Javier Martín

Deletions Affecting Codons 557-558 of the c-KIT Gene Indicate a Poor Prognosis in Patients With Completely Resected Gastrointestinal Stromal Tumors: A Study by the Spanish Group for Sarcoma Research (GEIS)

PURPOSEnTo explore the prognostic value of mutations in c-KIT and PDGFR-alpha genes with respect to relapse-free survival (RFS) in patients with gastrointestinal stromal tumors (GIST). We have investigated the prognostic relevance of the type and position of the mutations, in addition to other clinicopathologic factors, in a large series of patients with GIST.nnnMETHODSnFor this study, 162 patients were selected according to the following criteria: completely resected tumors with negative margins attended between 1994 and 2001; no metastasis at diagnosis; tumor larger than 2 cm, c-KIT-positive immunostaining; and no other primary tumors.nnnRESULTSnThe median follow-up was 42 months for patients free of recurrence. Mutations were detected in 96 tumors (60%): 82 cases involving c-KIT and 14 cases involving PDFGR-alpha. Univariate analysis demonstrated the following as poor prognostic factors for RFS: tumors larger than 10 cm (P < .0001); mitotic count higher than 10 mitoses per 50 high-power fields (P < .0001); high risk index (P < .0001); intestinal GIST location (P = .0041); high cellularity (P < .0001); tumor necrosis (P < .0001); deletions affecting exon 11 (P = .0007); and deletions affecting codons 557 to 558 (P < .0001). After the multivariate analysis, only the high risk index (relative risk [RR], 12.36), high cellularity (RR, 3.97), and deletions affecting codons 557 to 558 of c-KIT (RR, 2.57) corresponded to independent prognostic factors for RFS in GIST patients.nnnCONCLUSIONnDeletions affecting codons 557 to 558 are relevant for the prognosis of RFS in GIST patients. This critical genetic alteration should be considered to be a new prognostic stratification variable for randomized trials exploring imatinib mesylate in the adjuvant setting in GIST patients.

Clinicopathologic profile of gastrointestinal stromal tumors (GISTs) with primary KIT exon 13 or exon 17 mutations: a multicenter study on 54 cases

Gastrointestinal stromal tumors (GISTs) are mesenchymal neoplasms driven by oncogenic, mutational activation of KIT or platelet-derived growth factor receptor α (PDGFRA). GIST-specific KIT or PDGFRA mutations have been linked to tumor location, tumor cell morphology and clinical behavior. The purpose of this study was to evaluate the clinicopathologic profile of GISTs that have KIT exon 13 or exon 17 mutations. Through the collaboration of several GIST research groups, we gathered 54 cases from the pre-imatinib era that had such primary mutations. From our observations and those in the literature, we estimate that the frequency of these mutations is no higher than 1–2%. Almost all (32 of 33, 97%) of the KIT exon 13 mutations were the 1945A>G substitution leading to Lys642Glu. A majority (15 of 21, 71.4%) of the KIT exon 17 mutations were the 2487T>A substitution leading to Asn822Lys. Demographic and clinicopathologic data were available for 26 and 14 KIT exon 13 and exon 17 mutant GISTs, respectively. Median age and male to female ratio were similar to ones reported in other GIST studies. Small intestinal tumors were two times more frequent than gastric ones among KIT exon 17 mutants. Also, intestinal tumors were slightly overrepresented among KIT exon 13 mutants when compared with population-based studies. The majority of KIT exon 13 or exon 17 mutants had a spindle-cell morphology and only a few had epithelioid features. Tumor size varied from 1.2 to 25u2009cm and average mitotic rates were 9.5 and 4.2 for KIT exon 13 and exon 17 mutants, respectively. Gastric KIT exon 13 mutant GISTs tend to be slightly larger and more aggressive than gastric GISTs in average, whereas the behavior of small intestinal GISTs with KIT exon 13 mutations does not differ from other small intestinal GISTs. The latter is also true for all KIT exon 17 mutant GISTs.

A phase II trial of temozolomide as a 6-week, continuous, oral schedule in patients with advanced soft tissue sarcoma: a study by the Spanish Group for Research on Sarcomas.

The objective of this study was to evaluate the activity and toxicity of temozolomide given as an extended schedule in patients with advanced sarcoma.

Efficacy of Sequential High-Dose Doxorubicin and Ifosfamide Compared With Standard-Dose Doxorubicin in Patients With Advanced Soft Tissue Sarcoma: An Open-Label Randomized Phase II Study of the Spanish Group for Research on Sarcomas

PURPOSEnTo assess the progression-free survival (PFS) and antitumor response to standard-dose doxorubicin compared with sequential dose-dense doxorubicin and ifosfamide in first-line treatment of advanced soft tissue sarcoma.nnnPATIENTS AND METHODSnPatients with measurable advanced soft tissue sarcoma, Eastern Cooperative Oncology Group (ECOG) performance status (PS) < 2, between the ages 18 and 65 years, and with adequate bone marrow, liver, and renal function were entered in the study. The stratifications were: ECOG PS (0 v 1), location of metastases, and potentially resectable disease. Patients were randomly assigned to either doxorubicin 75 mg/m(2) given as a bolus injection every 3 weeks for 6 cycles (arm A) or doxorubicin at 30 mg/m(2) per day for 3 consecutive days once every 2 weeks for 3 cycles followed by ifosfamide at 12.5 g/m(2) delivered by continuous infusion over 5 days once every 3 weeks for 3 cycles with filgastrim or pegfilgastrim support (arm B).nnnRESULTSnBetween December 2003 and September 2007, 132 patients were entered onto the study. Febrile neutropenia, asthenia, and mucositis were more frequent in the arm B. The interim preplanned analysis for futility allowed the premature closure. Objective responses were observed in 23.4% of assessable patients in arm A and 24.1% in arm B. PFS was 26 weeks in the arm A and 24 weeks in arm B (P = .88). Overall survival did not differ between the two therapeutic arms (P = .14).nnnCONCLUSIONnSingle-agent doxorubicin remains the standard treatment in fit patients with advanced soft tissue sarcoma.

Phase II trial of first-line high-dose ifosfamide in advanced soft tissue sarcomas of the adult: A study of the Spanish Group for Research on Sarcomas (GEIS)

BACKGROUNDnThe agent Ifosfamide (IFOS) is active against soft tissue sarcomas (STS), and patients who progress to IFOS at doses < or = 10 g/m2 show remissions when exposed to high-dose ifosfamide (HDI) (i.e., doses > 10 g/m2), which supports a dose-response relationship for this drug. Because of a lack of first-line studies in adult STS patients, we decided to test the activity and toxicity of HDI in a phase II trial.nnnPATIENTS AND METHODSnForty-eight patients were enrolled in the study. IFOS was administered at a dose of 14 g/m2 by continuous infusion over six days every four weeks. Granulocyte-macrophage colony-stimulating factor (GM-CSF) at 5 micrograms/kg/day for 10 consecutive days was systematically administered after an episode of neutropenic fever or a delay in hematologic recovery. Patients were treated until progression or the occurrence of severe toxicity, and surgical rescue was attempted when possible.nnnRESULTSnSix pathology-established complete remissions and 11 partial remissions were observed in 45 assessable patients with a response rate of 37.7% (95% CI: 25.5%-50%). Grade 3-4 toxicity (% of cycles) was noted by hemoglobin (17%), leukocyte (75%), granulocyte (75%) and platelet (13%) counts in 158 evaluable cycles. GM-CSF was administered to 28 patients, and 25 suffered one or more episodes of neutropenic fever. Renal toxicity was mild and reversible with some degree of tubular and glomerular dysfunction detected in up to 60% of patients. Grade 3 CNS toxicity was observed in 32% of patients but only one required interruption of therapy. Sixty-four per cent of the patients had asthenia grade 2-3 and 20% were excluded from the study due to excessive toxicity. There was one treatment-related death.nnnCONCLUSIONSnHDI is an active drug in first-line therapy against adult STS. Different administration schedules should be evaluated in an attempt to improve its therapeutic index.

Yondelis® (ET-743, Trabectedin) sensitizes cancer cell lines to CD95-mediated cell death: New molecular insight into the mechanism of action

Trabectedin, a naturally occurring substance isolated from the Caribbean marine invertebrate Ecteinascidia turbinata, is the active compound of the antitumor drug Yondelis®. The mechanism of action of Trabectedin has been attributed to interactions with the minor groove of the DNA double helix, thereby affecting transcription of different genes involved in DNA repair and thus facilitating lethal DNA strand breaks. Nevertheless, the existence of other clinically important molecular mechanisms has not yet been fully explored. In this paper we demonstrate how Yondelis®, apart from activating the caspase-8-dependent cascade of apoptosis, sensitizes cancer cells to Fas-mediated cell death at achievable concentrations similar to those found in the plasma of patients. In addition we show that the facilitated apoptosis activated through the Fas death receptor, is associated with a significant increase of membrane Fas/FasL, as well as the modulation of accessory proteins regulating this route, such as FLIP (L) or Akt. Thus, our results propose that the sensitization of the death receptor pathway is an essential mechanism amplifying the cytotoxic properties of Yondelis® that could explain the hepatotoxicity observed in patients treated with this drug. Finally, we also show how the use of dexamethasone as a prophylactic agent that protects against hepatotoxicity induced by Yondelis® may also inhibit some of the cytotoxic properties described in this work. The study of this important mechanism of action should set up the basis for reassessing clinical therapy with Yondelis® in order to improve antitumor treatment outcome.

Inhibition of c-Myc Down-Regulation by Sustained Extracellular Signal-Regulated Kinase Activation Prevents the Antimetabolite Methotrexate- and Gemcitabine-Induced Differentiation in Non-Small-Cell Lung Cancer Cells

Non-small-cell lung cancer (NSCLC) is characterized by severe resistance to chemotherapy. Here, we demonstrate that A549 adenocarcinoma cells permanently differentiate with the antimetabolites methotrexate (MTX) and gemcitabine (GE) when blocking the resistance mechanism that normally counteracts this process. MTX (1-10 μM) and GE (1 μM) induced growth arrest accompanied by sustained extracellular signal-regulated kinase (ERK1/2) phosphorylation and moderate reduction of c-Myc levels after 96 h, whereas only a low percentage of the cells differentiated. Combination with the mitogen-activated protein kinase kinase (MEK) inhibitor 1,4-diamino-2,3-dicyano-1,4-bis-(methylthio)butadiene (U0126) reduced MTX- or GE-induced ERK1/2 over-phosphorylation, nearly abolished c-Myc expression, and provoked radical morphological changes in all cells. Besides the appearance of multilamellar bodies and intracellular cytokeratin reorganization, modulation of molecular markers occurred in a manner consistent with differentiation (gelsolin, +300%; surfactant protein A and C, -70%). Similar to U0126, c-Myc inactivation with specific small interfering RNA initiated differentiation only in the presence of MTX, demonstrating that inhibition of the mitogen-activated protein kinase/ERK pathway alone or down-regulation of c-Myc is not sufficient to induce this process. It is noteworthy that withdrawal of antitumoral drugs and U0126 neither reversed differentiation nor reactivated proliferation. Our results reveal that maintenance of a certain threshold of c-Myc expression through sustained ERK1/2 activation represents a molecular mechanism that confers resistance to antimetabolite-induced differentiation in A549 cells, and provide a novel molecular basis for therapeutic strategies based on irreversible differentiation of cancer cells using conventional chemotherapeutic antimetabolites in combination with inhibitors of the MEK/ERK pathway or c-Myc.

Light Protocol and Buffer Management for Automatically Recovering Streaming Sessions in WiFi Mobile Telephones

The media streaming technology is very appropriate for client applications running on mobile telephones due to its limited memory and bandwidth. A serious problem that has not been fully solved is the control of temporary client disconnections due to the lack of coverage, because it causes the closing of the current session and forces the opening of a new one with the corresponding loss of efficiency. Moreover, the software for developing a mobile telephone streaming client is in its infancy: The implementation of robust software that automatically recovers a streaming session is very difficult. The aim of this paper is to show a new light protocol and buffer management to efficiently support wireless multimedia communication disruptions and to recover the streaming session automatically. We are the first to obtain a working software in a commercial mobile telephone supporting disruption and maintaining constant the input throughput to the streaming client.

Phase II Trial of Doxorubicin Plus Escalated High-Dose Ifosfamide in Patients With Advanced Soft Tissue Sarcomas of the Adult: A Study of the Spanish Group for Research on Sarcomas (GEIS)

Background. To explore the tolerance and the activity of high-dose ifosfamide (IFOS) combined with doxorubicin (DXR) at 50 mg/m2 every 4 weeks in patients with soft tissue sarcomas. Methods. DXR was given IV bolus and IFOS by continuous infusion at 2 g/m2/day. Initial IFOS dose (12 g/m2) was adjusted to 10, 13, or 14 g/m2 according to toxicity. Results. Seventy patients received 277 cycles (median 3 cycles, range 1–10), 34% with IFOS dose increased, 30% decreased, and 48% delivered at 12 g/m2. Toxicity grade 4 occurred on granulocytes (67% of patients) or platelets (19%), 54% had febrile neutropenia, 31% grade 3/4 asthenia, and 26% abandoned the study due to toxicity. Three toxic deaths occurred. In 57 non-GIST patients objective activity was 45.6% (95% CI, 32 to 58%). Conclusion. At least 4 cycles were tolerated by 71% of patients, most receiving DXR 50 mg/m2 plus IFOS 10–12 g/m2, with substantial toxicity.

Doxorubicin (DXR) and prolonged infusion gemcitabine (GMC) as first-line treatment in advanced soft tissue sarcomas (STS). A phase II trial of the Spanish Group for Research in Sarcomas (GEIS)

9033 Background: Results from a previous phase I trial (ASCO 2003, abst.3317) demonstrated MTD for GMC 800 mg/m2 by 10 mg/m2/min perfusion associated to DXR 60 mg/m2 Methods: April02 to December03 36 patients were included in a phase II trial of first-line treatment in advanced STS with DX at 60 mg/m2 (d 1), followed by GMC 800 mgr/m2 administered in 80 minutes (d 1,8) every 3 weeks.nnnRESULTSn36 patients ECOG 0-2, metastatic/unresectable STS entered the trial. Results from 23 patients: male/ female 13/10; ECOG 0 = 5 pts, 1 = 15 pts, 2 = 3 pts. Median age 56 (23-76)y.nnnHISTOLOGYnLipos. 6, MFH 4, Leiomio 2, other 11. Primary tumor: extremities 8, retroperitoneal 7, uterine 2, truncal 2, other 4. A median of 6 (1-9) and a total of 93 cycles (cy) were administered. Toxicity by patient (23): neutropenia grade(G)IV 7 (30%), GIII 9 (39%); anemia GIII 4 (17%), GII 7 (30%); thrombocytopenia GIV 2 (8%), GIII 3 (13%), GII 4 (17%) pts. Neutropenic fever in 5 (21%) pts. Grade III/IV mucositis in 14 (60%) pts. Toxicity by cy (93): neutropenia GIV 16 (17%), GIII 24 (26%), GII 10 (10%); anemia GIII 7 (7%), GII 18 (19%) of cy; GIII/IV thrombocytopenia in 8 (8%); Neutropenic fever in 8 (8%) cy. Mucositis GII in 12 (13%) and GIII/IV in 17 (18%) of cy. Dose reduction was performed in 47/93 cy. There were no toxic deaths. In 20 evaluable patients 2 PR and 13 SD were obtained.nnnCONCLUSIONSnDXR and GMC delivered by prolonged infusion has some activity in advanced STS. Hematological toxicity and mucositis are relevant and limiting adverse effects. No significant financial relationships to disclose.