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S L Cohn

Publications and source records attributed to S L Cohn.

87 records · Page 5Linked to original sources
PubMed1987

Locked flexible intramedullary nails in treatment of unstable femoral fractures.

Twenty patients with unstable femoral fractures were treated with distally locked flexible intramedullary nails. We present our surgical technique and our results. The method has the following advantages: it prevents rotational malalignment and shortening, it is a closed procedure, no reaming is necessary, there is no increase in c-arm time, and there is minimal increase in operative time. Locked flexible intramedullary nails should be used in patients with unstable femoral fractures who have dense metaphyseal bone. Osteopoenia is a contraindication to this method as it increases the risk of nail penetration into the hip.

Adolescent↗
PubMed1987

N-myc amplification in an infant with stage IVS neuroblastoma.

N-myc amplification is most frequently found in neuroblastoma from patients with stage III and IV disease. Recently a significant association between genomic amplification and poor prognosis has been demonstrated. The primary tumors studied from patients with stage IVS disease have reportedly had a single copy of N-myc, and these patients are alive without progressive disease. We report a patient with stage IVS neuroblastoma with N-myc amplification who developed widespread metastasis within 6 months of diagnosis. The same correlation between oncogene copy number and progressive disease that has been seen in those patients with stage II, III, and IV disease was seen in this patient with stage IVS neuroblastoma.

Gene Amplification↗
PubMedDate not supplied

Detection of MYCN gene amplification in neuroblastoma by fluorescence in situ hybridization: a pediatric oncology group study.

To assess the utility of fluorescence in situ hybridization (FISH) for analysis of MYCN gene amplification in neuroblastoma, we compared this assay with Southern blot analysis using tumor specimens collected from 232 patients with presenting characteristics typical of this disease. The FISH technique identified MYCN amplification in 47 cases, compared with 39 by Southern blotting, thus increasing the total number of positive cases by 21%. The major cause of discordancy was a low fraction of tumor cells (< or =30% replacement) in clinical specimens, which prevented an accurate estimate of MYCN copy number by Southern blotting. With FISH, by contrast, it was possible to analyze multiple interphase nuclei of tumor cells, regardless of the proportion of normal peripheral blood, bone marrow, or stromal cells in clinical samples. Thus, FISH could be performed accurately with very small numbers of tumor cells from touch preparations of needle biopsies. Moreover, this procedure allowed us to discern the heterogeneous pattern of MYCN amplification that is characteristic of neuroblastoma. We conclude that FISH improves the detection of MYCN gene amplification in childhood neuroblastomas in a clinical setting, thus facilitating therapeutic decisions based on the presence or absence of this prognostically important biologic marker.

Blotting, Southern↗
PubMedDate not supplied

Clinical impact and prognostic value of metaiodobenzylguanidine imaging in children with metastatic neuroblastoma.

PURPOSE: The clinical value of metaiodobenzylguanidine (mIBG) scintigraphy in patients with disseminated neuroblastoma (NB) at the time of diagnosis and after induction chemotherapy was evaluated. PATIENTS AND METHODS: The medical records and imaging studies of 30 patients with stage 4 NB who underwent mIBG scintigraphy and 99mTc hydroxy methylene diphosphonate bone scintigraphy at the time of diagnosis were reviewed. Scores were calculated for the mIBG and bone scintigrams, and outcome according to the initial and follow-up imaging studies was determined. RESULTS: Discrepancies between bone scintigraphy and mIBG osteomedullary localization were seen in six patients. For the entire cohort, 2-year event-free survival did not significantly differ for the group of patients with initial mIBG or bone scintigraphy scores > or = 10 compared to those with scores < 10 (P = 0.23 and 0.61, respectively). However, for patients older than 1 year, a trend associating worse outcome with mIBG scores > or = 10 at diagnosis was seen (P = 0.08). A trend correlating abnormal mIBG scintigraphy after induction therapy and poor outcome was also observed (P = 0.09). Outcome did not correlate with the results of the bone scintigram studies performed after induction chemotherapy (P = 0.68). CONCLUSION: Because a discordance between mIBG and bone scintigraphy results were seen in a subset of stage 4 NB patients, both imaging studies should be performed at the time of diagnosis. mIBG imaging studies performed at the time of diagnosis and after induction chemotherapy may be of prognostic value, particularly in stage 4 patients older than 1 year.

3-Iodobenzylguanidine↗
PubMedDate not supplied

Natural history and biology of stage A neuroblastoma: a Pediatric Oncology Group Study.

PURPOSE: To prospectively analyze the outcome of patients with Stage A neuroblastoma (NB) treated with surgery alone, especially with regard to the prognostic significance of age, tumor site, MYCN copy number, tumor cell ploidy, and histology. PATIENTS AND METHODS: The clinical course of 329 patients with Stage A disease registered on the POG NB Biology Study #9047 between February, 1990 and October, 1997 were evaluated. Age, tumor site, MYCN copy number, tumor cell ploidy, and histology were analyzed for their impact on event-free survival (EFS) and survival (S). RESULTS: The 5-year estimated EFS and S rates for the 329 patients were 91% (+/-3%) and 96% (+/-2%), respectively. The EFS rate was similar for infants younger than 12 months and children age 12 months or older, but age older than 12 months was predictive of lower S rates (P = 0.044). Patients with adrenal, abdominal non-adrenal, thoracic, and cervical tumors had similar S rates. The majority of patients had tumors with favorable biologic features, and only 3% had MYCN amplification. For infants with diploid tumors, the EFS rate was 82% (+/-16%), but effective therapy yielded an S rate of 100%. Rate of S was 80% (+/-26%) and 64% (+/-27%) for patients with unfavorable tumor histology and MYCN-amplified tumors, respectively. CONCLUSION: The outcome for patients with Stage A NB treated with surgery alone is excellent. Although EFS and S rates were significantly worse for patients with MYCN-amplified tumors, a subset achieved long-term remission after surgery alone. For patients with Stage A and MYCN amplification, additional factors are needed to distinguish the patients who will achieve long-term remission with surgery alone from those who will develop recurrent disease.

Abdominal Neoplasms↗
PubMedDate not supplied

Evidence for molecular heterogeneity in human ganglioneuroblastoma.

Ganglioneuroblastomas are tumors of sympathetic cell origin that contain both primitive neuroblastomatous and mature ganglioneuromatous elements. It is thought that these tumors arise from a single cellular clone and that the morphologically distinct components of ganglioneuroblastomas represent cells in different stages of differentiation. Two pathologic variants of this tumor, composite and diffuse, have been described; metastasis is more commonly seen with composite ganglioneuroblastomas. We analyzed a composite ganglioneuroblastoma for N-myc copy number at initial resection and 2 years later after progressive disease. In the second sample the more differentiated portion of the tumor was analyzed separately from the neuroblastic foci for N-myc copy number and DNA ploidy. The DNA content and N-myc copy number differed in the two morphologically discrete areas of the tumor, suggesting that at least two clones were present. More composite ganglioneuroblastomas need to be examined to determine whether these tumors are largely composed of tumor cell populations with molecular heterogeneity.

Aneuploidy↗