Acute myeloid leukemia or myelodysplastic syndrome in randomized controlled clinical trials of cancer chemotherapy with granulocyte colony-stimulating factor: a systematic review

Therapy-related myeloid neoplasms: pathobiology and clinical characteristics

Therapy-related myeloid neoplasms (t-MNs) are serious long-term consequences of cytotoxic treatments for an antecedent disorder. t-MNs are observed after ionizing radiation as well as conventional chemotherapy including alkylating agents, topoisomerase-II-inhibitors and antimetabolites. In addition, adjuvant use of recombinant human granulocyte-colony stimulating factor may also increase the risk of t-MNs. There is clinical and biological overlap between t-MNs and high-risk de novo myelodysplastic syndromes and acute myeloid leukaemia suggesting similar mechanisms of leukaemogenesis. Human studies and animal models point to a prominent role of genetic susceptibilty in the pathogenesis of t-MNs. Common genetic variants have been identified that modulate t-MN risk, and t-MNs have been observed in some cancer predisposition syndromes. In either case, establishing a leukaemic phenotype requires acquisition of somatic mutations - most likely induced by the cytotoxic treatment. Knowledge of the specific nature of the initiating exposure has allowed the identification of crucial pathogenetic mechanisms and for these to be modelled in vitro and in vivo. Prognosis of patients with t-MNs is dismal and at present, the only curative approach for the majority of these individuals is haematopoietic stem cell transplantation, which is characterized by high transplant-related mortality rates. Novel transplantation strategies using reduced intensity conditioning regimens as well as novel drugs - demethylating agents and targeted therapies - await clinical testing and may improve outcome. Ultimately, individual assessment of genetic risk factors may translate into tailored therapies and establish a strategy for reducing t-MN incidences without jeopardizing therapeutic success rates for the primary disorders.

Prophylactic and therapeutic strategies in chemotherapy-induced neutropenia

INTRODUCTION

Neutropenia poses a serious threat to patients on chemotherapy. It exposes them to the risk of infection--including potentially fatal infections--and also leads to delays in treatment and reductions in dose intensity, which can compromise the possibility of a favorable outcome.

AREAS COVERED

The use of granulocyte colony-stimulating factors (G-CSF) and antibiotics to prevent febrile neutropenia (FN) and to ameliorate cancer chemotherapy-induced myelosuppression is discussed, based on a systematic search of Pubmed for clinical trials, reviews and meta-analysis published in the last 20 years. We consider that the treatment of FN, with the emphasis on careful attention to the patient, prompts antibiotic therapy and good hospital care.

EXPERT OPINION

We would argue that antibiotic prophylaxis should be offered routinely to patients receiving cytotoxic chemotherapy for acute leukemia and for patients with solid tumors and lymphoma receiving high-dose chemotherapy. In patients undergoing cyclical standard-dose myelosuppressive chemotherapy, we believe that prophylaxis is indicated during the first cycle of chemotherapy in which there is an expectation of grade 4 neutropenia (< 500 neutrophils). However, although the use of antibiotics and haematopoietic growth factors may improve quality of life by reducing the risk and consequences of FN, further study of the magnitude of their effects is needed.

How I treat elderly patients with diffuse large B-cell lymphoma

Enormous progress has been made in the treatment of diffuse large B-cell lymphoma (DLBCL), mostly due to the anti-CD20 antibody rituximab. More than 50% of elderly DLBCL patients can be expected to be cured by modern immunochemotherapy. The standard chemotherapy partner of rituximab is the CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) regimen. Elderly patients need particular attention and thorough evaluation if they are suited for the standard treatment or if they are candidates for palliative treatment. Rigorous supportive care including anti-infectious prophylaxis and growth factor support are mandatory. Whether there is still a role of additive radiotherapy in the R-CHOP era is under debate. While further intensification of chemotherapy might hardly be feasible in elderly patients, dose and schedule of rituximab appear to be optimizable. Patients failing after R-CHOP are a particular challenge as are frail patients who are not fit enough for R-CHOP. Further progress can be expected from novel antibodies and small molecules that interfere with signal transduction pathways essential for the survival of the lymphoma cell. To achieve this goal, prospective trials with large numbers of patients are necessary for which the continuous commitment of patients and physicians is indispensable.

2010 update of EORTC guidelines for the use of granulocyte-colony stimulating factor to reduce the incidence of chemotherapy-induced febrile neutropenia in adult patients with lymphoproliferative disorders and solid tumours

Chemotherapy-induced neutropenia is a major risk factor for infection-related morbidity and mortality and also a significant dose-limiting toxicity in cancer treatment. Patients developing severe (grade 3/4) or febrile neutropenia (FN) during chemotherapy frequently receive dose reductions and/or delays to their chemotherapy. This may impact the success of treatment, particularly when treatment intent is either curative or to prolong survival. In Europe, prophylactic treatment with granulocyte-colony stimulating factors (G-CSFs), such as filgrastim (including approved biosimilars), lenograstim or pegfilgrastim is available to reduce the risk of chemotherapy-induced neutropenia. However, the use of G-CSF prophylactic treatment varies widely in clinical practice, both in the timing of therapy and in the patients to whom it is offered. The need for generally applicable, European-focused guidelines led to the formation of a European Guidelines Working Party by the European Organisation for Research and Treatment of Cancer (EORTC) and the publication in 2006 of guidelines for the use of G-CSF in adult cancer patients at risk of chemotherapy-induced FN. A new systematic literature review has been undertaken to ensure that recommendations are current and provide guidance on clinical practice in Europe. We recommend that patient-related adverse risk factors, such as elderly age (≥65 years) and neutrophil count be evaluated in the overall assessment of FN risk before administering each cycle of chemotherapy. It is important that after a previous episode of FN, patients receive prophylactic administration of G-CSF in subsequent cycles. We provide an expanded list of common chemotherapy regimens considered to have a high (≥20%) or intermediate (10-20%) risk of FN. Prophylactic G-CSF continues to be recommended in patients receiving a chemotherapy regimen with high risk of FN. When using a chemotherapy regimen associated with FN in 10-20% of patients, particular attention should be given to patient-related risk factors that may increase the overall risk of FN. In situations where dose-dense or dose-intense chemotherapy strategies have survival benefits, prophylactic G-CSF support is recommended. Similarly, if reductions in chemotherapy dose intensity or density are known to be associated with a poor prognosis, primary G-CSF prophylaxis may be used to maintain chemotherapy. Clinical evidence shows that filgrastim, lenograstim and pegfilgrastim have clinical efficacy and we recommend the use of any of these agents to prevent FN and FN-related complications where indicated. Filgrastim biosimilars are also approved for use in Europe. While other forms of G-CSF, including biosimilars, are administered by a course of daily injections, pegfilgrastim allows once-per-cycle administration. Choice of formulation remains a matter for individual clinical judgement. Evidence from multiple low level studies derived from audit data and clinical practice suggests that some patients receive suboptimal daily G-CSFs; the use of pegfilgrastim may avoid this problem.

Treatment of cancer in the older aged person

Cancer is a disease of aging.1 Currently 50% of all malignancies occur in individuals 65 and over1 and by the year 2030 older individuals will account for 70% of all neoplasms.With the aging of the population the management of cancer in the older person with chemotherapy is beoming increasingly common. This treatment may be safe and effective if some appropriate measures are taken, including, an assessment of the physiologic age of each patient, modification of doses according to the renal function, use of meyelopoietic growth factors prophylactically in presence of moderately toxic chemotherapy, and provision of an adequate caregiver. Cure, prolongation of survival, and symptom palliation are universal goals of medical treatment. Prolongation of active life expectancy should be added to the treatment goal of the older aged person.