RESUMO
Point mutations emerge as one of the rate-limiting steps in tumor response to small molecule inhibitors of protein kinases. Here we characterized the response of the MET mutated variants, V1110I, V1238I, V1206L and H1112L to the small molecule SU11274. Our results reveal a distinct inhibition pattern of the four mutations with IC(50) values for autophosphorylation inhibition ranging between 0.15 and 1.5muM. Differences were further seen on the ability of SU11274 to inhibit phosphorylation of downstream MET transducers such as AKT, ERK, PLCgamma and STAT3 and a variety of MET-dependent biological endpoints. In all the assays, H1112L was the most sensitive to SU11274, while V1206L was less affected under the used concentration range. The differences in responses to SU11274 are discussed based on a structural model of the MET kinase domain.
Assuntos
Indóis/farmacologia , Mutação/efeitos dos fármacos , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-met/química , Proteínas Proto-Oncogênicas c-met/genética , Sulfonamidas/farmacologia , Animais , Western Blotting , Adesão Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Camundongos , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Mutação/genética , Células NIH 3T3 , Proteína Oncogênica v-akt/metabolismo , Fosfolipase C gama/metabolismo , Fosforilação/efeitos dos fármacos , Conformação Proteica , Proteínas Proto-Oncogênicas c-met/metabolismo , Fator de Transcrição STAT3/metabolismo , Cicatrização/efeitos dos fármacosRESUMO
PURPOSE: To evaluate the consecutive treatment results regarding pterygium recurrence and the efficacy of exclusive strontium-/yttrium-90 beta-irradiation for primary and recurrent pterygia and to analyze the functional outcome. PATIENTS AND METHODS: Between October 1974 and December 2005, 58 primary and 21 recurrent pterygia were exclusively treated with strontium-/yttrium-90 beta-irradiation with doses ranging from 3,600 to 5,500 cGy. The follow-up time was 46.6 +/- 26.7 months, with a median of 46.5 months. RESULTS: The treatment led to a size reduction in all pterygia (p < 0.0001). Neither recurrences nor side effects were observed during therapy and follow-up in this study. Best-corrected visual acuity increased (p = 0.0064). Corneal astigmatism was reduced in recurrent pterygia (p = 0.009). CONCLUSION: Exclusive strontium-/yttrium-90 beta-irradiation of pterygia is a very efficient and well-tolerated treatment, with remarkable aesthetic and rehabilitative results in comparison to conventional treatments, especially for recurrent lesions which have undergone prior surgical excision.
Assuntos
Partículas beta/uso terapêutico , Braquiterapia/instrumentação , Pterígio/radioterapia , Radioisótopos de Estrôncio/uso terapêutico , Radioisótopos de Ítrio/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Astigmatismo/radioterapia , Estética , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dosagem Radioterapêutica , Recidiva , Retratamento , Acuidade Visual/efeitos da radiaçãoRESUMO
Abnormal activation of DNA repair pathways by deregulated signaling of receptor tyrosine kinase systems is a compelling likelihood with significant implications in both cancer biology and treatment. Here, we show that due to a potential substrate switch, mutated variants of the receptor for hepatocyte growth factor Met, but not the wild-type form of the receptor, directly couple to the Abl tyrosine kinase and the Rad51 recombinase, two key signaling elements of homologous recombination-based DNA repair. Treatment of cells that express the mutated receptor variants with the Met inhibitor SU11274 leads, in a mutant-dependent manner, to a reduction of tyrosine phosphorylated levels of Abl and Rad51, impairs radiation-induced nuclear translocation of Rad51, and acts as a radiosensitizer together with the p53 inhibitor pifithrin-alpha by increasing cellular double-strand DNA break levels following exposure to ionizing radiation. Finally, we propose that in order to overcome a mutation-dependent resistance to SU11274, this aberrant molecular axis may alternatively be targeted with the Abl inhibitor, nilotinib.
Assuntos
Reparo do DNA , Genes abl , Variação Genética , Mutação , Rad51 Recombinase/genética , Transporte Ativo do Núcleo Celular , Animais , Benzotiazóis/metabolismo , Dano ao DNA , Indóis/farmacologia , Camundongos , Células NIH 3T3 , Fosforilação , Piperazinas/farmacologia , Rad51 Recombinase/fisiologia , Radiossensibilizantes/farmacologia , Sulfonamidas/farmacologia , Tolueno/análogos & derivados , Tolueno/metabolismo , Tirosina/químicaRESUMO
PURPOSE: Integration of high-risk papillomavirus DNA has been considered an important step in oncogenic progression to cervical carcinoma. Disruption of the human papillomavirus (HPV) genome within the E2 gene is frequently a consequence. This study investigated the influence of episomal viral DNA on outcome in patients with advanced cervical cancer treated with primary radiotherapy. METHODS AND MATERIALS: Paraffin-embedded biopsies of 82 women with locally advanced cervical cancer could be analyzed for HPV infection by multiplex polymerase chain reaction (PCR) by use of SPF1/2 primers. E2-gene intactness of HPV-16-positive samples was analyzed in 3 separate amplification reactions by use of the E2A, E2B, E2C primers. Statistical analyses (Kaplan-Meier method; log-rank test) were performed for overall survival (OS), disease-free survival (DFS), local progression-free survival (LPFS), and distant metastases-free survival (DMFS). RESULTS: Sixty-one (75%) of 82 carcinomas were HPV positive, 44 of them for HPV-16 (72%). Seventeen of the 44 HPV-16-positive tumors (39%) had an intact E2 gene. Patients with a HPV-16-positive tumor and an intact E2 gene showed a trend for a better DFS (58% vs. 38%, p = 0.06) compared with those with a disrupted E2 gene. A nonsignificant difference occurred regarding OS (87% vs. 66%, p = 0.16) and DMFS (57% vs. 48%, p = 0.15). CONCLUSION: E2-gene status may be a promising new target, but more studies are required to elucidate the effect of the viral E2 gene on outcome after radiotherapy in HPV-positive tumors.
Assuntos
Proteínas de Ligação a DNA/genética , Papillomavirus Humano 16/genética , Proteínas Oncogênicas Virais/genética , Infecções por Papillomavirus/virologia , Neoplasias do Colo do Útero/virologia , Primers do DNA/genética , DNA Viral/isolamento & purificação , Feminino , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Análise de Sobrevida , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/radioterapia , Integração ViralRESUMO
BACKGROUND AND PURPOSE: Daily use of conventional electronic portal imaging devices (EPID) for organ tracking is limited due to the relatively high dose required for high quality image acquisition. We studied the use of a novel dose saving acquisition mode (RadMode) allowing to take images with one monitor unit per image in prostate cancer patients undergoing intensity-modulated radiotherapy (IMRT) and tracking of implanted fiducial gold markers. PATIENTS AND METHODS: Twenty five patients underwent implantation of three fiducial gold markers prior to the planning CT. Before each treatment of a course of 37 fractions, orthogonal localization images from the antero-posterior and from the lateral direction were acquired. Portal images of both the setup procedure and the five IMRT treatment beams were analyzed. RESULTS: On average, four localization images were needed for a correct patient setup, resulting in four monitor units extra dose per fraction. The mean extra dose delivered to the patient was thereby increased by 1.2%. The procedure was precise enough to reduce the mean displacements prior to treatment to < o =0.3 mm. CONCLUSIONS: The use of a new dose saving acquisition mode enables to perform daily EPID-based prostate tracking with a cumulative extra dose of below 1 Gy. This concept is efficiently used in IMRT-treated patients, where separation of setup beams from treatment beams is mandatory.
Assuntos
Eletrônica Médica/instrumentação , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/instrumentação , Radioterapia de Intensidade Modulada , Ouro , Humanos , Masculino , Próstata/efeitos da radiação , Neoplasias da Próstata/diagnóstico por imagem , Radiografia , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Resultado do TratamentoRESUMO
OBJECTIVE: The objective of this study was to determine the MRI characteristics of Merkel cell carcinoma, with an emphasis on histologic correlation. MATERIALS AND METHODS: The demographic information about 15 patients from our institution and their MRI examinations were retrospectively reviewed by three musculoskeletal radiologists by consensus for lesion location and intrinsic characteristics. The study group was composed of three women and 12 men who ranged in age from 48 to 87 years, with a mean age of 75 years. Histology results of resected specimens were reviewed in all cases and were correlated with imaging. RESULTS: MRI showed skin thickening, subcutaneous reticular stranding (n = 9, 60%); multiple anatomically aligned subcutaneous soft-tissue masses, representing lymphatic tumor nodules (n = 5, 33%); lymph node enlargement with fine, compressed, retained fatty tissue (n = 5, 33%); nodal necrosis (n = 1); and perifascial and intramuscular metastases (n = 2). Histology confirmed the lymphatic nature of the soft-tissue Merkel cell tumors. CONCLUSION: Patients with Merkel cell tumors may present at imaging with subcutaneous lymphatic reticular stranding, multiple subcutaneous masses, and lymph node metastases. Often there is massive lymph node enlargement with fine, compressed, retained fatty tissue.
Assuntos
Carcinoma de Célula de Merkel/patologia , Imageamento por Ressonância Magnética/métodos , Neoplasias Cutâneas/patologia , Neoplasias de Tecidos Moles/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
BACKGROUND AND PURPOSE: Extracapsular spread (ECS) is frequent, but the specific sites of relapse are seldom given in the literature. In this study it was evaluated, if ECS might be an indicator for axillary irradiation. PATIENTS AND METHODS: After a retrospective review of pathology reports, the information about ECS was available in 254 lymph node-positive patients: ECS was absent in 34% (ECS-negative; n = 87) and present in 66% (ECS-positive; n = 167). All patients were irradiated locally, 78 patients got periclavicular and 74 axillary irradiation (median total dose: 50.4 Gy). 240/254 patients (94.5%) received systemic treatment/s. Mean follow-up was 46 months. RESULTS: The regional relapse rate was 4.6% without ECS versus 9.6% with ECS. The 5-year axillary relapse-free survival was 100% in ECS-negative and 90% in ECS-positive patients (p = 0.01), whereas corresponding values for periclavicular relapse-free survival (with ECS: 91% +/- 4%; without ECS: 94% +/- 3%; p = 0.77) and local relapse-free survival (with ECS: 86% +/- 4%; without ECS: 91% +/- 3%; p = 0.69) were not significantly different. chi(2)-tests revealed a high correlation of ECS with T-stage, number of positive lymph nodes and progesterone receptor status, comparisons with estrogen receptor, grade, or age were not significant. In multivariate analysis number of positive lymph nodes was solely significant for regional failure. Dividing the patients into those with one to three and those with four or more positive lymph nodes, ECS lost its significance for axillary failure. CONCLUSION: ECS was accompanied by an enhanced axillary failure rate in univariate analysis, which was no longer true after adjusting for the number of positive lymph nodes.
Assuntos
Neoplasias da Mama/radioterapia , Linfonodos/efeitos da radiação , Metástase Linfática , Adulto , Idoso , Idoso de 80 Anos ou mais , Axila/efeitos da radiação , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Terapia Combinada , Interpretação Estatística de Dados , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Metástase Linfática/radioterapia , Mastectomia Radical Modificada , Mastectomia Segmentar , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Dosagem Radioterapêutica , Receptores de Estrogênio/análise , Receptores de Progesterona/análise , Estudos Retrospectivos , Análise de Sobrevida , Fatores de Tempo , Falha de TratamentoRESUMO
BACKGROUND AND PURPOSE: To evaluate long term results and to demonstrate safety and efficacy of non-surgical, exclusive strontium-/yttrium-90 beta irradiation of non-operated pterygia. PATIENTS AND METHODS: Between March 1977 and April 1999, 43 patients with 54 primary pterygia were treated with an exclusive strontium-/yttrium-90 beta-irradiation up to a total dose of 50 Gy divided in four fractions with one week apart. All patients were referred from the same ophthalmologist. The average follow-up were 112(+/-88 months (range, 12-321 months), median 96 months. RESULTS: The patients were referred with early symptomatic manifestations of pterygia with a mean horizontal diameter of 1.6+/-0.7 mm (range, 0.5-4.5 mm), which shrank to a mean diameter of 0.9+/-0.6 mm (range, 0-2.5 mm) after irradiation (P<0.005). There was a reduction of size in every pterygium, none of the 54 pterygia developed a recurrent growth and there were no patient with any late side effect. Following the strontium-/yttrium-90 application the process came up with an obliteration of the vessels, which resulted in a grey, thin and avascular pannus. CONCLUSIONS: Strontium-/yttrium-90 beta-irradiation as an exclusive, non-surgical treatment for early pterygia provides a significant reduction of the size of the irradiated pterygia, is a safe and effective therapy to prevent a recurrence and can be performed without late side effects.
Assuntos
Pterígio/radioterapia , Lesões por Radiação , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pterígio/patologia , Radioisótopos de Estrôncio/uso terapêutico , Resultado do Tratamento , Radioisótopos de Ítrio/uso terapêuticoRESUMO
PURPOSE: Prospective study to evaluate consecutive treatment results and to demonstrate safety and efficacy of nonsurgical, exclusive strontium-/yttrium-90 beta-irradiation of nonoperated pterygia. PATIENTS AND METHODS: Between November 1999 and March 2002, 20 patients with 21 primary pterygia and six patients with recurrent pterygia after former surgery were treated with exclusive strontium-/yttrium-90 irradiation up to a total dose of 3,600 cGy (six fractions) and 4,800 cGy (eight fractions), respectively. All patients were referred from a single institution. The mean follow-up is 35.6 +/- 7.3 months (range 24-48 months). RESULTS: Prior to irradiation the mean horizontal diameter of all pterygia was 2.6 mm and shrank to a mean diameter of 1.6 mm after treatment (p = 0.0011, Student's t-test). The treatment led to a reduction in size of all 21 primary and all six recurrent pterygia. Visual acuity reached a value of 0.73 before and 0.82 after treatment. This improvement was not significant in Student's t-test (p = 0.12). The visual acuity did not decrease in any patient, complications were not observed, and in none of the 27 pterygia a recurrence developed CONCLUSION: Exclusive strontium-/yttrium-90 irradiation of the early and moderately advanced pterygium is a very efficient and very well-tolerated method of treatment. As to the therapeutic management, it is suggested to apply beta-irradiation prior to the development of an astigmatism-relevant pterygium, which requires excision.
Assuntos
Pterígio/radioterapia , Estrôncio/uso terapêutico , Radioisótopos de Ítrio/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Pterígio/patologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND AND PURPOSE: Analyses of permanent brachytherapy seed implants of the prostate have demonstrated that the use of a preplan may lead to a considerable decrease of dosimetric implant quality. The authors aimed to determine whether the same drawbacks of preplanning also apply to high-dose-rate (HDR) brachytherapy. PATIENTS AND METHODS: 15 patients who underwent two separate HDR brachytherapy implants in addition to external-beam radiation therapy for advanced prostate cancer were analyzed. A pretherapeutic transrectal ultrasound was performed in all patients to generate a preplan for the first brachytherapy implant. For the second brachytherapy, a subset of patients were treated by preplans based on the ultrasound from the first brachytherapy implant. Preplans were compared with the respective postplans assessing the following parameters: coverage index, minimum target dose, homogeneity index, and dose exposure of organs at risk. The prostate geometries (volume, width, height, length) were compared as well. RESULTS: At the first brachytherapy, the matching between the preplan and actual implant geometry was sufficient in 47% of the patients, and the preplan could be applied. The dosimetric implant quality decreased considerably: the mean coverage differed by -0.11, the mean minimum target dose by -0.15, the mean homogeneity index by -0.09. The exposure of organs at risk was not substantially altered. At the second brachytherapy, all patients could be treated by the preplan; the differences between the implant quality parameters were less pronounced. The changes of prostate geometry between preplans and postplans were considerable, the differences in volume ranging from -8.0 to 13.8 cm(3) and in dimensions (width, height, length) from -1.1 to 1.0 cm. CONCLUSION: Preplanning in HDR brachytherapy of the prostate is associated with a substantial decrease of dosimetric implant quality, when the preplan is based on a pretherapeutic ultrasound. The implant quality is less impaired in subsequent implants of fractionated brachytherapy.
Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Radioterapia Assistida por Computador/métodos , Humanos , Masculino , Neoplasias da Próstata/patologia , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Resultado do Tratamento , UltrassonografiaRESUMO
BACKGROUND: We compared concomitant cisplatin and irradiation with radiotherapy alone as adjuvant treatment for stage III or IV head and neck cancer. METHODS: After undergoing surgery with curative intent, 167 patients were randomly assigned to receive radiotherapy alone (66 Gy over a period of 6 1/2 weeks) and 167 to receive the same radiotherapy regimen combined with 100 mg of cisplatin per square meter of body-surface area on days 1, 22, and 43 of the radiotherapy regimen. RESULTS: After a median follow-up of 60 months, the rate of progression-free survival was significantly higher in the combined-therapy group than in the group given radiotherapy alone (P=0.04 by the log-rank test; hazard ratio for disease progression, 0.75; 95 percent confidence interval, 0.56 to 0.99), with 5-year Kaplan-Meier estimates of progression-free survival of 47 percent and 36 percent, respectively. The overall survival rate was also significantly higher in the combined-therapy group than in the radiotherapy group (P=0.02 by the log-rank test; hazard ratio for death, 0.70; 95 percent confidence interval, 0.52 to 0.95), with five-year Kaplan-Meier estimates of overall survival of 53 percent and 40 percent, respectively. The cumulative incidence of local or regional relapses was significantly lower in the combined-therapy group (P=0.007). The estimated five-year cumulative incidence of local or regional relapses (considering death from other causes as a competing risk) was 31 percent after radiotherapy and 18 percent after combined therapy. Severe (grade 3 or higher) adverse effects were more frequent after combined therapy (41 percent) than after radiotherapy (21 percent, P=0.001); the types of severe mucosal adverse effects were similar in the two groups, as was the incidence of late adverse effects. CONCLUSIONS: Postoperative concurrent administration of high-dose cisplatin with radiotherapy is more efficacious than radiotherapy alone in patients with locally advanced head and neck cancer and does not cause an undue number of late complications.
Assuntos
Antineoplásicos/uso terapêutico , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/radioterapia , Cisplatino/uso terapêutico , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/radioterapia , Adolescente , Adulto , Idoso , Antineoplásicos/efeitos adversos , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Cisplatino/efeitos adversos , Terapia Combinada/efeitos adversos , Intervalo Livre de Doença , Feminino , Seguimentos , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Radioterapia/efeitos adversos , Risco , Taxa de SobrevidaRESUMO
Reflex otalgia is a predictive and prognostic parameter for local control in patients with oropharynx carcinoma. Can a morphologic correlate of this important symptom be detected by MRI? Thirty-six patients were prospectively evaluated by MRI before radical radiotherapy. Sixteen patients had reflex otalgia; 20 did not. The oropharynx and adjacent regions were analyzed. Alteration was defined as effacement of anatomical structures, signal alteration or enhancement after contrast medium administration. The chi(2)-test was used to compare categorical parameters. In patients with reflex otalgia, alteration of the following structures innervated by the glossopharyngeal nerve were found significantly more often: nasopharynx, hard palate, superior constrictor pharyngis muscle, palatine tonsil, palatopharyngeus muscle, palatoglossus muscle, stylopharyngeus muscle, hyoglossus muscle and preepiglottic space. No difference was found for the muscles of mastication, levator and tensor veli palatini muscles, styloglossus muscle, genioglossus muscle, intrinsic muscles of the tongue, digastric muscles, mucosal surface of the lateral and posterior pharyngeal wall, uvula, valleculae, parapharyngeal space and larynx. An alteration of structures innervated by the glossopharyngeal nerve was visualized on MRI significantly more often when reflex otalgia was present. Involvement of structures innervated by other cranial nerves did not show the same association with ear pain.
Assuntos
Carcinoma de Células Escamosas/patologia , Dor de Orelha/diagnóstico , Dor de Orelha/fisiopatologia , Nervo Glossofaríngeo/fisiopatologia , Neoplasias Orofaríngeas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/complicações , Carcinoma de Células Escamosas/radioterapia , Dor de Orelha/etiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Neoplasias Orofaríngeas/complicações , Neoplasias Orofaríngeas/patologia , Orofaringe/inervação , Orofaringe/patologia , Valor Preditivo dos Testes , Prognóstico , Estudos ProspectivosRESUMO
BACKGROUND: Hypoxia-inducible factor 1 alpha (hif-1alpha) furnishes tumor cells with the means of adapting to stress parameters like tumor hypoxia and promotes critical steps in tumor progression and aggressiveness. We investigated the role of hif-1alpha expression in patients with node-positive breast cancer. METHODS: Tumor samples from 77 patients were available for immunohistochemistry. The impact of hif-1alpha immunoreactivity on survival endpoints was determined by univariate and multivariate analyses, and correlations to clinicopathological characteristics were determined by cross-tabulations. RESULTS: hif-1alpha was expressed in 56% (n = 43/77) of the patients. Its expression correlated with progesterone receptor negativity (P = 0.002). The Kaplan-Meier curves revealed significantly shorter distant metastasis-free survival (DMFS) (P = 0.04, log-rank) and disease-free survival (DFS) (P = 0.04, log-rank) in patients with increased hif-1alpha expression. The difference in overall survival (OS) did not attain statistical significance (5-year OS, 66% without hif-1alpha expression and 55% with hif-1alpha expression; P = 0.21). The multivariate analysis failed to reveal an independent prognostic value for hif-1alpha expression in the whole patient group. The only significant parameter for all endpoints was the T stage (T3/T4 versus T1/T2: DMFS, relative risk = 3.16, P = 0.01; DFS, relative risk = 2.57, P = 0.03; OS, relative risk = 3.03, P = 0.03). Restricting the univariate and multivariate analyses to T1/T2 tumors, hif-1alpha expression was a significant parameter for DFS and DMFS. CONCLUSIONS: hif-1alpha is expressed in the majority of patients with node-positive breast cancer. It can serve as a prognostic marker for an unfavorable outcome in those with T1/T2 tumors and positive axillary lymph nodes.
Assuntos
Neoplasias da Mama/patologia , Metástase Linfática , Proteínas de Neoplasias/fisiologia , Fatores de Transcrição/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos Hormonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/radioterapia , Estudos de Coortes , Terapia Combinada , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Docetaxel , Doxorrubicina/administração & dosagem , Epirubicina/administração & dosagem , Feminino , Fluoruracila/administração & dosagem , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia , Tábuas de Vida , Metotrexato/administração & dosagem , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Estadiamento de Neoplasias , Paclitaxel/administração & dosagem , Prednisona/administração & dosagem , Prognóstico , Receptores de Progesterona/análise , Risco , Análise de Sobrevida , Tamoxifeno/uso terapêutico , Taxoides/administração & dosagem , Fatores de Transcrição/análise , Vincristina/administração & dosagemRESUMO
Point mutations constitute a major mode of oncogenic activation of the Met receptor tyrosine kinase. Met is aberrantly activated in many types of human malignancies and its deregulated activity is correlated with aggressive tumor traits such as abnormal proliferation and survival, leading to tumor growth, local invasion and metastasis. Here we report that the Met kinase inhibitor SU11274 differentially affects the kinase activity and subsequent signaling of various mutant forms of Met. Two Met variants tested, M1268T and H1112Y, were potently inhibited by 2 microM SU11274, while two other variants, L1213V and Y1248H, remained resistant under similar experimental conditions. Inhibition of the kinase altered cell proliferation, morphology and motility, while cells containing resistant mutants appeared unaffected by the compound. The basis for the sensitivity or resistance to SU11274 is discussed in terms of the position of the mutations predicted from a homology model.
Assuntos
Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Mutação , Piperazinas/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores , Sulfonamidas/farmacologia , Animais , Antineoplásicos/farmacologia , Ciclo Celular , Divisão Celular , Linhagem Celular , Movimento Celular , Sobrevivência Celular , DNA/química , Progressão da Doença , Relação Dose-Resposta a Droga , Citometria de Fluxo , Regulação da Expressão Gênica , Camundongos , Modelos Moleculares , Células NIH 3T3 , Metástase Neoplásica , Transdução de SinaisRESUMO
It is still an open debate whether tumor emboli in dermal lymphatics without inflammatory signs represent a similar bad prognosis like inflammatory breast cancer. We evaluated the prognostic role of dermal lymphatic invasion (DLI) in breast cancer with (DLI + ID) or without (DLI w/o ID) inflammatory disease (ID). From August 1988 to January 2000, 42 patients with DLI were irradiated. Twenty-five were classified as pT4, 13 out of them as pT4d (inflammatory disease); the 17 remaining patients had 1 T1c, 12 T2 and 4 T3 cancers with DLI. Axillary dissection revealed node-positive disease in 39/41 patients (median, 9 positive nodes). Thirty-eight out of 42 patients received adjuvant systemic treatment(s). After a mean follow-up of 33 months, 22/42 patients (52%) are disease-free. The actuarial 3-year disease-free survival is 50% (DLI w/o ID, 61%; DLI + ID, 31%; p < 0.03); the corresponding overall survival was 69% (DLI w/o ID, 87%; DLI + ID, 37%; p = 0.005). The presence or absence of ID was the only significant parameter for all endpoints in multivariate analyses. Dissemination occurred in 19 (45%), local relapse in 7 (n = 17%) and regional failure in 4 (10%). Nine patients (21%) had contralateral breast cancer/relapse. Despite the same histopathologic presentation, DLI w/o ID offered a significantly better disease-free survival and overall survival than ID. The finding of dermal lymphatic tumor invasion predicts a high probability for node-positive disease.
Assuntos
Neoplasias da Mama/diagnóstico , Metástase Linfática/diagnóstico , Prognóstico , Neoplasias Cutâneas/diagnóstico , Neoplasias Cutâneas/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Humanos , Inflamação , Pessoa de Meia-Idade , Análise Multivariada , Fatores de TempoRESUMO
Aberrant signalling through the hepatocyte growth factor/scatter factor receptor Met has been implicated in various aspects of the development of human cancer including the promotion of tumour invasion, angiogenesis and metastasis. Moreover, experimental data indicate that activation of the Met receptor may be involved in cellular resistance towards antineoplastic treatments such as chemotherapy and ionizing radiation. We determined the prevalence and clinical impact of the Met-activating mutation Y1253D in patients with squamous cell cancer of the oropharynx treated by radical radiotherapy. To screen archival tissue for the presence of a low-abundance point mutation, we developed a sensitive screening method using real-time polymerase chain reaction along with peptide nucleic acid-based DNA clamping and melting curve analysis. By this approach, Met Y1253D was detected in tumours of 15 out of 138 patients (10.9%). Both univariate and multivariate survival analysis revealed Met Y1253D to be significantly associated with impaired local tumour control. Our results provide evidence that the Met-activating mutation Y1253D is present in a notable subset of patients with oropharyngeal cancer and indicate that it may interfere with radioresponsiveness of these tumours, supporting the notion of aberrant Met signalling as a potential target for radiosensitization.
Assuntos
Frequência do Gene , Neoplasias de Células Escamosas/genética , Neoplasias Orofaríngeas/genética , Proteínas Proto-Oncogênicas c-met/genética , Substituição de Aminoácidos , Humanos , Neoplasias de Células Escamosas/radioterapia , Neoplasias Orofaríngeas/radioterapia , Mutação Puntual , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas c-met/metabolismo , Transdução de Sinais/genética , TemperaturaRESUMO
PURPOSE: To evaluate if locoregional radiotherapy (RT) versus local irradiation only can alter the pattern of failure in breast cancer patients with extranodal invasion. PATIENTS AND METHODS: From 08/1988 to 06/1998, 81 patients with extranodal invasion were treated with adjuvant RT (median total dose: 50.4 Gy), 46/81 only locally, 35/81 loco regionally due to presumed adverse parameters. The mean number of resected (positive) lymph nodes was 17 (seven). 78 patients received adjuvant systemic treatment(s). RESULTS: Patients treated with locoregional RT had significantly more often lymphatic vessel invasion (LVI; 63% vs. 28%; p = 0.003), T3/T4 tumors (43% vs. 17%; p = 0.014), and four or more positive lymph nodes (91% vs. 46%; p < 0.001) than patients irradiated only locally. Disease progression occurred in 24/81 patients (locoregional RT: 26% vs. local RT: 33%). The above risk factors were highly significant of worse outcome. Despite their overrepresentation in the locoregional RT group, no difference was found between both groups in regard to disease-free survival (DFS; p = 0.83) and overall survival (OS; p = 0.56), suggesting that regional RT was able to counterbalance the increased risk. There was even a trend toward a better 3-year DFS, 61% in locoregional RT and 37% in local RT, in the subgroup of patients with four or more positive lymph nodes. In a Cox regression model, higher T-stage, four or more positive lymph nodes, and LVI remained significant. For DFS and distant metastasis-free survival (DMFS), the absence of estrogen receptors and the omission of regional RT were also significant. CONCLUSION: Our data suggest that the addition of regional RT might be beneficial in selected subgroups of patients with extranodal invasion and other poor prognostic factors.
Assuntos
Neoplasias da Mama/radioterapia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Neoplasias da Mama/cirurgia , Terapia Combinada , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Excisão de Linfonodo , Metástase Linfática , Mastectomia Segmentar , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia , Dosagem Radioterapêutica , Radioterapia Adjuvante , Estudos Retrospectivos , Fatores de Risco , Análise de Sobrevida , Fatores de TempoRESUMO
PURPOSE: In the early stages of cervical cancer treated with surgery alone, hypoxia-inducible factor-1alpha (hif-1alpha) expression is prognostic for overall survival. Because hypoxia plays an important role in radiation resistance, we investigated hif-1alpha expression in cervical cancer treated with local radical radiotherapy (RT). METHODS AND MATERIALS: Between 1990 and 1998, 91 patients with squamous cell or adenocarcinoma of the uterine cervix were treated with external beam RT with and without brachytherapy. Biopsies from 78 patients were available for immunohistochemistry. The impact of the immunoreactivity of hif-1alpha in regard to survival end points was determined by univariate and multivariate analyses. Correlations with clinicopathologic characteristics were determined by cross-tabulations. RESULTS: Hif-1alpha was expressed in 73 (94%) of 78 patients. It was closely linked to the pretreatment hemoglobin level (p = 0.04, r = -0.22, Spearman correlation test). The Kaplan-Meier curves showed a significantly shorter local progression-free survival (p = 0.04, log-rank) and overall survival (p = 0.01, log-rank) and a trend for shorter disease-free survival (p = 0.15) for patients with increased hif-1alpha expression. The multivariate analyses revealed hif-1alpha expression to be an independent factor for overall survival (p = 0.02). CONCLUSION: Hif-1alpha is expressed in the vast majority of patients with advanced cervical cancer and had a prognostic significance. A weak but significant correlation was noted with pretreatment hemoglobin level.
Assuntos
Adenocarcinoma/metabolismo , Carcinoma de Células Escamosas/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/metabolismo , Fatores de Transcrição , Neoplasias do Colo do Útero/metabolismo , Adenocarcinoma/mortalidade , Adenocarcinoma/patologia , Adenocarcinoma/radioterapia , Análise de Variância , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/radioterapia , Hipóxia Celular/fisiologia , Intervalo Livre de Doença , Feminino , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Resultado do Tratamento , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/patologia , Neoplasias do Colo do Útero/radioterapiaRESUMO
BACKGROUND: Has a conscious exclusion of the contralateral major salivary glands (parotid, submandibular, and sublingual glands) a significant impact on the milieu of the oral cavity (saliva flow, pH, buffer capacity, and colonisation with Streptococcus mutans) in patients with ENT tumors receiving radical radiotherapy? PATIENTS AND METHODS: 20 consecutive consenting patients with ENT tumors were evaluated once before, weekly during, and 6 weeks after the end of treatment in regard to saliva flow, ph, buffer capacity, and colonisation with Streptococcus mutans. In 13 patients the major salivary glands on both sides were included in the treated volume, in seven patients the treatment portals excluded consciously the contralateral major salivary glands. RESULTS: The stimulated saliva flow decreases already during the 1st week of radiotherapy, the decrease follows the dose exponentially; the saliva flow is further reduced in the weeks after the end of treatment. The effect is less pronounced in patients with sparing of contralateral major salivary glands. The majority of patients with unilateral sparing of the major salivary glands retain the baseline value of buffer capacity, whereas buffer capacity of all patients with inclusion of all major salivary glands is markedly reduced with 20 Gy already, without signs of recovery when treatment has stopped. With unilateral salivary gland sparing the pH always remains basic, in bilaterally irradiated patients the pH changes from a mean of 7.3 to 5.8 during treatment. The colonisation with Streptococcus mutans varies little in both groups during the radiotherapy; after the end of therapy, it is higher in bilaterally irradiated patients. CONCLUSIONS: The conscious arrangement of irradiation portals in order to spare contralateral major salivary glands in patients with radical radiotherapy of ENT tumors has a significant influence on the oral environment: the stimulated saliva flow is higher, the buffer capacity retains the baseline value, the saliva pH remains basic, and the colonisation with Streptococcus mutans is reduced.