gene fusions provide a genetic approach to the differential diagnosis of soft tissue sarcomas. The genetic categories correspond closely to the standard histopathologic categories. The polymerase chain reaction assays for chimeric transcripts are useful tools for the rapid and objective assessment of pediatric soft tissue sarcomas.

Base Sequence↗
PubMed1995

Oral methotrexate and alternate-day prednisone for low-risk Langerhans cell histiocytosis.

Many treatments for low-risk Langerhans cell histiocytosis (LCH) involve unpleasant side-effects or risks of late effects. To provide treatment with minimal toxicity and no known risk of late effects, we have used oral alternate-day prednisone (PDN, 40 mg/sq.m./day) and weekly methotrexate (MTX, 20 mg/sq.m. once weekly) in a series of 13 children with 17 episodes of LCH. Patients were monitored with monthly physical examinations, blood counts and chemistry panels, and radiographs and scans obtained at the treating physician's discretion. Patients who responded had the prednisone tapered and MTX discontinued after three months of treatment. Recurrences while treatment was being tapered, or after its discontinuation, were managed with resumption of MTX and PDN. Treatment was successful in 16 of the 17 episodes, meaning that symptoms resolved and abnormal physical or radiographic findings improved. Symptomatic relief occurred in two weeks or less in 14 of 17 episodes; objective improvement generally occurred within one month, and in all cases by three months. The median duration of treatment was 5 months. Toxicity was limited to slight, transient elevations in hepatic enzymes in three patients. We conclude that oral chemotherapy with alternate-day PDN and weekly MTX is effective and non-toxic in patients with low-risk LCH.

Child↗
PubMed1995

Langerhans cell histiocytosis: presentation and evolution of radiologic findings with clinical correlation.

Radiologic images and medical records of 42 children with Langerhans cell histiocytosis (LCH) (histiocytosis X) were reviewed to evaluate the presentation of the disease and the evolution of the radiologic findings. There were 26 male and 16 female patients aged 3 months to 18 years. Twenty-two patients presented with localized disease; 20 presented with multifocal disease. Four patients developed diabetes insipidus. Two patients had organ dysfunction. The radiologic findings were largely due to destructive bone lesions; 83% of the patients had at least one affected bone. Isolated soft-tissue masses, interstitial lung disease, and central nervous system abnormalities were also seen. Of patients in whom results of appropriate follow-up were available, 91% showed improvement in their lesions, 43% developed new lesions, and 92% had good clinical outcomes. LCH is usually a self-limited disease with a varied clinical and radiologic presentation. The prognosis is generally poor in children with organ dysfunction. In the absence of organ dysfunction, children with either localized or multifocal LCH have an excellent prognosis.

Adolescent↗
PubMed1994

Primary intraspinal soft-tissue sarcoma in childhood: report of two cases with a review of the literature.

Two young children who presented with lower spinal cord dysfunction manifested by bilateral leg weakness and urinary retention were diagnosed with intraspinal soft-tissue sarcoma. Neither patient had a significant extradural mass. Both tumors had histochemical features of rhabdomyosarcoma. Temporary responses were noted after combination chemotherapy either with vincristine, actinomycin D, and cyclophosphamide or with ifosfamide/mesna and etoposide. However, both patients developed uncontrollable cerebrospinal fluid (CSF) dissemination of tumor and died within 6 months of diagnosis, despite intrathecal chemotherapy and irradiation for one and very high-dose intravenous methotrexate (33 g/m2) for the other. This rare tumor can respond to parenteral antisarcoma chemotherapy, but better strategies are needed to prevent CSF spread and ultimate demise. Early institution of intrathecal cytostatic agents may retard or prevent CSF dissemination and prolong survival.

Child, Preschool↗
PubMed1994

Prevention of radiation enteritis in children, using a pelvic mesh sling.

Between 1986 and 1991, the authors used polyglycolic acid mesh slings (placed at or above the sacral promontory) in eight children with pelvic malignancies to exclude all small bowel from the pelvis during pelvic radiation therapy. The only complications of this treatment were prolonged postoperative ileus (one patient) and temporary, partial small bowel obstruction (one patient). The average amount of radiation administered to the pelvis postoperatively was 5,349 +/- 556 cGy. In one of the eight patients, gastrointestinal symptoms (diarrhea for 24 hours) developed during radiation therapy. Early radiological evaluation confirmed that the small bowel was out of the pelvis in all five of the patients studied. Mesh disruption occurred between 2 and 5 months postoperatively (mean, 3.4 +/- 1.5 months) and was often identified symptomatically by the patient. Seven of the eight survived, with disease remission in six. Pelvic disease was absent at the time of death in the one patient who did not survive. Throughout the follow-up period (mean, 20 months) no survivor has had delayed symptoms of radiation enteritis. In children with pelvic malignancies in whom aggressive application of pelvic irradiation is required, the use of an absorbable pelvic mesh sling appears efficacious in preventing radiation-associated enteritis.

Child↗
PubMed1994

Polymorphism at codon 36 of the p53 gene.

A polymorphism at codon 36 in exon 4 of the p53 gene was identified by single strand conformation polymorphism (SSCP) analysis and direct sequencing of genomic DNA PCR products. The polymorphic allele, present in the heterozygous state in genomic DNAs of four of 100 individuals (4%), changes the codon 36 CCG to CCA, eliminates a FinI restriction site and creates a BccI site. Including this polymorphism there are four known polymorphisms in the p53 coding sequence.

Base Sequence↗