Role of granulocyte and granulocyte-macrophage colony-stimulating factors in the treatment of small-cell lung cancer: a systematic review of the literature with methodological assessment and meta-analysis

Small Cell Lung Cancer, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Small Cell Lung Cancer (SCLC) provide recommended management for patients with SCLC, including diagnosis, primary treatment, surveillance for relapse, and subsequent treatment. This selection for the journal focuses on metastatic (known as extensive-stage) SCLC, which is more common than limited-stage SCLC. Systemic therapy alone can palliate symptoms and prolong survival in most patients with extensive-stage disease. Smoking cessation counseling and intervention should be strongly promoted in patients with SCLC and other high-grade neuroendocrine carcinomas. The "Summary of the Guidelines Updates" section in the SCLC algorithm outlines the most recent revisions for the 2022 update, which are described in greater detail in this revised Discussion text.

Hematopoietic growth factors and tumor angiogenesis

Angiogenesis is regulated by numerous "classic" factors such as vascular endothelial growth factor (VEGF) and many other endogenous "non-classic"peptides, including erythropoietin (Epo), and granulocyte-/granulocyte macrophage colony stimulating factor (G-/GM-CSF). The latter play an important regulatory role in angiogenesis, especially under pathological conditions and constitute a crosslink between angiogenesis and hematopoiesis. This article reviews studies on the ability of hematopoietic cytokines to affect several endothelial cell functions in tumor angiogenesis. These findings in all these studies support the hypothesis formulated at the beginning of this century that a common ancestral cell, the hemangioblast, gives rise to cells of both the endothelial and the hematopoietic lineages.

Granulocyte-macrophage colony-stimulating factor increases tumor growth and angiogenesis directly by promoting endothelial cell function and indirectly by enhancing the mobilization and recruitment of proangiogenic granulocytes

Granulocyte-macrophage colony-stimulating factor has been widely used as an adjuvant therapy for cancer patients exhibiting myelosuppression induced by chemotherapy or radiotherapy. However, the effects of granulocyte-macrophage colony-stimulating factor on tumor growth, as well as its precise mechanism, are still controversial due to inconsistent evidence. This study investigated the effect of exogenous granulocyte-macrophage colony-stimulating factor on the growth of B16 melanoma, S180 sarcoma, and U14 cervical carcinoma in mice. The angiogenesis and recruitment of bone-marrow-derived cells were analyzed in tumor tissues. Interactions among granulocyte-macrophage colony-stimulating factor, bone-marrow-derived cells, and B16 tumor cells were investigated in vitro. Proangiogenic types of bone-marrow-derived cells in blood were assessed both in vivo and in vitro. The results showed that granulocyte-macrophage colony-stimulating factor markedly facilitated the growth of B16 and S180 tumors, but not U14 tumors. Granulocyte-macrophage colony-stimulating factor increased the densities of blood vessels and the number of bone-marrow-derived cells in B16 tumor tissues. The granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor cell proliferation was mediated by bone-marrow-derived cells in vitro. Meanwhile, a distinct synergistic effect on endothelial cell function between granulocyte-macrophage colony-stimulating factor and bone-marrow-derived cells was observed. After separating two types of bone-marrow-derived cells, granulocyte-macrophage colony-stimulating factor–induced enhancement of tumor growth and angiogenesis in vivo was mediated by proangiogenic cells in granulocytes, but not monocytes, with CD11b+, vascular endothelial growth factor receptor 2, and C-X-C chemokine receptor 4 granulocytes possibly involved. These data suggest that granulocyte-macrophage colony-stimulating factor contributes to the growth and angiogenesis of certain types of tumor, and these mechanisms are probably mediated by proangiogenic cells in granulocytes. Applying granulocyte-macrophage colony-stimulating factor may attenuate the antitumor effects of chemotherapy and radiotherapy in certain types of tumor.

Neutropenia and relative dose intensity on adjuvant FOLFOX chemotherapy are not associated with survival for resected colon cancer

PURPOSE

Adjuvant folinic acid, fluorouracil, and oxaliplatin (FOLFOX) chemotherapy for resected high-risk colon cancer is associated with a low risk of febrile neutropenia (FN). Neutropenia, however, is a common cause of dose modification or delay with unknown consequences on outcomes. We examined the effect of neutropenia-related and other dose-limiting toxicities and relative dose intensity of oxaliplatin and 5-FU, on relapse-free and overall survival in patients treated with FOLFOX chemotherapy for resected high-risk colon cancer.

METHODS

A chart review was conducted on patients treated at the British Columbia Cancer Agency receiving ≥1 cycle of mFOLFOX6 chemotherapy for resected stage II or III colon cancer between January 1, 2006, and December 31, 2007. Relapse-free survival (RFS) and overall survival (OS) were analyzed by the Kaplan-Meier method.

RESULTS

One hundred fourteen patients (median age 59 years, 44 % male, 98 % stage III, median follow-up 5.2 years) were included. Ninety percent of the patients experienced any dose-limiting toxicity (DLT), while 58 % of the patients had a neutropenia-related DLT. There were no documented episodes of FN. Granulocyte colony-stimulating factor (GCSF) was used in 10 % of the patients. Median relative dose intensity (RDI) was 81 and 85 % for oxaliplatin and 5-FU, respectively. Oxaliplatin and 5-FU RDI were not associated with RFS or OS when analyzed as continuous variables or categorically. Grade II or grade III/IV neutropenia compared to no neutropenia was not associated with RFS or OS.

CONCLUSIONS

DLTs affect the majority of patients on adjuvant FOLFOX for high-risk colon cancer, but RFS and OS do not appear to be affected by the associated lower RDI of oxaliplatin and 5-FU.

Medical treatment of small cell lung cancer: state of the art and new development

INTRODUCTION

Small cell lung cancer (SCLC) is a rapidly progressive disease that accounts for approximately 15% of all lung cancers. Chemotherapy remains the cornerstone of treatment of SCLC, but in the last two decades, its progress has reached a plateau. Although a significant sensitivity to chemotherapy and radiotherapy is a feature of SCLC, an early development of drug resistance unavoidable occurs during the course of the disease. Second-line treatment for relapsed patients remains a very challenging setting, with a limited clinical benefit.

AREAS COVERED

A thorough analysis of various therapeutic strategies reported in literature for SCLC treatment was performed. This review includes novel therapeutic approaches such as maintenance or consolidation treatments, new chemotherapy agents and targeted therapy.

EXPERT OPINION

Against this background, there is a desperate need for the development of novel active drugs. Among these, amrubicin has also shown more favourable antitumor activity, and is the most promising at present. Concerning targeted agents, these have failed to demonstrate effectiveness for SCLC and a better understanding of the molecular mechanisms is clearly needed. In the future, further investigations are required to clarify the role of novel anti-angiogenic or pro-apoptotic agents and hedgehog pathway inhibitors.

Effects of prophylactic hematopoietic colony stimulating factors on stem cell transplantations: meta-analysis

Hematopoietic growth factors are often given for prevention of febrile neutropenia (FN), infections, and other complications by hastening neutrophil recovery in the treatment of malignancies after high dose chemotherapy (HDCT). Although several meta-analyses have already demonstrated beneficial effects of prophylactic granulocyte colony-stimulating factors (G-CSF) administration, the effects of G-CSF have not been confirmed in cancer patients receiving stem cell transplantation (SCT) after HDCT. Therefore, we performed a statistical combination of controlled clinical trials to investigate the efficacy of prophylactic use of G-CSF in preventing the neutropenic complications associated with SCT following HDCT in cancer patients. We searched PubMed to identify potentially relevant references and finally selected seven randomized controlled trials that met all of the eligibility criteria. Our meta-analysis demonstrated that prophylactic G-CSF reduced the risk of documented infections and time to hematologic recovery manifested by days to absolute neutrophil count (ANC) ≥ 0.5 × 10(9)/L, days to ANC ≥ 1.0 × 10(9)/L, and days to platelets ≥ 20 × 10(9)/L in SCT patients with cancer following HDCT. The G-CSF treated group also showed a decrease in the length of hospital stay. However, there was no difference between G-CSF treatment group and placebo group in regard to all-cause mortality, infection-related mortality, grade 2∼4 acute graft-versus-host-disease, and episode of fever.

Extensive disease small cell lung cancer dose-response relationships: implications for resistance mechanisms

BACKGROUND

Some studies (but not others) suggested that high doses are beneficial in small cell lung cancer (SCLC). We hypothesized that dose-response curve (DRC) shape reflects resistance mechanisms.

METHODS

We reviewed published SCLC clinical trials and converted response rates into estimated mean tumor cell kill, assuming killing is proportional to reduction in tumor volume. Mean % cell survival was plotted versus planned dose intensity. Nonlinear and linear meta-regression analyses (weighted according to the number of patients in each study) were used to assess DRC characteristics.

RESULTS

Although associations between dose and cell survival were not statistically significant, DRCs sloped downward for five of seven agents across all doses and for all seven when lowest doses were excluded. Maximum mean cell kill across all drugs and doses was approximately 90%, suggesting that there may be a maximum achievable tumor cell kill irrespective of number of agents or drug doses.

CONCLUSIONS

Downward DRC slopes suggest that maintaining relatively high doses may possibly maximize palliation, although the associations between dose and slope did not achieve statistical significance, and slopes for most drugs tended to be shallow. DRC flattening at higher doses would preclude cure and would suggest that "saturable passive resistance" (deficiency of factors required for cell killing) limits maximum achievable cell kill. An example of factors that could flatten the DRC at higher doses and lead to saturable passive resistance would be presence of quiescent, noncycling cells.

Canadian supportive care recommendations for the management of neutropenia in patients with cancer

Hematologic toxicities of cancer chemotherapy are common and often limit the ability to provide treatment in a timely and dose-intensive manner. These limitations may be of utmost importance in the adjuvant and curative intent settings. Hematologic toxicities may result in febrile neutropenia, infections, fatigue, and bleeding, all of which may lead to additional complications and prolonged hospitalization. The older cancer patient and patients with significant comorbidities may be at highest risk of neutropenic complications. Colony-stimulating factors (csfs) such as filgrastim and pegfilgrastim can effectively attenuate most of the neutropenic consequences of chemotherapy, improve the ability to continue chemotherapy on the planned schedule, and minimize the risk of febrile neutropenia and infectious morbidity and mortality. The present consensus statement reviews the use of csfs in the management of neutropenia in patients with cancer and sets out specific recommendations based on published international guidelines tailored to the specifics of the Canadian practice landscape. We review existing international guidelines, the indications for primary and secondary prophylaxis, the importance of maintaining dose intensity, and the use of csfs in leukemia, stem-cell transplantation, and radiotherapy. Specific disease-related recommendations are provided related to breast cancer, non-Hodgkin lymphoma, lung cancer, and gastrointestinal cancer. Finally, csf dosing and schedules, duration of therapy, and associated acute and potential chronic toxicities are examined.

Use of Colony-Stimulating Factors for Chemotherapy-Associated Neutropenia: Review of Current Guidelines

Chemotherapy-associated neutropenia is often dose-limiting and may compromise treatment efficacy. Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage-colony-stimulating factor (GM-CSF) are increasingly used to prevent febrile neutropenia (FN) or to increase dose-density. This review discusses recent changes in treatment guidelines for chemotherapy-associated neutropenia. Primary prophylactic use of CSFs is now recommended as a treatment option at an overall risk of FN of 20%, not taking into account cost-effectiveness. To estimate the risk of FN, patient-, disease-, and treatment-related factors predicting an adverse outcome of FN have been determined. Dose-dense chemotherapy has become feasible with the use of CSFs. However, clinical benefit has been shown only for specific chemotherapy regimens in breast cancer, small cell lung cancer (SCLC), and non-Hodgkin's lymphoma (NHL), for the latter particularly for patients above 60 years of age. Strategies are being developed to tailor the use of CSFs to patients with a high risk of adverse outcome of FN.

Role of colony stimulating factors (CSFs) in solid tumours: Results of an expert panel

Febrile neutropenia is a relatively frequent event in cancer patients treated with chemotherapy. A relevant body of scientific evidence has been produced in the last 2 decades, through clinical trials addressing the efficacy of colony stimulating factors (CSFs) in the prevention and treatment of febrile neutropenia. The correct use of CSFs needs to be optimized, and several guidelines have been produced and periodically updated, in order to uniform and guide clinical practice. The aim of this review is to synthesize the most relevant clinical trials and the most important existing guidelines about the role of CSFs in solid tumours. Role of CSFs as primary prophylaxis, secondary prophylaxis and treatment of afebrile and febrile neutropenia is discussed. A special focus is dedicated to neutropenia and the use of CSFs in the treatment of the three "big killers" among the solid tumours: breast cancer, lung cancer and colorectal cancer.

Impact of allocation concealment on conclusions drawn from meta-analyses of randomized trials

BACKGROUND

Randomized trials without reported adequate allocation concealment have been shown to overestimate the benefit of experimental interventions. We investigated the robustness of conclusions drawn from meta-analyses to exclusion of such trials.

MATERIAL

Random sample of 38 reviews from The Cochrane Library 2003, issue 2 and 32 other reviews from PubMed accessed in 2002. Eligible reviews presented a binary effect estimate from a meta-analysis of randomized controlled trials as the first statistically significant result that supported a conclusion in favour of one of the interventions.

METHODS

We assessed the methods sections of the trials in each included meta-analysis for adequacy of allocation concealment. We replicated each meta-analysis using the authors' methods but included only trials that had adequate allocation concealment. Conclusions were defined as not supported if our result was not statistically significant.

RESULTS

Thirty-four of the 70 meta-analyses contained a mixture of trials with unclear or inadequate concealment as well as trials with adequate allocation concealment. Four meta-analyses only contained trials with adequate concealment, and 32, only trials with unclear or inadequate concealment. When only trials with adequate concealment were included, 48 of 70 conclusions (69%; 95% confidence interval: 56-79%) lost support. The loss of support mainly reflected loss of power (the total number of patients was reduced by 49%) but also a shift in the point estimate towards a less beneficial effect.

CONCLUSION

Two-thirds of conclusions in favour of one of the interventions were no longer supported if only trials with adequate allocation concealment were included.

Small cell lung cancer: treatment review

Lung cancer was relatively uncommon at the turn of the 20th century, and has increased in prevalence at alarming rates, particularly because of the augmented trend in smoking, so that it is now the most common cause of cancer death in the world. As almost a quarter of these cancers are of small cell in origin, it seems only appropriate that small cell lung cancer receives ample attention, rather than seemingly to have been overlooked over the last 10-15 years. Despite its generally late presentation and high risk of dissemination, it is exceptionally sensitive to chemo-radiotherapy. This review looks at the diverse options of treatment that have been used over the last few years and tries to highlight the best available. As more than 50% of patients diagnosed with lung cancer are over 70 years of age and various studies have shown that older people respond just as well as their younger counterparts, with similar results in response rates, toxicity and outcomes, it is imperative that the older generation are not disregarded in terms of age being a contraindication to therapy.

2006 update of recommendations for the use of white blood cell growth factors: an evidence-based clinical practice guideline

PURPOSE

To update the 2000 American Society of Clinical Oncology guideline on the use of hematopoietic colony-stimulating factors (CSF).

UPDATE METHODOLOGY

The Update Committee completed a review and analysis of pertinent data published from 1999 through September 2005. Guided by the 1996 ASCO clinical outcomes criteria, the Update Committee formulated recommendations based on improvements in survival, quality of life, toxicity reduction and cost-effectiveness.

RECOMMENDATIONS

The 2005 Update Committee agreed unanimously that reduction in febrile neutropenia (FN) is an important clinical outcome that justifies the use of CSFs, regardless of impact on other factors, when the risk of FN is approximately 20% and no other equally effective regimen that does not require CSFs is available. Primary prophylaxis is recommended for the prevention of FN in patients who are at high risk based on age, medical history, disease characteristics, and myelotoxicity of the chemotherapy regimen. CSF use allows a modest to moderate increase in dose-density and/or dose-intensity of chemotherapy regimens. Dose-dense regimens should only be used within an appropriately designed clinical trial or if supported by convincing efficacy data. Prophylactic CSF for patients with diffuse aggressive lymphoma aged 65 years and older treated with curative chemotherapy (CHOP or more aggressive regimens) should be given to reduce the incidence of FN and infections. Current recommendations for the management of patients exposed to lethal doses of total body radiotherapy, but not doses high enough to lead to certain death due to injury to other organs, includes the prompt administration of CSF or pegylated G-CSF.

Granulocyte colony-stimulating factor promotes tumor angiogenesis via increasing circulating endothelial progenitor cells and Gr1+CD11b+ cells in cancer animal models

Recombinant granulocyte colony-stimulating factor (G-CSF) is used for cancer patients with myelosuppression induced by chemotherapy. G-CSF has been reported to progress tumor growth and angiogenesis, but the precise mechanism of tumor angiogenesis activated by G-CSF has not been fully clarified. N-terminal-mutated recombinant human G-CSF administration increased WBCs and neutrophils in peripheral blood and reduced bone marrow stromal cell-derived factor-1 in mice, indicating its biological relevance. Mice were inoculated with Lewis lung carcinoma cells (LLCs) or KLN205 cells and treated with G-CSF. G-CSF accelerated tumor growth and intratumoral vessel density, while it did not accelerate proliferation of LLCs, KLN205 cells or human umbilical vein endothelial cells in vitro. In the absence of tumors, G-CSF did not increase circulating cells that displayed phenotypic characteristics of endothelial progenitor cells (EPCs). In the presence of tumors, G-CSF increased circulating EPCs. In addition, G-CSF treatment increased immune suppressor and endothelial cell-differentiating Gr1+CD11b+ cells in tumor-bearing mice. We conclude that G-CSF promotes tumor growth by activating tumor angiogenesis via increasing circulating EPCs and Gr1+CD11b+ cells in cancer animal models.

Extensive-stage small-cell lung cancer

Extensive-stage small-cell lung cancer (ES-SCLC) continues to be a difficult management issue. While response rates to therapy are relatively high, durable responses are rare, and long-term survival rates are dismal. Although many attempts have been made to develop new therapies, cisplatin-based combination chemotherapy remains the mainstay in the management of these patients. In this review we highlight recent developments in the treatment and management of this malignancy, and discuss future prospects in treatment.

Citation indexes do not reflect methodological quality in lung cancer randomised trials

BACKGROUND

Citation factors are applied to assess scientific work despite the fact that they were developed commercially in order to compare competing journals. The aim of the present study was to determine whether there is a relationship between citation factors and a trial's methodological quality using published randomised trials in lung cancer clinical research. Material and methods All of the randomised trials included in nine systematic reviews performed by the European Lung Cancer Working Party (ELCWP) were assessed using two quality scales (Chalmers and ELCWP).

RESULTS

One hundred and eighty-one articles were eligible. The median overall ELCWP and Chalmers quality scores were 61.8% and 49.0%, respectively, with a correlation coefficient (r(s)) of 0.74 (P <0.001). A weak association was observed between citation factors and quality scores with the respective correlation coefficients ranging from 0.18 to 0.40 (ELCWP scale) and from 0.21 to 0.38 (Chalmers scale). American authors published trials significantly more often in journals with high citation factors than European or non-American authors (P <0.0001), despite no better methodological quality. Positive trials, which were significantly more likely to be published in journals with higher citation factors, were of no better quality than negative ones.

CONCLUSION

Journals with higher citation factors do not appear to publish clinical trials with higher levels of methodological quality, at least for trials in the field of lung cancer research.