RESUMO
In animal models, growth of tumors and their metastases is dependent on factors that stimulate vessel formation (angiogenesis). Most clinical studies confirm the importance of angiogenesis for cancer growth in patients. Recent studies on circulating angiogenic factors in patients have focused on serum vascular endothelial growth factor (VEGF) levels in a variety of cancer types. We measured serum VEGF concentrations and blood counts in 27 breast cancer patients during each of 6 cycles of chemotherapy with doxorubicin and cyclophosphamide supported by granulocyte macrophage colony-stimulating factor. Serum VEGF concentrations highly correlated with platelet counts during chemotherapy (r = 0.8; P < 0.01). In particular, during the first treatment cycle, after an initial episode of thrombocytopenia, a strong platelet rebound coincided closely with a serum VEGF peak (r = 0.9; P < 0.01). In addition, plasma VEGF concentrations from 15 other cancer patients and 30 healthy volunteers were 5- to 8-fold lower than their corresponding serum VEGF concentrations (P < 0.001). Activation of platelets increased the VEGF content 8-10 times. These findings demonstrate that VEGF is released by platelets during serum preparation. In this study, we found evidence for VEGF transport by platelets, indicating that serum VEGF concentrations reflect mainly platelet counts rather than tumor burden in cancer patients, as reported earlier. Platelets, known to be important for wound healing, have also been reported to contribute to metastasis formation and tumor growth in animal models. Indeed, tumors can be regarded as never-healing wounds. Our data suggest that platelets may have a stimulating role on angiogenesis-dependent tumor growth through their function as transporters of VEGF.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Plaquetas/fisiologia , Neoplasias da Mama/sangue , Neoplasias da Mama/tratamento farmacológico , Fatores de Crescimento Endotelial/sangue , Linfocinas/sangue , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ciclofosfamida/administração & dosagem , Doxorrubicina/administração & dosagem , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Humanos , Ativação Plaquetária , Valores de Referência , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
The effect of long-term administration of granulocyte-macrophage colony-stimulating factor (GM-CSF) on dendritic cell (DC) activation and survival in patients with locally advanced breast cancer (LABC) was studied. To this end, the number of activated DC (i.e. positive for the marker S100) in tumour-draining lymph nodes (TDLN) was determined and compared between LABC patients receiving neoadjuvant chemotherapy with GM-CSF (n=52) or without GM-CSF (n=11), and a control group of chemonaïve breast cancer patients (n=10). A significantly higher mean percentage of S100+ DC in the TDLN of the GM-CSF-treated patients (9.9%) was found compared with each of the respective control groups (5.3 and 5.1%, P=0.002). Moreover, intrapatient comparison before and after treatment showed that the percentage of S100+ DC significantly increased over the course of the GM-CSF treatment (P=0.018). In a univariate survival analysis with a median follow-up of 64 months, relatively high percentages of S100+ DC (> or =8%) were associated with a longer disease-free survival (DFS) (P=0.078). In patients with a high tumour load, where immunosuppressed conditions generally prevail, long-term administration of GM-CSF may thus contribute to survival through enhanced DC activation and consequently improved chances of effective antitumour immunity.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Células Dendríticas/efeitos dos fármacos , Fator Estimulador de Colônias de Granulócitos e Macrófagos/administração & dosagem , Adulto , Idoso , Axila , Sobrevivência Celular , Quimioterapia Adjuvante , Células Dendríticas/imunologia , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Metástase Linfática , Pessoa de Meia-Idade , Proteínas S100/análise , Resultado do TratamentoRESUMO
This study investigates which factors influence the response of administered recombinant human erythropoietin (Re-HuEPO) with respect to the increase of haemoglobin in patients with end-stage renal disease. Pharmacokinetic parameters of administered Re-HuEPO in patients with end-stage renal disease and considerable differences in the amount of Re-HuEPO required ("Re-HuEPO-need") to obtain an increase of haemoglobin, revealed a pattern of dose-dependent first-order elimination without significant interindividual differences between the patients. As variable immunological inhibitors of erythropoietin are also absent, the administered Re-HuEPO seems to be equally available to the erythron in the various patients. In vitro incubation experiments with bone marrow cells show that the sera from patients with end-stage renal disease contain inhibitors of the erythropoietin-induced stimulation of bone marrow cells. As the patients' sera differ with regard to the degree of inhibition of erythropoietin bioactivity, this inhibition may also be responsible for the interindividual differences in amount of erythropoietin required. Besides a reduced endogenous production of erythropoietin, these inhibitors of the bioactivity of erythropoietin may also contribute to the pathogenesis of anaemia in patients with chronic renal failure.
Assuntos
Eritropoetina/antagonistas & inibidores , Falência Renal Crônica/terapia , Adulto , Idoso , Anemia/etiologia , Medula Óssea/metabolismo , Eritropoetina/administração & dosagem , Eritropoetina/sangue , Feminino , Hemoglobinas/biossíntese , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/antagonistas & inibidoresRESUMO
BACKGROUND: Neoadjuvant chemotherapy is increasingly applied in patients with locally advanced cancers of many tumour types. Usually three cycles of chemotherapy are administered to reduce the tumour size prior to local therapy, and another three cycles thereafter. The chemotherapy certainly contributes to the improved outcome of this approach. However, biological factors within the primary tumour have been neglected, while they might also contribute to the eradication of micrometastases. We believe that the neoadjuvant strategy can be improved by optimally exploiting certain biological factors inherent to the primary tumour. In a group of patients with locally advanced breast cancer (LABC) we studied this concept. Recently we described the clinical results of this phase II study in patients with LABC treated with neoadjuvant chemotherapy plus granulocyte-macrophage colony-stimulating factor (GM-CSF). A remarkable good response and survival was seen. In contrast to other studies we applied six cycles of neoadjuvant treatment in stead of a sandwich approach consisting of three cycles before and three cycles after local therapy, leaving the primary tumour and draining lymph nodes in situ for a prolonged period. In addition, GM-CSF was administered as a haematopoietic growth factor in stead of granulocyte colony-stimulating factor (G-CSF) as GM-CSF has also immuno-stimulating properties. Our findings definitely warrant further exploration of prolonged neoadjuvant systemic treatment in combination with GM-CSF in other high risk primary tumours. HYPOTHESES: The promising results of our study may be attributable to two potential biological phenomena. Firstly, the conservation of the tumour and its draining lymph nodes may prove to be an essential part of this approach, with particular emphasis on the activation of tumour specific cytotoxic T cells. Secondly, circulating angiogenesis inhibitors originating from the primary tumour may enhance the effect of chemotherapy on micrometastases.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Quimioterapia Adjuvante , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Humanos , Neovascularização Patológica/prevenção & controleRESUMO
This study was done to arrive at a fast and reliable protocol for assessment of fractional volumes of immunohistochemically stained dendritic cells in lymph nodes. Twenty axillary lymph nodes of patients with locally advanced breast cancer were immuno-histochemically stained with an S100 antibody. Fractional volumes of dendritic cells were assessed by stereology based quantitative immunohistochemistry using an interactive video overlay system including an automated microscope. The gold standard percentage of dendritic cells was the fractional volume of S100 stained cells in 500 fields systematically spread over the whole lymph node. Then, in a computer simulation, different sample sizes (1-200 fields of vision) were tested and the coefficient of variation (CV) for each sample size was calculated. The CV dropped with increasing sample size. A sample size of 100 fields of vision appeared to be optimal. Intra- and interobserver reproducibility appeared to be good (correlation coefficients of 0.95 and 0.86, respectively) when re-analyzing the cases with the established protocol. In conclusion, a fast and reliable assessment of the fractional volume of dendritic cells in lymph nodes is possible with semi-automated quantitative immuno-histochemistry. This method will form the base for further clinical studies into the immunological response in lymph nodes of patients with locally advanced breast cancer.
Assuntos
Neoplasias da Mama/patologia , Células Dendríticas/química , Processamento de Imagem Assistida por Computador/métodos , Linfonodos/patologia , Proteínas S100/análise , Simulação por Computador , Feminino , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Imuno-Histoquímica , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Tamanho da AmostraRESUMO
BACKGROUND: Neoadjuvant chemotherapy improves survival in patients with locally advanced breast cancer (LABC). Usually three to four cycles of conventional-dose neoadjuvant chemotherapy are administered prior to local therapy, and another three cycles thereafter. In an attempt to improve results, we increased the dosages and applied GM-CSF, which, besides being a hematopoietic growth factor, has become increasingly known for its immunostimulatory effects, which might enhance the antitumor effect. METHODS: Forty-two patients with stage IIIA or IIIB breast cancer were treated with doxorubicin (A) (90 mg/m2) and cyclophosphamide (C) (1,000 mg/m2) at three-weekly intervals. In the second and fourth cycle a 10% dose reduction of both agents was applied. On the second day GM-CSF 250 micrograms/m2/day was started and given for 10 days. Initially, some patients were treated with < or = four cycles, but as the study progressed and toxicity appeared tolerable, six cycles were given whenever possible. After the chemotherapy, patients underwent surgery and postoperative radiotherapy. RESULTS: The response rate for the whole group to AC was 98% (95% confidence interval 94%-100%), with a clinical complete response rate of 50% (95% confidence interval 35%-65%). Six patients had a pathological complete response. Median follow-up from the start of chemotherapy is 49 months (range 10-100). The disease-free survival (DFS) at three years is 57% and the overall survival (OS) at three years is 79%. There is a significant trend for improved DFS (p = 0.0000) and OS (p = 0.0002) with increasing number of cycles. CONCLUSION: The results of the present study with neoadjuvant dose-intensive AC chemotherapy and GM-CSF compare favorably with previous studies in patients with LABC. This is most apparent in patients who received six cycles of neoadjuvant chemotherapy. We hypothesize that these encouraging results are probably related to the prolonged presence of the primary tumor, and to the long-term administration of GM-CSF with the primary tumor and axillary lymph nodes in situ. Therefore, a randomized study is warranted. We already initiated an international randomized trial in patients with LABC in order to answer two questions. First, does prolonged neoadjuvant chemotherapy result in an improved DFS and OS in comparison with the conventional approach, and secondly, what is the effect of GM-CSF in this approach in comparison with G-CSF?
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Terapia Neoadjuvante , Adulto , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Intervalos de Confiança , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Esquema de Medicação , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neutropenia/induzido quimicamente , Trombocitopenia/induzido quimicamenteRESUMO
Important therapeutic applications of genetically modified dendritic cells (DC) have been proposed; however, current vector systems have demonstrated only limited gene delivery efficacy to this cell type. By means of bispecific Abs, we have dramatically enhanced gene transfer to monocyte derived DC (MDDC) by retargeting adenoviral (Ad) vectors to a marker expressed on DC, CD40. Adenovirus targeted to CD40 demonstrated dramatic improvements in gene transfer relative to untargeted Ad vectors. Fundamental to the novelty of this system is the capacity of the vector itself to modulate the immunological status of the MDDC. This vector induces DC maturation as demonstrated phenotypically by increased expression of CD83, MHC, and costimulatory molecules, as well as functionally by production of IL-12 and an enhanced allostimulatory capacity in a MLR. In comparing this vector to other Ad-based gene transfer systems, we have illustrated that the features of DC maturation are not a function of the Ad particle, but rather a consequence of targeting to the CD40 marker. This vector approach may thus mediate not only high-efficiency gene delivery but also serve a proactive role in DC activation that could ultimately strengthen the utility of this vector for immunotherapy strategies.