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Biomedical subjects

J Michon

Publications and source records attributed to J Michon.

At least 19 recordsLinked to original sources
PubMed2007

hSNF5/INI1-deficient tumours and rhabdoid tumours are convergent but not fully overlapping entities.

Rhabdoid tumours (RTs) are rare but highly aggressive tumours of childhood. Their rarity and their miscellaneous locations make the diagnosis particularly challenging for pathologists. Central nervous system and peripheral RTs have been associated with biallelic inactivation of the hSNF5/INI1/SMARCB1 (hSNF5/INI1) tumour suppressor gene. Immunohistochemistry (IHC) with a monoclonal anti-hSNF5/INI1 antibody has recently been proposed as an efficient diagnostic tool for RTs. We have conducted a retrospective study of 55 tumours referred to our institution with a suspicion of RT. This analysis included pathological review, IHC with anti-hSNF5/INI1 antibody, and molecular investigation using quantitative DNA fluorescent analysis and sequencing of the nine exons of hSNF5/INI1. The molecular lesion could be detected in 37 of the 39 cases exhibiting negative staining for hSNF5/INI1. In the two discrepant cases, the lack of detection of genetic abnormality was probably owing to the presence of a high number of non-tumour cells in the samples. This indicates that hSNF5/INI1 IHC is very sensitive and highly specific for the detection of hSNF5/INI1 loss-of-function. Among the 38 cases with typical RT histological features, six failed to exhibit hSNF5/INI1 mutation and stained positive for hSNF5/INI1. This strongly supports the evidence of a second genetic locus, distinct from hSNF5/INI1, associated with RT. Conversely, seven tumours with histological features poorly compatible with RT stained negative for hSNF5/INI1; they nevertheless exhibited an age of onset and a clinical behaviour similar to RT. This suggests that hSNF5/INI1 inactivation is not strictly limited to typical RT but characterizes a wider family of hSNF5/INI1-deficient tumours. Consequently, we believe that anti-hSNF5/INI1 IHC should be performed widely, even when the pathological characteristics are not typical. The molecular investigation should be performed in infants when a rhabdoid predisposition syndrome is suspected.

Adult↗
PubMed2006

Incidence and prognostic value of tumour cells detected by RT-PCR in peripheral blood stem cell collections from patients with Ewing tumour.

To retrospectively evaluate the incidence of tumour cell contamination of peripheral blood stem cell (PBSC) collections and to correlate these data with the clinical outcome after high-dose chemotherapy (HDCT) with stem cell rescue in patients with a high-risk Ewing tumour. Peripheral blood stem cell collections obtained from 171 patients were analysed. Tumour contamination was assessed by reverse transcriptase-polymerase chain reaction (RT-PCR). The files of 88 patients who underwent HDCT followed by PBSC reinfusion were reviewed in detail, and their outcome compared to the PBSC RT-PCR results. Seven of 88 PBSC collections (8%) contained tumour cells as detected by RT-PCR. Peripheral blood stem cells were collected after a median of five cycles of chemotherapy. No clinical factor predictive of tumour cell contamination of PBSC harvest could be identified. Event-free survival (EFS) and overall survival (OS) of the whole study population were 45.3 % and 51.8 % at 3 years from the date of the graft, respectively. Forty-five patients relapsed with a median time of 15 months after graft, only four of whom had tumour cell contamination of the PBSC harvest. Tumour cell contamination of PBSC collection is rare and does not seem to be associated with a significantly poorer EFS or OS in this high-risk population.

Adolescent↗
PubMed2006

Final height and gonad function after total body irradiation during childhood.

Short stature and gonad failure can be a side effect of total body irradiation (TBI). The purpose of the study was to evaluate the factors influencing final height and gonad function after TBI. Fifty young adults given TBI during childhood were included. Twenty-seven had been treated with growth hormone (GH). Those given single 10 Grays (Gy) or fractionated 12 Gy TBI had similar characteristics, GH peaks, final heights and gonad function. After the end of GH treatment, 11/20 patients evaluated had GH peak >10 microg/l. Final height was <-2s.d. in 29 (58%). The height loss between TBI and final height (2.4+/-1.1 s.d.) was greater in those who were younger when irradiated (P<0.0001). When the GH-treated and -untreated patients were analyzed separately, this loss was correlated with the age at TBI at 4-8 years for the GH-treated and at 6-8 years for the untreated. Boys showed negative correlations between testicular volume and plasma follicle-stimulating hormone (FSH, P=0.0008) and between plasma FSH and inhibin B (P=0.005) concentrations. We concluded that the indications for GH treatment should be mainly based on the age at irradiation, taking into account the GH peak. The plasma FSH and inhibin B concentrations may predict sperm function.

Adolescent↗
PubMed2005

[Functional results of retinoblastoma treatment with local treatment used in isolation or associated with chemotherapy].

INTRODUCTION: Because of long-term complications of external beam radiation in retinoblastoma, a new therapeutic modality using chemotherapy and local treatments is used whenever possible. We conducted a retrospective study to evaluate visual results. PATIENTS AND METHOD: We studied visual acuity and ocular side effects in children presenting uni- or bilateral retinoblastoma in whom we were able to achieve conservative management without external beam treatment. The treatments that were used included chemotherapy, chemothermotherapy, diode laser, iodine 125 plaque brachytherapy, and cryotherapy. The initial characteristics (diameter, subretinal or vitreous seeding, and location) of each tumor, the treatments used, their results, and the visual function after age 4 years were recorded. RESULTS: We treated 429 children for retinoblastoma at the Curie Institute between October 1994 and December 2002. Two hundred twenty-seven eyes had conservative treatment without external beam. We were able to study the visual function in 102 eyes at a median age of 67 months. The median follow-up after the end of the treatment was 5 years. The mean visual acuity was 20/37 and 60% of the children had visual acuity of more than 20/40. Macular alteration was observed in 34 eyes. Statistical analysis showed that a larger tumor diameter of the retinal surface (p<0.0003) and location close to the macula (p<0.0001) were the most significant risk factors for vision loss. CONCLUSION: The visual results of the treatment of retinoblastoma by chemotherapy and local treatments is good when the tumors are not located close to the macula. Larger tumors also have a worse prognosis for vision.

Child, Preschool↗
PubMed2005

Cost effectiveness of day 5 G-CSF (Lenograstim) administration after PBSC transplantation: results of a SFGM-TC randomised trial.

This randomised trial was designed to compare two groups treated with different G-CSF administration schedules with a third group receiving no G-CSF, after autologous peripheral blood stem cell transplantation (APBSCT). Children and adults with haematological malignancies or solid tumours were randomly assigned to receive either 150 microg/m2/day of Lenograstim starting on day 1 (G1) or on day 5 (G5) post APBSCT, or no Lenograstim (G0). Randomisation was stratified according to the conditioning regimen (Busulfan vs TBI vs no Busulfan and no TBI) and the graft CD 34+ cell count. A total of 240 patients were randomised; 239 were evaluable. All three patient groups were comparable. Median duration of neutropenia was 9 days (4-40), and 10 days (5-15) in the G1 and G5 groups, respectively, significantly shorter than in the G0 group, 13 days (7-36) (P < 0.0001). No difference was observed in the duration of thrombocytopenia, transfusion support and extra-haematological complications. The duration of post transplant hospitalisation was significantly shorter in adults who received G-CSF. Clinical and cost arguments favour the initiation of G-CSF on day 5 in adults. The same policy could be applied in children given that clinical management is easier and costs are similar.

Adolescent↗
PubMed2004

[Neonatal localized neuroblastoma: 52 cases treated from 1990 to 1999].

UNLABELLED: Neuroblastoma is the most frequent tumor observed in the newborn. The aim of this study was to review clinical features, treatment and outcome of newborns diagnosed with a localized neuroblastoma. POPULATION AND METHODS: Data from 52 cases treated according to the NBL 90 and 94 protocols between 1990 and 1999 in 18 French centers of pediatric oncology were analyzed. RESULTS: The median age at diagnosis was 12 days (range 0-28) with antenatal detection in 14 patients (27%). Tumor location was abdominal in 40 patients (adrenal in 20 of the 40), thoracic in eight, pelvic in three, and cervical in one. N-myc amplification was observed in one out of 40 evaluable cases. The size of the primary tumor was less than 5 cm in 25 cases, between 5 and 10 cm in 25 and more than 10 cm in two. Dumbbell tumor was observed in seven, of whom five had neurological deficit. One child died from hemorrhage after fine needle biopsy during diagnostic procedure. Primary surgical resection was attempted in 37 infants, of whom two died of surgery related complications and three had nephrectomy. Tumor was deemed as unresectable in 14 patients, and primary chemotherapy was given followed by surgical excision in 12. One of them died a few days after the beginning of chemotherapy. As a whole, continuous complete remission was achieved in 48 children, four of them after relapse. Overall survival was 92% with a median follow-up of 46 months (0-113 months). CONCLUSION: The excellent prognosis of localized NB in neonates needs very restrictive surgical indications, with well-established anatomic and imaging criteria. Indeed, chemotherapy based on weight and managed by expert teams should allow to perform surgical excision in safer conditions for unresectable tumors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[Prognosis of neuroblastoma in childhood. Methods of assessment and clinical use].

Neuroblastoma and its benign counterpart, ganglioneuroma, are pediatric neuroblastic tumors arising in the sympathetic nervous system from neural-crest cells. Neuroblastoma, the most common extra-cranial solid tumour during childhood, is unique for its broad spectrum of clinical virulence from spontaneous remission to rapid and fatal progression despite intensive multimodality therapy. To a large extent, outcome could be predicted by the stage of disease and the age at diagnosis. However, a number of molecular events in neuroblastoma tumors, accounting for the variability of outcome and response to therapy, have been identified over the past decades. Among these, MYCN amplification is the most relevant prognostic factor and was the first genetic marker, in paediatric oncology, to be included in clinical strategies as a guide for therapeutic decision. This has allowed the most suitable intensity of therapy to be delivered according to a risk-stratified strategy, from observation to megadose chemotherapy with stem cell transplantation. Recent advances in understanding the biology and genetics of neuroblastoma will ultimately allow to select poor-risk patients for appropriate future biologically based therapies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2004

[4S neuroblastoma with bilateral adrenal tumors].

UNLABELLED: 4S neuroblastoma with bilateral adrenal involvement is defined by small primitive tumors (stage 1 or 2) with disseminated disease restricted to the liver, skin, and/or bone marrow. Children are less than one year old. These tumors are rare and of multicentric origin. PATIENTS AND METHODS: Our multicentric study analyzed four children less than four months old at diagnosis. RESULTS: All had a favourable histology, with normal MYC-N copy number, and one case had a diploid tumor. The four patients had first supportive care at the beginning, but three cases received chemotherapy because of progressive disease, with liver radiotherapy in two cases because of massive hepatomegaly; three cases had surgery (unilateral adrenal resection in two cases and bilateral in one case) and one had only a biopsy. Surgery was the only treatment in one case. One patient relapsed 17 months after initial treatment and was treated with intensive chemotherapy and stem cell rescue. The outcome is favorable for the four patients, without evidence of recurrent disease. CONCLUSION: Children with 4S neuroblastoma with bilateral adrenal tumors have a good prognosis. Treatment should be the less aggressive as possible. The group with favorable prognostic parameters should have supportive care if spontaneous regression occurs. But we have to treat with chemotherapy neonates with massive hepatomegaly and children with one or more unfavorable prognostic factors (unfavorable histology, high MYC-N copy number).

Adrenal Gland Neoplasms↗
PubMed2004

Ex vivo expansion of megakaryocyte precursor cells in autologous stem cell transplantation for relapsed malignant lymphoma.

To evaluate the impact of ex vivo expanded megakaryocyte (MK) progenitors on high-dose chemotherapy-induced thrombocytopenia, we conducted a phase II study in 10 patients with relapsed lymphoma. Two fractions of peripheral blood progenitor cells (PBPC) were cryopreserved, one with enough cells for at least 2 x 10(6) CD34+ cells/kg and a second obtained after CD34+ selection. Ten days before autologous stem cell transplantation, the CD34+ fraction was cultured with MGDF+SCF for 10 days. After BEAM (BCNU, cyclophosphamide, cytarabine, and melphalan) chemotherapy, patients were reinfused with standard PBPC and ex vivo expanded cells. No toxicity was observed after reinfusion. The mean fold expansion was 9.27 for nucleated cells, 2 for CD34+ cells, 676 for CD41+ cells, and 627 for CD61+ cells. The median date of platelet transfusion independence was day 8 (range: 7-12). All patients received at least one platelet transfusion. In conclusion, ex vivo expansion of MK progenitors was feasible and safe, but this procedure did not prevent BEAM-induced thrombocytopenia. Future studies will determine if expansion of higher numbers of CD34+ cells towards the MK-differentiation pathway will translate into a functional effect in terms of shortening of BEAM-induced thrombocytopenia.

Antigens, CD34↗
PubMed2003

Localised and unresectable neuroblastoma in infants: excellent outcome with low-dose primary chemotherapy.

The purpose of this study was to evaluate the efficacy of low-dose chemotherapy in infants with localised and unresectable neuroblastoma (NB). All consecutive infants with localised NB and no N-myc amplification were eligible in the SFOP-NBL 94 study. Primary tumour was deemed as unresectable according to imaging data showing any risk of immediate resection. Diagnostic procedures and staging were conducted according to INSS recommendations. For children, provided that they had no threatening symptom (i.e. vital risk or dumb-bell NB with neurologic deficit), chemotherapy consisted in low-dose cyclophosphamide (5 mg(-1)kg day(-1) x 5 days) and vincristine (0.05 mg kg(-1) at day 1)-CV and repeated one to three times every 2 weeks until surgical excision can be safely performed. No postoperative treatment was given. Between January 1995 and December 1999, 134 consecutive infants with localised NB were registered in the study, of whom 39 had an unresectable NB without N-myc amplification. Among them 28 had no threatening symptom and received CV according to the protocol. Objective response was observed in 14 (50%) and the other 14 were given second-line chemotherapy because of no response. Surgery was attempted in 38 patients including 14 after CV alone, leading to complete resection in 23. Relapses occurred in four patients all local. Survival and event-free survival were 100 and 90+/-5% with a median follow-up of 55 months (range 33-93). In conclusion primary low-dose chemotherapy without anthracyclines is efficient in about half of the infants presenting with an unresectable NB and no N-myc amplification, allowing excellent survival rates without jeopardising their long-term outcome even for nonresponding patients who received standard regimen.

Antineoplastic Agents↗
PubMed2003

Treatment of stage 4s neuroblastoma--report of 10 years' experience of the French Society of Paediatric Oncology (SFOP).

Stage 4s neuroblastoma (NB) is usually associated with a favourable outcome, despite a large tumour burden, as spontaneous regression frequently occurs. However, in some infants rapid disease progression can be observed with severe functional impairment. Thus, for all patients the potential risks of cytotoxic therapy must be weighed against the benefits of early medical intervention. We have retrospectively reviewed the charts of 94 infants treated for stage 4s NB in centres of the French Society of Paediatric Oncology between 1990 and 2000, and describe the different first-line treatment approaches that were, successively, liver irradiation, chemotherapy using a cyclophosphamide-vincristine regimen, and chemotherapy using a carboplatin-etoposide regimen. The overall survival was 88% (+/-7.6%), with a mean follow-up of 64 months. Elevated serum neuron-specific enolase (>100 nmol ml(-1)), ferritin (>280 ng ml(-1)) and urinary dopamine levels (>2500 nmol mmol(-1) creatinine) were associated with a poor outcome, as were the genetic markers N-myc amplification and chromosome 1p deletion (P<0.0005 and P=0.0016, respectively). Patients who required medical intervention at diagnosis fared worse than those who received supportive treatment only (P<0.005). The clinical evolution observed with the different successive treatment approaches suggests that if infants do require therapy, the prompt initiation of a more intensive regimen such as carboplatin-etoposide may be more beneficial.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

Quality assessment of genetic markers used for therapy stratification.

PURPOSE: Therapy stratification based on genetic markers is becoming increasingly important, which makes commitment to the highest possible reliability of the involved markers mandatory. In neuroblastic tumors, amplification of the MYCN gene is an unequivocal marker that indicates aggressive tumor behavior and is consequently used for therapy stratification. To guarantee reliable and standardized quality of genetic features, a quality-assessment study was initiated by the European Neuroblastoma Quality Assessment (ENQUA; connected to International Society of Pediatric Oncology) Group. MATERIALS AND METHODS: One hundred thirty-seven coded specimens from 17 tumors were analyzed in 11 European national/regional reference laboratories using molecular techniques, in situ hybridization, and flow and image cytometry. Tumor samples with divergent results were re-evaluated. RESULTS: Three hundred fifty-two investigations were performed, which resulted in 23 divergent findings, 17 of which were judged as errors after re-evaluation. MYCN analyses determined by Southern blot and in situ hybridization led to 3.7% and 4% of errors, respectively. Tumor cell content was not indicated in 32% of the samples, and 11% of seemingly correct MYCN results were based on the investigation of normal cells (eg, Schwann cells). Thirty-eight investigations were considered nonassessable. CONCLUSION: This study demonstrated the importance of revealing the difficulties and limitations for each technique and problems in interpreting results, which are crucial for therapeutic decisions. Moreover, it led to the formulation of guidelines that are applicable to all kinds of tumors and that contain the standardization of techniques, including the exact determination of the tumor cell content. Finally, the group has developed a common terminology for molecular-genetic results.

Biomarkers, Tumor↗
PubMed2003

Peripheral blood stem cell collection in 24 low-weight infants: experience of a single centre.

Peripheral blood stem cells (PBSC) harvest may be difficult in young children. Extracorporeal separator line priming by red blood cells is usually required to improve haemodynamic tolerance and efficacy of collection. We present our experience with 24 children weighing less than 15 kg treated between January 1997 and September 1999, in whom we tried to avoid systematic blood priming. The median age and weight at the time of apheresis were 2.4 years and 12 kg, respectively. A total of 48 PBSC were performed. When haemoglobin was less than 12 g/dl, packed red cells were transfused before collection (40% of aphereses). The median cell yield per apheresis was 7.1 (2.2-30.6)x10(6)/kg CD34(+) cells and 16.0 (3.3-44.3)x10(5) CFU-GM/kg. Initial collection failed in three cases. Four children required an additional haematopoietic progenitor mobilization. This procedure allowed PBSC collection without transfusion in 37.5% of children, and was safe (two serious and five mild transient side effects) and effective (median CD34(+) cells collected per child: 7.1 x 10(6)/kg (4.6-30.6) and CFU-GM: 15.1 x 10(5)/kg (4.7-44.3)). Despite their low weight, insertion of a femoral catheter was avoided in 43% of children.

Blood Component Removal↗
PubMed2003

Laparoscopic adrenal surgery for neuroblastomas in children.

PURPOSE: The role of laparoscopy in children with neuroblastomas has not been fully defined. The laparoscopic approach to the adrenal gland is already largely used in adults and a few cases have been reported in children. We report the experience of a single surgical team center with laparoscopic adrenal surgery for neuroblastomas in children. MATERIALS AND METHODS: Between September 2000 and October 2002 laparoscopic adrenalectomy for neuroblastoma was performed in 9 patients (6 girls and 3 boys) with a mean age of 38 months (range 2 months to 9 years). Two tumors were detected prenatally and 7 postnatally. Preoperative diagnosis was neuroblastoma stage I in 4 cases and stage IV in 3 cases, and nondetermined suprarenal calcified masses in 2 cases. A 4 or 5-trocar transperitoneal approach was used in all cases. The adrenal tumors were completely excised, placed into a plastic bag and removed through the umbilical trocar site. RESULTS: All of the adrenal tumors were well encapsulated and completely excised. One of the 9 procedures was converted to open surgery because of adhesions to renal vessels. In 1 case a second hepatic localization was removed simultaneously, and in 3 cases 1 or more lymph nodes were resected. Average operative time was 85 minutes (range 45 to 170). There were no deaths. There were no postoperative complications, except 1 port site infection that was treated locally. Blood transfusion was not required. Average hospital stay was 4.5 days (range 2 to 10). Histological analysis of the 9 specimens (maximum length 6 cm) confirmed the diagnosis of neuroblastoma. N-myc status was studied in 8 of the 9 resected neuroblastomas and was amplified in 2 cases (both stage IV with preoperative biopsy). Average postoperative followup was 15 months (range 1 to 25). There was no local recurrence or metastasis, except in the case that required conversion to open surgery (local recurrence 7 months later). CONCLUSIONS: Laparoscopic adrenalectomy for neuroblastoma is safe and feasible in children, with good results. Experience with advanced laparoscopic surgery is required to achieve this result in optimal oncological conditions. Our short-term results must be reevaluated at long term, and further studies are needed to compare laparoscopy to open surgical techniques.

Adrenal Gland Neoplasms↗
PubMed2002

The LMCE5 unselected cohort of 25 children consecutively diagnosed with untreated stage 4 neuroblastoma over 1 year at diagnosis.

The Lyon-Marseille-Curie-Est (LMCE) of France cooperative group has previously reported successive series of unselected stage four children older than 1 year at diagnosis with metastatic neuroblastoma (LMCE 1 and 3). The goal of LMCE 5 study was to increase progression free survival rate as compared to LMCE 1 and 3. Based on improvements reported with post induction chemotherapy, the LMCE 5 used post induction for all children, but omitted total body irradiation and immunomagnetic purging in megatherapy regimen for all children. Twenty-five sequentially diagnosed children received an induction regimen which compared with previous induction included an increased dose of etoposide and cyclophosphamide, delivered similar dose of cisplatinum, and deleted doxorubicin and vincristin. After surgery treatment was stratified based on response and eligible children received etoposide carboplatin (LMCE 5A : n=10)+/-doxorubicin (LMCE 5B-C n=13) followed by megatherapy (melphalan without total body irradiation and unpurged peripheral blood stem cell rescue). The increase in drug doses during induction did not improve remission rate. The progression free survival at 6 years is 8%. It is significantly worse than LMCE 3, and equivalent to LMCE 1 study though toxic death rate has decreased with increasing experience. Failure to improve the response rate during induction and reducing the megatherapy regimen may be the main factors in this disappointing result. Modified strategies for induction, non toxic alternative to total body irradiation, and post megatherapy regimen should be developed.

Adolescent↗
PubMed2002

Granulocyte colony-stimulating factor in induction treatment of children with non-Hodgkin's lymphoma: a randomized study of the French Society of Pediatric Oncology.

PURPOSE: To determine whether granulocyte colony-stimulating factor (G-CSF; lenograstim) decreases the incidence of febrile neutropenia after induction courses in treatment of childhood non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: Patients were randomized to receive (G-CSF+) or not receive (G-CSF-) prophylactic G-CSF, 5 microg/kg/d, from day 7 until an absolute neutrophil count > or = 500/microL was sustained over 48 hours, after two consecutive induction courses of cyclophosphamide 1.5 or 3 g/m(2), vincristine 2 mg/m(2), prednisone 60 mg/m(2)/d x 5, doxorubicin 60 mg/m(2), high-dose methotrexate 3 or 8 g/m(2), and intrathecal injections (COPAD[M]) on protocols LMB89, LMT89, and HM91 of the French Society of Pediatric Oncology. RESULTS: One hundred forty-eight patients were assessable, 75 G-CSF+ and 73 G-CSF-. Although duration of neutropenia less than 500/microL was 3 days shorter in G-CSF+ patients (P = 10(-4)), incidence of febrile neutropenia (89% v. 93% in the first course, 88% v. 88% in the second course), durations of hospitalization and antimicrobial therapy, percentages of infections, mucositis, and transfusions were not significantly different. Although the percentage of G-CSF+ patients commencing the following course on day 21 was significantly higher (84% v 68% after the first and 57% v. 38% after the second course; P <.05), the median delay between the two courses was only 1 day less in G-CSF+ patients (median delay after first COPAD(M), 19 v. 20 days, P =.01; after second, 21 v. 22 days, P = not significant). Remission and survival rates were similar in both arms. CONCLUSION: This study demonstrates that G-CSF did not decrease treatment-related morbidity, nor increase the dose-intensity in children undergoing COPAD(M) induction chemotherapy for NHL.

Antineoplastic Combined Chemotherapy Protocols↗