Granulocyte colony-stimulating factor in the treatment of high-risk febrile neutropenia: a multicenter randomized trial

Such stuff as dreams are made on: mediator-directed therapy in sepsis

Sepsis, a life-threatening disorder that arises through the body's response to infection, is the leading cause of death and disability for patients in an intensive care unit. Advances in the understanding of the complex biological processes responsible for the clinical syndrome have led to the identification of many promising new therapeutic targets, including bacterial toxins, host-derived mediators, and downstream processes such as coagulation and the endocrine response. Diverse therapies directed against these targets have shown dramatic effects in animal models; however, in humans, their impact has been frustratingly modest, and only one agent--recombinant activated protein C--has achieved regulatory approval. This review summarizes the approaches that have been evaluated in clinical trials, explores the reasons for the discordance between biological promise and clinical reality, and points to approaches that may lead to greater success in the future.

Treatment of breast cancer with chemotherapy in combination with filgrastim: approaches to improving therapeutic outcome

Chemotherapy improves disease-free and overall survival in breast cancer, and its benefit is directly related to the percentage of the planned dose that is actually administered. In all current chemotherapeutic regimens, a substantial proportion of patients have reductions and/or delays in dosage due to side effects. In about half such cases, the delays or reductions are related to neutropenia. Overall, approximately 30% of patients have a reduction to less than 85% of the planned dosage. Women aged > or = 50 years are more likely to experience a reduction or delay in dose. Dose-intense regimens (excluding myeloablative high-dose chemotherapy) which increase the dose of chemotherapy or reduce the interval between cycles, or both, are a promising approach now under investigation. The human granulocyte colony-stimulating factor filgrastim reduces the incidence of neutropenia and facilitates adherence to full dose intensity in both standard and dose-intensified regimens. A model based on the first-cycle absolute neutrophil count nadir has been developed and validated to determine which patients should receive filgrastim. A cost benefit associated with the use of filgrastim in patients with breast cancer has been realised. This may lead to a re-evaluation of the current treatment guidelines.

Filgrastim in patients with neutropenia: potential effects on quality of life

Treatment- and disease-related neutropenia are associated with a number of negative clinical effects such as febrile neutropenia, documented infection, hospitalisation for infection-related morbidity, infection-related mortality, and decreased ability to administer the planned chemotherapy dose on schedule. Reductions or delays in dosage have the ability to jeopardise the effectiveness of treatment by lowering response rates. Not only are clinical outcomes adversely affected, but these complications can have a negative influence on patient quality of life. Filgrastim is a haematopoietic growth factor that primarily acts to stimulate the proliferation and differentiation of neutrophil progenitor cells. Filgrastim is capable of reducing the incidence and severity of neutropenia and the complications that accompany it in patients with cancer or HIV infection. Although there are few data evaluating the effect of treatment with granulocyte colony-stimulating factor on quality of life, it is assumed that the benefits would be seen through both the reduction of treatment-related complications and the enhanced potential for long-term disease control. A new, longer-acting form of filgrastim is now available that has the potential to simplify the management of neutropenia and further improve patient quality of life by decreasing the number of necessary injections. Additional prospective controlled trials that contain quality-of-life issues as endpoints are needed.

Colony-stimulating factors for the management of neutropenia in cancer patients

Neutropenia and its subsequent infectious complications represent the most common dose-limiting toxicity of cancer chemotherapy. Febrile neutropenia (FN) occurs with common chemotherapy regimens in 25 to 40% of treatment-naive patients, and its severity depends on the dose intensity of the chemotherapy regimen, the patient's prior history of either radiation therapy or use of cytotoxic treatment, and comorbidities. The occurrence of FN often causes subsequent chemotherapy delays or dose reductions. It may also lengthen hospital stay, increase monitoring, diagnostic and treatment costs, and reduce patient quality of life. A decade after their introduction, colony-stimulating factors (CSFs) such as granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) are now an integral part of the prevention of potentially life-threatening FN; however, only G-CSF has US Food and Drug Administration approval for use in chemotherapy-induced neutropenia. These adjunctive agents accelerate formation of neutrophils from committed progenitors, thereby reducing the duration and severity of neutropenia. Important uses of CSFs in oncology are prevention of FN after chemotherapy, treatment of febrile neutropenic episodes and support following bone marrow transplantation, and collection of CSF-mobilised peripheral blood progenitor cells. G-CSF is used more frequently than GM-CSF for all of these indications because of fewer associated adverse effects. Clinical trials to date have not demonstrated a significant effect on overall survival or disease-free survival, which is most likely to be due to small sample size and lack of power to prove effect. However, they have demonstrated clinical utility in allowing the delivery of planned chemotherapy dose on schedule, an important clinical goal especially in curative tumour settings. The high cost of these agents limits their widespread use. Current American Society of Clinical Oncology guidelines recommend primary prophylaxis, or first cycle use, with CSFs being confined to patients with > or = 40% risk of FN, which may include elderly patients and other high-risk patients. In addition to the risk of FN, primary prophylaxis should also be considered if the patient has risk factors that place them in the Special Circumstances category. These risk factors may include decreased immune function in patients who are already at an increased risk of infection and pre-existing neutropenia due to disease, extensive prior chemotherapy, or previous irradiation to the pelvis or other areas containing large amounts of bone marrow. Future studies are needed to better define the patients most likely to benefit from CSF therapy, both for prophylaxis and as an adjunct to antibiotics for treatment of FN. Other potential uses include combination therapy with stem cell factors and other cytokines to boost progenitor cell development, maintaining dose intensity of salvage therapy in metastatic cancer patients, and application in patients with pneumonia, Crohn's fistulas, diabetic foot infections and a variety of other infectious conditions.

Economic evaluations of granulocyte colony-stimulating factor: in the prevention and treatment of chemotherapy-induced neutropenia

The prevailing uncertainty about the pharmacoeconomic positioning of granulocyte colony-stimulating factor (G-CSF) in the prevention and treatment of chemotherapy-induced febrile neutropenia has resulted in a number of pharmacoeconomic evaluations published in the past 10 years. These studies vary considerably regarding the approaches used and the results presented. In order to contribute to a clearer pharmacoeconomic positioning of G-CSF, a systematic review of economic evaluations was carried out. The focus of the review was prophylaxis and therapy of chemotherapy-induced neutropenia in patients with cancer. A computerised bibliography search of several databases was conducted yielding 33 studies. The findings demonstrated the cost-saving potential of G-CSF in standard-dose chemotherapy to be limited, with lower costs often seen in the control group. The results of these studies were too heterogeneous to extract a clear recommendation from a cost-saving point of view. The administration of G-CSF after high-dose chemotherapy with stem cell support resulted more often in cost savings in the G-CSF group as compared with standard-dose chemotherapy, illustrating a possible cost-saving potential of G-CSF. In the treatment of established chemotherapy-induced febrile neutropenia, cost savings were found in all studies. This result is surprising but hampered by the small number of studies (n = 5) and remains to be confirmed by more rigourously designed prospective economic analyses. Despite the substantial research on this topic, the economic evaluation of G-CSF is far from being settled and needs further investigation.

Colony stimulating factors for chemotherapy induced febrile neutropenia

BACKGROUND

Febrile neutropenia is a frequent event for cancer patients undergoing chemotherapy and it is potentially a life threatening situation. The current treatment is supportive care plus antibiotics. Colony stimulating factors (CSF) are cytokines that stimulate and accelerate the production of one or more cellular lines in bone marrow. Some clinical trials addressed the question of whether the addition of CSF to antibiotics (ATB) could improve the outcomes of patients with febrile neutropenia. The results of these trials are conflicting and no definitive conclusion could be reached.

OBJECTIVES

To evaluate the safety and effectiveness of adding colony stimulating factors to ATB when treating febrile neutropenia caused by cancer chemotherapy.

SEARCH STRATEGY

The search covered the major electronic databases: CANCERLIT, EMBASE, LILACS, MEDLINE, SCI and The Cochrane Controlled Trials Register. Experts were consulted and references from the relevant articles scanned.

SELECTION CRITERIA

We looked for all randomized controlled trials (RCTs) that compare CSF plus antibiotics versus antibiotics alone for the treatment of established febrile neutropenia in adults and children.

DATA COLLECTION AND ANALYSIS

Two of the reviewers independently selected, critically appraised and extracted data from the studies. A meta-analysis of the select studies was performed, using Review Manager.

MAIN RESULTS

More than 8000 references were screened. Thirteen studies were included. The overall mortality was not influenced by the use of CSF [Odds Ratio (OR) = 0.68; 95% Confidence Interval (CI) = 0.43 to 1.08; p=0.1]. A marginally significant result was obtained for the use of CSF in reducing infection related mortality [OR= 0.51; 95% CI = 0.26 to 1.00; p=0.05], but this result was highly influenced by one study. When this study is excluded from our analysis, this possible benefit disappears [OR= 0.85; 95% CI = 0.33 to 2.20; p= 0.7]. The group of patients treated with CSF had a shorter length of hospitalization [Hazard Ratio (HR) = 0.63; 95% CI = 0.49 to 0.82; p=0.0006] and a shorter time to neutrophil recovery [HR= 0.32; 95% CI = 0.23 to 0.46; p < 0.00001].

REVIEWER'S CONCLUSIONS

The use of CSF in patients with febrile neutropenia due to cancer chemotherapy does not affect overall mortality, but reduces the amount of time spent in hospital and the neutrophil recovery period. It was not clear whether CSF has an effect on infection-related mortality.

Antibiotics and growth factors in the management of fever and neutropenia in cancer patients

The association of neutropenia and infection continues to be a major cause of morbidity and mortality in cancer patients receiving myelosuppressive chemotherapy. Prompt hospitalization and initiation of empirical intravenous broad-spectrum antibiotics has been the standard of care during the past three decades. Recently, risk-assessment models have been developed that allow the identification of febrile neutropenic patients that are at low risk for medical complications and mortality. New treatment strategies are being evaluated in this low-risk patient population to safely reduce toxicity, decrease costs, and improve quality of life. These include early shift from intravenous therapy to oral antibiotics, immediate initiation of oral empiric treatment, early hospital discharge, or outpatient care. A risk-based approach should also be applied to the use of colony-stimulating factors in this setting. Growth factors should not be routinely administered to neutropenic patients with uncomplicated febrile episodes. However, recent data support their use in populations with high-risk neutropenic fever.

Cost-benefit analysis of granulocyte colony-stimulating factor in the management of elderly cancer patients

Health care costs continue to rise, and hospitalization represents the single largest component of direct medical costs associated with cancer care. Neutropenia and its complications including febrile neutropenia (FN) remain the major dose-limiting toxicity of systemic cancer chemotherapy. The risk of FN varies considerably across treatment regimens but appears to be significantly higher among elderly patients. The colony-stimulating factors (CSFs) have been used effectively in a variety of clinical settings to prevent or treat FN and to assist patients receiving dose-intensive chemotherapy with or without stem cell support. Several randomized controlled trials (RCTs) have demonstrated the clinical efficacy of the prophylactic use of CSFs. A recently presented meta-analysis of the available RCTs has confirmed the efficacy of prophylactic CSFs. The cost of these agents, along with their large-scale clinical use, has prompted a number of economic investigations. Economic models based on measures of resource utilization derived from RCTs have provided FN risk threshold estimates for the cost-saving use of prophylactic CSF. A number of important studies concerning the clinical and economic impact of these agents in elderly cancer patients have been reported during the past year. Continuing clinical and economic evaluation along with an updating of clinical practice guidelines especially related to elderly patients is recommended because of rapid technologic and clinical advances.

Clinical trials of immunomodulatory therapies in severe sepsis and septic shock

Sepsis remains one of the leading causes of mortality in critically ill patients. Increased insight into the complexities of this disease process has resulted in the targeting of various aspects of the inflammatory response as offering potential therapeutic benefits. There have been encouraging results in the past few years. Some of the tested agents have been shown to improve mortality rates in large randomized controlled trials involving patients with severe sepsis. In this article, we discuss the positive and negative results of trials in this field; some of the possible reasons for the negative results are examined, and directions for the future are suggested.

Macrophage colony-stimulating factor (M-CSF) prevents infectious death induced by chemotherapy in mice, while granulocyte-CSF does not

To clarify the effect of granulocyte colony-stimulating factor (G-CSF) and macrophage colony-stimulating factor (M-CSF/CSF-1) on chemotherapy-induced infection, we estimated the effect of those CSFs on a mouse model under severe myelosuppression. First, we established an animal model in which 48.9% (22/45) of C3H/Hej mice died of sepsis related to severe myelosuppression after intraperitoneal administration of a single dose (9 mg/kg) of mitomycin C (MMC). G-CSF or M-CSF was administered to this model on various administration schedules after chemotherapy, and the effect of those CSFs on survival rates, peripheral blood granulocyte counts, expression of adhesion molecules (CD11a, CD11b, CD18) on granulocytes and granulocyte function (phagocytosis and superoxide anion production) were examined. In all G-CSF administration groups, peripheral blood granulocyte counts were increased, but improvements in expression of adhesion molecules such as CD11a and CD18, and granulocyte function were less marked and survival rates were not improved. Meanwhile, when M-CSF was administered from 1 to 7 days after chemotherapy, granulocyte and platelet counts were increased, and moreover, expression of adhesion molecules and granulocyte function were markedly improved. Furthermore, the survival rate was significantly improved to 77.8% (28/36) compared with the MMC group (P < 0.05). Positive rate of blood culture examination at 7 days after chemotherapy in the M group was 0%, and was significantly lower than that in the G group (40%) and the MMC group (40%) (P < 0.05). These results demonstrated that it is important not only to increase the granulocyte counts, but also to improve granulocyte functions for preventing infection under myelosuppression after chemotherapy.