Deep sedation in pediatric imaging: efficacy and safety of intravenous chlorpromazine.

BACKGROUND: The quality of MRI and CT depends largely on immobility of the patient during the procedure, which is often difficult to achieve without sedation in children below the age of 6 years. OBJECTIVE: To assess the efficacy and safety of intravenous chlorpromazine sedation for repeated imaging in young children treated for cancer. MATERIALS AND METHODS: From July 2003 to January 2007, information on children younger than 6 years of age having MRI or CT was prospectively collected. Forty-five minutes before the scan, a 10-min infusion of chlorpromazine 0.5 mg/kg was administered and managed by non-anesthetic staff. Patient monitoring included continuous measurement of pulse, respiration, oxygen saturation and arterial blood pressure. Procedure-related parameters and adverse events were documented. Sedation was considered successful when the procedure was completed and at least 95% of images were usable. RESULTS: One-hundred-one procedures (82 MRI, 19 CT) were evaluated in 62 children, 3-74 months old. Adequate sedation was achieved in 96% of cases, with mean induction time, 22 min; mean duration of sleep, 72 min, and mean duration of procedure, 33 min. Mean time spent in the radiology unit was 104 min. Ninety-six percent of imaging procedures were successfully completed. No cardiac, respiratory, neurological or allergic complication occurred. CONCLUSION: Intravenous chlorpromazine is safe and effective for procedural sedation in young children with cancer undergoing MRI and CT.

[Disseminated actinomycosis treated with clindamycin]. / Actinomycose disséminée traitée par clindamycine.

Actinomycosis is a rare bacterial disease caused by Actinomyces spp., an anaerobic bacteria from the oropharynx, digestive, and female genital tracts. Initial clinical presentation often mimics malignancy, which can lead to a delay in diagnosis. Cervico-facial, genitourinary, digestive, and respiratory features are the most frequent. Few cases are reported in children and risk factors are not well known in this population. We report on the case of an 8-year-old boy with disseminated actinomycosis with cervico-facial, pulmonary, and bone involvement caused by Actinomyces israelii. The infiltrative appearance initially suggested malignancy and the patient was started on chemotherapy for presumed histiocytosis. Evaluation of subsequent tissue samples demonstrated the presence of filamentous structures consistent with fungal or filamentous bacterial infection. Prolonged culture yielded the correct diagnosis. The patient had a severe allergic reaction to piperacillin/tazobactam and was therefore transitioned to clindamycin to complete a 9-month course. This treatment, which has not been reported in children, led to a favorable clinical, biological, and radiological response, with a good clinical tolerance.

Sarcomas and malignant phyllodes tumours of the breast--a retrospective study.

BACKGROUND: Although most breast cancers are adenocarcinomas of the mammary gland, primary breast sarcomas may also arise from mammary gland mesenchymal tissue. The annual incidence of primary breast sarcoma is low and has been estimated at 45 new cases per 10 million women. These tumours are at high risk of recurrence and are known to have poor prognosis. Phyllodes tumours represent a specific subset of these breast soft tissue tumours. They are composed of a connective tissue stroma and epithelial elements. Pathological presentation ranges from grade I to malignant phyllodes tumours (grade III) where the stromal component clearly exhibits a sarcoma pattern. MATERIALS AND METHODS: SAPHYR (SArcoma and PHYllode Retrospective) is a retrospective study of the experience of Leon Bérard Cancer Centre (Lyon, France) from 1966 to August 2004. SAPHYR aims to describe the characteristics of primary breast sarcomas and to define potential survival factors to be evaluated in future prospective studies. RESULTS: We included 70 patients. Half of them presented at least one recurrence (35/70). Median disease-free-survival (DFS) was 1.15 years. At 3 years, median overall survival had not been reached and more than 61% of the patients were alive. Quality of surgical resection was significantly (p=0.036) different whether patients were in the R0 group (72%) or not (38%). No survival difference was found between malignant phyllodes (grade III) and other primary breast sarcomas (angiosarcomas excluded). Histology revealed three significantly (p=0.0003) different prognostic groups: phyllodes grade I and II (DFS=57%), angiosarcomas (DFS=7%) and phyllodes grade III and other primary breast sarcomas (DFS=45%). DISCUSSION: Phyllodes tumours and primary breast sarcomas are totally different from epithelial breast cancers and should be considered as a distinct group of rare tumours. The first goal of treatment is to achieve negative margins (R0). We propose to treat the patients according to the clinical practice guidelines in use for soft tissue sarcomas and address them to a reference centre for sarcoma. Treating rare tumours in the same place should permit us to standardise pathological data and to include patients into multicentric radiotherapy or chemotherapy protocols to improve overall survival. As further prospective studies are needed, European oncology groups must join their forces to create a prospective Rare Cancer Network.

Accuracy of core needle biopsy for the diagnosis of osteosarcoma: A retrospective analysis of 73 patients.

PURPOSE: The goals of this retrospective study were to evaluate the accuracy of core needle biopsy (CNB) for the diagnosis of osteosarcoma and to identify criteria that may predict failed CNB. MATERIALS AND METHODS: From 2002 to 2012, 73patients with a total of 73osteosarcomas underwent CNB. Patients demographics and procedure details were recorded, including tumor size, tumor characteristics (hemorrhagic or not, lytic, sclerotic [>50% bone condensation], or mixed), the type of anesthesia, the number of tissue samples, the size of the biopsy needle and pathology report. Procedures were analyzed in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: A diagnosis was not made in 5/73patients (6.8%) with an overall sensitivity of 93.1%, a specificity of 100%, a PPV of 100% and a NPV of 99.9%. No complications due to CNB were observed. No criteria were identified as predictors of CNB failure. CONCLUSION: Even in the presence of sclerotic tumors, CNB should be the first line diagnostic test for suspected osteosarcomas, pending performance by a well-trained radiologist and reading by a specialized pathologist. LEVEL OF EVIDENCE: IV.

Response rate accuracy in oncology trials: reasons for interobserver variability. Groupe Français d'Immunothérapie of the Fédération Nationale des Centres de Lutte Contre le Cancer.

PURPOSE: We evaluated the impact of an evaluation committee (EC) on patients' overall response status in a large multicenter trial in oncology. We identified reasons for disagreements between investigators and the EC. MATERIALS AND METHODS: The Cancer Renal Cytokine (CRECY) study was a French multicenter trial that tested cytokine therapy in 489 patients with metastatic renal cell carcinoma. Objective response (OR) evaluation included medical imaging and was studied according to international guidelines. A blinded peer review of all responders and litigious cases was performed by an EC. RESULTS: Major disagreements occurred in 40% and minor disagreements in 10.5% of the reviewed files. The number of significant tumor responses was reduced by 23.2% after review by the EC. Reasons for disagreements included errors in tumor measurements, errors in selection of measurable targets, intercurrent diseases, and radiologic technical problems. These reasons for disagreements are analyzed and discussed. CONCLUSION: We conclude that all therapeutic trial results should be reviewed by peer analysis of all presumed responders by an EC. International guidelines for response evaluation should be updated by including more reliable methods of measurements and definition of minimal imaging procedures.

Temozolomide in malignant gliomas of childhood: a United Kingdom Children's Cancer Study Group and French Society for Pediatric Oncology Intergroup Study.

PURPOSE: To determine the response rate of the malignant gliomas of childhood to an oral, daily schedule of temozolomide. PATIENTS AND METHODS: A multicenter, phase II evaluation of an oral, daily schedule of temozolomide (200 mg/m(2) on 5 consecutive days) was undertaken in children with relapsed or progressive, biopsy-proven, high-grade glioma (arm A) and progressive, diffuse, intrinsic brainstem glioma (arm B). Evidence of activity was defined by radiologic evidence of a sustained reduction in tumor size on serial magnetic resonance imaging scans. RESULTS: Fifty-five patients were recruited (34 to arm A and 21 to arm B) and received 215 cycles of chemotherapy. Grade 3/4 thrombocytopenia was the most frequent toxic event (7% of cycles). Prolonged myelosuppression resulted in significant treatment delays and dose reductions (17% and 22% of cycles, respectively). Two toxic deaths were documented and were related to myelosuppression and sepsis in one patient and pneumonia in a second. The overall (best) response rate was 12% for arm A (95% confidence interval [CI], 3 to 28 in the study cohort, and 2 to 31 for eligible patients) and 5% and 6%, respectively, for arm B (95% CI, 0 to 26 in the study cohort, and 0 to 27 for eligible patients). Stabilization of disease was also documented and was most noteworthy for brainstem gliomas, where two patients achieved both radiologic static disease and discontinued steroid medication. CONCLUSION: Despite moderate toxicity, objective response rates to temozolomide have been low, indicating that temozolomide has minimal activity in the high-grade gliomas of childhood.

Thrombocytopenia due to hypersplenism in oncological disease: partial splenic embolization during palliative treatment.

Hypersplenism is excess activity of the spleen, resulting in peripheral pancytopenia that predominates in platelet cell lines. Pancytopenia can be limited by reducing the volume of the functional spleen. However, in patients in very poor general condition, a splenectomy may not be possible, due to the risks of surgery and postoperative infection. Another therapeutic alternative in these patients is to reduce the volume of the spleen by super selective percutaneous splenic embolization. We report three cases of peripheral thrombocytopenia due to hypersplenism with a platelet count between 60,000 and 80,000/mm(3), which made it impossible to continue or start a chemotherapy protocol in these patients. For these patients, super selective partial embolization of the splenic parenchyma, with uncharged microspheres (250 microns) quickly resulted in a platelet count above 150,000/mm(3) so that chemotherapy could be continued or initiated.

Management of pediatric non-Hodgkin's lymphoma.

Over the past 15 years, significant progress has been made in the understanding of the molecular mechanism involved in malignant transformation of lymphocytes as well as in the management and treatment of non-Hodgkin's lymphoma (NHL) in childhood. Cyto-histological classifications and immunophenotyping of different types of NHL have contributed to the characterisation of three major subtypes of NHL in children i.e. Burkitt's lymphoma (BL), lymphoblastic lymphoma (LL) and large cell lymphoma (LCL). Precise staging of the disease at diagnosis is necessary before the onset of the treatment and should be performed as quickly as possible. Presence of bone marrow and central nervous system (CNS) involvement are major prognosis criteria. In most cases, surgery has no therapeutic role and is required only for diagnostic procedures. Similarly, several studies have demonstrated that irradiation of various sites including the CNS does not improve survival. Thus, NHL patients are usually treated with chemotherapy alone. BL and LL have distinct clinical presentations and require completely different chemotherapy protocols. After comparable induction phases with intensive chemotherapy regimens, the former is usually treated with a short consolidation phase while the latter receives a long lasting consolidation consisting of intermittent chemotherapy for at least one year. The prognosis of stage I-II, and III-IV bone marrow negative NHL of children is excellent with respectively 95% and 75% long term survival. However, patients with concomittent CNS and bone marrow involvement in both histological subtypes have a considerably worse prognosis with only 30% long term survival.(ABSTRACT TRUNCATED AT 250 WORDS)

A phase-II study of adoptive immunotherapy with continuous infusion of interleukin-2 in children with advanced neuroblastoma. A report on 11 cases.

Nine children with poor prognosis neuroblastoma have been treated by continuous infusion of IL-2 and autologous LAK cells, as described previously by West et al. in adult patients. Six patients were in relapse after high-dose chemotherapy and autologous BMT and three presented with primary refractory disease after conventional therapy. Although patients were very young (median age 6 years; average weight 17 kg), infusion of IL-2, cytapheresis and reinjection of LAK cells appeared feasible with the usual and transient complications observed with IL-2. Haematological toxicity, although reversible, was more important than usually described and due to the presence of bone-marrow metastases in 8 of the 9 patients. Life-threatening toxicity was observed in only one of the admission centres and was probably due to the rapid reinjection of a very large number of activated cells. Two patients presenting with very active disease after high-dose chemotherapy and autologous or allogeneic BMT received IL-2 alone, at 120 days and at 90 days after the graft. The reactivation of grade-II GVHD was the major complication in the patient treated after an allograft, whereas no BMT-related toxicity was observed in the patient treated after the autologous BMT. Immunological modifications induced by IL-2 were very different between these patients. As expected, a preferential outgrowth of NK cells with both NK and LAK activity was observed in the patient treated just after the autograft. In contrast, in the patient treated after an allograft and in the 9 patients in relapse, T lymphocytes remained the major mononuclear cell population with a very large excess of CD8+ T cells. All patients progressed after the first induction cycle with the exception of the only patient treated after autologous BMT who reached a very good partial remission with disappearance of the local tumor and bone metastases. Although very preliminary, these data clearly show that the efficacy of IL-2 largely depends on the patient's immunological status with the optimal effect being observed when IL-2 is given in the first few months following an autograft.

Assessment of percutaneous fine needle aspiration cytology as a technique to provide diagnostic and prognostic information in neuroblastoma.

The International Neuroblastoma Staging System (INSS) criteria for diagnosis requires an unequivocal pathological diagnosis and favours the identification of prognostic markers in the samples. Surgical biopsies of the primary tumour and bone marrow (BM) sampling in metastatic disease constitute the major sources of tumour material for the laboratory. We analysed the possibility of percutaneous fine needle aspiration cytology (FNAC) constituting an alternative procedure to the conventional technique of sampling of the primary tumour in children with advanced neuroblastoma. From July 1987 through July 1998, 64 consecutive children suspected of having advanced neuroblastoma and referred to our institution underwent percutaneous FNAC of deeply located tumours. FNAC was performed using 22-gauge needles under ultrasound guidance, before any chemotherapy and within the first days following admission. No complication occurred after FNAC. The median number of the extracted tumour cells was 2.3x10(6) (range: 0-40.6x10(6)). Cytology analysis was possible in 59/64 cases (92%) and immunocytochemistry in 56/64 (88%) allowing confirmation of the diagnosis. N-Myc analysis was available in 46/64 (72%). In addition, the presence of a partial deletion of chromosome 1p (del 1p) was assessed, since 1992, in 24/47 cases (51%), where enough cells were available. FNAC of deeply located advanced neuroblastoma is safe and information is available in a few hours after admission. The provided material is reliable for confirmation of diagnosis and analysis of biological prognostic markers in the majority of cases. More invasive tumour sampling procedures are required only in selected cases.

Evaluation of CD44 prognostic value in neuroblastoma: comparison with the other prognostic factors.

CD44 gene products are potential markers of aggressiveness in different tumour models, a result which prompted us to study clinical neuroblastoma (NB) specimens. CD44 expression was determined by immunostaining of 52 tumour samples from newly diagnosed NB with a monoclonal antibody (J173) directed against an epitope common to all CD44 isoforms. CD44 immunoreactivity was detected in 37 of the tumours (71%). CD44 was expressed in all 22 NBs with favourable prognoses (stages 1, 2 or 4S), but only 50% (15/30) of advanced NB (stages 3 and 4) (P < 10(-4)), suggesting that the absence, rather than the overexpression, of CD44 is a signal of tumour aggressiveness. The cumulative progression-free survival was significantly longer in patients with CD44 positive tumours compared with patients with CD44 negative tumours (P < 10(-5)). More importantly, progression-free survival was also significantly higher in CD44 positive patients within the high-risk group (P < 0.01). In univariate analysis, we tested the prognostic value of tumour expression of CD44 in comparison with tumour stage, age, tumour histology, and presence or absence of amplification of the MYCN protooncogene. All five measures had significant prognostic value. The expression of CD44 and the absence of MYCN amplification were the most powerful predictors of a favourable outcome. In a multivariate analysis of these measures, CD44 expression and tumour stage were the only independent prognostic factors for the prediction of patient survival. NB is the first clinical model described in which tumour aggressiveness correlates with repression rather than stimulation of CD44 expression. We recommend the use of CD44 as an additional biological marker in the initial staging of NB.

Does nephroblastomatosis influence the natural history and relapse rate in Wilms' tumour? A single centre experience over 11 years.

The presence of multifocal or diffuse nephrogenic rests (NRs) in one or both kidneys is termed nephroblastomatosis (Nbm). Nbm may be a predisposing factor for Wilms' tumour (WT). The aim of this retrospective study was to evaluate the impact of Nbm on the outcome of WT in children. We assessed the outcome of 81 children with Wilms tumours and practical implications of Nbm in the treatment and follow-up. All the pathology slides have been reviewed in 1997. 63 had WT without Nbm (group A) and 18 had WT associated with Nbm (group B). There was no statistical difference between the two groups according to the age at diagnosis and histology. Clinical abnormalities were more frequent in group B (33 versus 8%). There was no statistical difference between the percentage of stage IV in both groups, but bilaterality (stage V) was present only in the group B. Relapse was observed in 20/81 patients (25%): 11 (17%) in group A and 9 (50%) in group B. Mean delay of relapse was longer (25 months) in group B than in group A (10 months). For the whole population, with a median follow-up of 9 years, the event-free survival (EFS) and the overall survival (OS) probabilities were respectively 74%+/-10 and 83%+/-9 at 120 months. The difference in EFS between groups A (82+/-9%) and B (38%+/-29) was significant (P=0.004). The discovery of Nbm in the non-tumoral part of the kidney with WT can be an adverse factor and in particular favours the subsequent development of a new Wilms tumour. It justifies separate follow-up guidelines.

Evaluation of core needle biopsy as a substitute to open biopsy in the diagnosis of soft-tissue masses.

Open biopsy is recommended for a soft-tissue sarcoma (s-t-S) diagnosis. Core needle biopsy (CNB) was recently associated with minimal morbidity, cost and time-consumption, but also potential inaccuracy. Its diagnostic utility was investigated retrospectively in 110 patients with soft-tissue masses (s-t-M) undergoing CNB between September 1994 and September 2000. Sensitivity (Se), specificity (Sp), positive (PPV) and negative (NPV) predictive values were determined for malignancy (benign/malign), soft-tissue tumour (yes/no), and sarcoma diagnosis (yes/no), comparing CNB and the best standard test available; concordance was evaluated. 103/110 CNB were suitable for analysis. Final diagnosis was 23 benign tumours (19%), 65 s-t-S (59%), 9 lymphomas (8%), 6 fibromatoses (desmoid) (5%) and 7 carcinomas (6%). CNB Sp and PPV were 100%, Se was 95, 99 and 92%, and NPV 85, 95 and 88% for diagnosing malignancy, soft-tissue tumour and sarcoma. CNB Se and NPV were 100% for malignancy, connective tumour and sarcoma in lymphomas, high-grade sarcomas and desmoid tumours. In low grade sarcomas, Se was 94 and 85%, and NPV 84 and 77% for malignancy and sarcoma. Histological grade on CNB seems uneasy, except for grade-III tumours. CNB is accurate, not misleading for s-t-M diagnosis, avoids open biopsy complications, and allows one-surgery or neo-adjuvant chemotherapy planning when combined with appropriate imaging.

Choroid plexus carcinomas in childhood: clinical features and prognostic factors.

OBJECTIVE: Choroid plexus carcinomas are rare tumors with dismal prognosis. The role of surgery has been well established, but the benefit of either chemotherapy or radiotherapy remains controversial. To determine prognostic factors and effects of different therapeutic modalities on the outcome, we have reviewed the French experience of choroid plexus carcinoma. METHODS: Twenty-two children were registered in the Société Française d'Oncologie Pédiatrique between 1984 and 1995. All these children underwent surgical resection of the primary tumor. The intent of postoperative treatment was to delay or to avoid radiation therapy. Nineteen children received postoperative treatment, with chemotherapy in 17 and radiation therapy in 2. Two responding patients underwent high-dose chemotherapy with stem cell rescue. RESULTS: The 5-year survival rate was 26%. The sole relevant prognostic factor was the extent of surgery. Patients with total or gross total resection had a 86% survival rate. Survival did not correlate with age, sex, delay between first appearance of symptoms and diagnosis, location of the primary tumor, tumor volume, or response to postoperative treatment. All but one patient with incomplete surgery had tumor recurrence within 2 to 23 months. CONCLUSION: Choroid plexus carcinoma has a very poor prognosis when surgery is incomplete. Aggressive surgical resection of the tumor is necessary for survival. Although chemotherapy gives promising responses, local control remains the main challenge, and "second look" surgery has to be considered for patients with incomplete resection.

[Reliability of the response rate in oncology: analysis of the causes for variation]. / Fiabilité des taux de réponses en oncologie: analyse des causes de variation.

We evaluated the impact of an evaluation committee (EC) on patients' overall response status in a large multicenter trial in oncology. We identified reasons for disagreements between investigators and the EC. The Cancer Renal Cytokine (CRECY) study was a French multicenter trial that tested cytokine therapy in 489 patients with metastatic renal cell carcinoma. Objective response (OR) evaluation included medical imaging and was studied according to international guidelines. A blinded peer review of all responders and litigious cases was performed by an EC. Major disagreements occurred in 43% and minor disagreements in 10.5% of the reviewed files. The number of significant tumor responses was reduced by 23.2% after review by the EC. Reasons for disagreements included errors in tumor measurements, errors in selection of measurable targets, intercurrent diseases, and radiologic technical problems. These reasons for disagreements are analyzed and discussed. We conclude that all therapeutic trial results should be reviewed by peer analysis of all presumed responders by an EC. International guidelines for response evaluation should be updated by including more reliable methods of measurements and definition of minimal imaging procedures.

[Assessment of procarbazine, vincristine and lomustine association (PCV protocol) in oligodendroglioma and mixed glioma]. / Evaluation de l'association procarbazine, vincristine et lomustine (PCV) dans l'oligodendrogliome et les gliomes mixtes.

Effective chemotherapy using PCV (procarbazine, lomustine and vincristine) has been documented in anaplastic oligodendrogliomas and oligoastrocytomas. A pilot study using PCV was conducted for relapsing patients with anaplastic oligodendrogliomas and oligoastrocytomas. Preliminary results are reported. Fourteen patients were enrolled. All received at least two courses of PCV and were evaluable for response. Eleven patients (78%) responded to chemotherapy with complete responses in 2 patients. Response was more obvious regarding contrast enhanced areas than volumes changes (11 responses versus 7). A story of seizure was the main clinical prognostic factor for response. All toxicities were manageable and no treatment related death occurred. Chemotherapy is an effective treatment in aggressive oligodendrogliomas. Further studies must assess the role of chemotherapy in the multidisciplinary management of oligodendroglioma.

[Treatment with cytokines of metastatic kidney cancer: the Lyon experience]. / Traitement par les cytokines du cancer du rein métastatique: l'expérience lyonnaise.

Between October 1987 and June 1992, 244 patients with metastatic renal carcinoma were referred to our Institute. One hundred and sixty-nine were included in immunotherapy protocols. The 40 most recent patients were included in the ongoing multicentric randomised Crecy study. The previous patients were treated with IL2 as a continuous infusion or high doses intravenous IL2 combined with alpha interferon (IFN) or a combination of IL2 and IFN as subcutaneous low doses. Some patients received as rescue treatment a combination of IL2 with Tumor Necrosis Factor (TNF). First line immunotherapy with cytokines gave 14-25% response rates in these patients with 5-10% of complete persistent remissions. The most intensive regimen was responsible for the most severe toxicity as well as the highest response rate. TNF does not appear to be of great concern since its systemic administration induced important limiting toxicities. This work emphasizes the need for prospective studies in order to evaluate the optimal mode and schedule of treatment as well as to investigate the impact of immunotherapy on survival.

[Unusual relapse for neuroblastoma. Case of an intracranial relapse]. / Rechute inhabituelle de neuroblastome. A propos d'une récidive intracrânienne.

The usual sites of initial metastatic deposits in neuroblastoma are osteo-medullary. With modern therapies including megatherapy and hematopoietic rescue, prolonged survival is obtained. However, unusual metastatic sites are more and more often described during the prolonged evolution of these patients such as brain metastases. A case of isolated intracerebral metastatic relapse is reported here in a patient who had received 4 months before a megatherapy in first complete remission. Pathogeny and therapeutical implications are discussed.

[Gastro-intestinal stromal tumors: news and comments]. / Tumeurs stromales du tractus digestif: actualités 2003.

Gastrointestinal stromal tumors (GIST) are rare tumors occuring at all levels of the gastrointestinal tract, whose estimated incidence may be close to 2 new cases per 100 000 persons per year. GIST derive from the interstital cells of Cajal (ICC) responsible for the motility of the GI tract, or from a common precursor of ICC and of the smooth muscle cells of the digestive tract. GIST cells express the c-kit protoconcogene under an activated form, either mutated or constitutively activated, as well as the CD34 Ag. Mutations of the KIT gene is an early event in the process of transformation in these tumors. Until recently, GIST were not recognized as a distinct entity among soft tissue sarcoma. It is now clear that conventional chemotherapy is generally inactive in this tumor, surgery being the only efficient therapeutic modality even in patients with advanced disease. Rapidly accruing phase I, II and III trials in the USA and Europe (EORTC) have demonstrated since 2000 that imatinib mesylate (STI571) is an active agent in GIST with an initial response rate of 70 % and 10 % only of primary refractory tumors, yelding an improved overall survival as compared to historical series. Resistance are now being observed however. GIST has become the first model of a solid tumor treated efficiently by a treatment targetting the initial genetic alteration of the disease. Numerous question regarding the integration of this treatment with surgery and the long term outcome of these patients still remain to be answered however.