Prophylaxis of febrile neutropenia with colony-stimulating factors: the first 25 years

Secondary Neutropenias

Neutrophils are a critical component of immunity, particularly against bacteria and other pathogens, but also in inflammation and tissue repair. As a consequence, individuals with neutropenia, defined by a reduction in absolute neutrophil counts, exhibit a strong propensity to severe infections that typically present with muted symptoms. Neutropenias encompass a heterogeneous set of disorders, comprising primary neutropenias, in which specific genes are mutated, and the more common secondary neutropenias, which have diverse non-genetic causes. These include hematological and other cancers, involving both direct effects of the cancer itself and indirect impacts via the chemotherapeutic, biological agents and cell-based approaches used for treatment. Other significant causes of secondary neutropenias are non-chemotherapeutic drugs, autoimmune and other immune diseases, infections and nutrient deficiencies. These collectively act by impacting neutrophil production in the bone marrow and/or destruction throughout the body. This review describes the biological and clinical manifestations of secondary neutropenias, detailing their underlying causes and management, with a discussion of alternative and emerging therapeutic approaches.

Validation of Risk Models for Predicting Febrile Neutropenia Among Breast Cancer Patients Receiving Chemotherapy: A Real-World Study

BACKGROUND

Breast cancer patients receiving chemotherapy may develop a serious complication called febrile neutropenia (FN). We aimed to validate and compare three existing FN prediction models for breast cancer patients receiving chemotherapy in Taiwan.

PATIENTS AND METHODS

This was a retrospective observational real-world study. Data were acquired from the clinical research databases of three study hospitals. Breast cancer patients who have received at least one antineoplastic chemotherapy drug were chosen for the analysis. For evaluating the occurrence of FN, we used both broad (a body temperature above 38°C with an absolute neutrophil count (ANC) below 0.5 × 109/L or a body temperature above 38°C with a diagnosis of neutropenia) and narrow definitions (having both fever and neutropenia diagnoses or having both neutropenia and infection diagnoses). Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) were calculated for each selected FN model.

RESULTS

Among the 1903 patients identified, when the broad and narrow definitions of FN were applied, 70 (3.7%) and 60 (3.2%) patients developed FN in the first cycle, respectively. Using the broad FN definition, Aagaard's model was the highest in sensitivity (90.0%), followed by Chantharakhit's (40.0%) and Chen's (7.2%); in specificity, Chen's (93.6%) was the highest. In addition, the accuracy was highest with the Chen model (90.4%). All three models' PPVs were low, ranging from 0.5% to 4.2%, but all three models' NPVs were over 96.3%. When the narrow FN definition was used, Chantharakhit's model showed a relatively high improvement in sensitivity (53.3%) and PPV (3.9%) while negligible increases or even slight decreases were seen in the other two models and in the other performance indicators of Chantharakhit's model.

CONCLUSION

The results of this study provide important information for clinicians when selecting models to identify patients at high-risk of FN. As the model performance observed was less than satisfactory, improving the prediction ability of the models is needed.

The Potential Diagnostic Utility of SMAD4 and ACCS in the Context of Inflammation in Type 2 Diabetes Mellitus Patients

The search for new parameters for the prediction of type 2 diabetes mellitus (T2DM) or its harmful consequences remains an important field of study. Depending on the low-grade inflammatory nature of diabetes, we investigated three proteins in T2DM patients: 1-aminocyclopropane-1-carboxylate synthase (ACCS), granulocyte-colony-stimulating factor (G-CSF), and Sma Mothers Against Decapentaplegic homolog-4 (SMAD4). In brief, sixty T2DM and thirty healthy controls had their serum levels of ACCS, G-CSF, SMAD4, and insulin tested using the ELISA method. The insulin resistance (IR) parameter (HOMA2IR), beta-cell function percentage (HOMA2%B), and insulin sensitivity (HOMA2%S) were all determined by the Homeostasis Model Assessment-2 (HOMA2) calculator. The predictability of these protein levels was investigated by neural network (NN) analysis and was associated with measures of IR. Based on the results, ACCS, G-CSF, and SMAD4 increased significantly in the T2DM group compared with the controls. Their levels depend on IR status and inflammation. The multivariate GLM indicated the independence of the levels of these proteins on the covariates or drugs taken. The receiver operating characteristic area under the curve (AUC) for the prediction of T2DM using NN analysis is 0.902, with a sensitivity of 71.4% and a specificity of 93.8%. The network predicts T2DM well with predicted pseudoprobabilities over 0.5. The model's predictive capability (normalized importance) revealed that ACCS is the best model (100%) for the prediction of T2DM, followed by G-CSF (75.5%) and SMAD4 (69.6%). It can be concluded that ACCS, G-CSF, and SMAD4 are important proteins in T2DM prediction, and their increase is associated with the presence of inflammation.

Successful Management of Neutropenic Sepsis Is Key to Better Survival of Patients With Blood Cancer in Sri Lanka: Real-World Data From the Resource-Limited Setting

PURPOSE

Sepsis is the main cause of nonrelapse mortality, and there are no published data on applicability of supportive care protocols from high-income countries such as Sri Lanka. The aim of the study was to investigate management and mortality of neutropenic episodes among Hemato-Oncology patients.

MATERIALS AND METHODS

Retrospective analysis of clinical characteristics, management, morbidity, and mortality of neutropenic Hemato-Oncology patients presented to the Lanka Hospital Blood Cancer Centre from January 1, 2019 to December 31, 2019 was performed.

RESULTS

A total of 169 neutropenic episodes were identified; 115 (68%) of such episodes were related to chemotherapy. Acute leukemia, lymphoproliferative disorders, and plasma cell disorders accounted for 23%, 69%, and 8% of patients, respectively. The median age of patients who had sepsis was 56 years, whereas that of those who had no sepsis was 53 years (P = .49). The median time to neutropenia was 9 days for those in the sepsis group compared with 8 days in the group that had no sepsis (0.64). The median neutrophil count in the group that had sepsis was 0.06, whereas it was 0.69 in the group that had no sepsis (P ≤ .05). The median time to commencement of antibiotics was 20 minutes.

CONCLUSION

To our knowledge, this is the only documented study related to outcome and successful applicability of western supportive care protocols to Sri Lankan patients with neutropenia. In this study, we have shown that neutropenic sepsis can be successfully managed in the setting of limited resources with service development, following guidelines and staff training.

Analytical sameness methodology for the evaluation of structural, physicochemical, and biological characteristics of Armlupeg: A pegfilgrastim biosimilar case study

Pegfilgrastim is administered as an adjunct to chemotherapy to reduce the incidence of febrile neutropenia and associated infectious complications. Lupin's Pegfilgrastim is a proposed biosimilar to the U.S.-referenced Neulasta®. Demonstration of biosimilarity requires extensive physicochemical and functional characterization of the biosimilar, and demonstration of analytical similarity to the reference product, in addition to clinical studies. This work is a case study for demonstrating the analytical similarity of Armlupeg (Lupin's Pegfilgrastim) to Neulasta® with respect to structural and physicochemical attributes using several robust, orthogonal, and state-of-the-art techniques including high-end liquid chromatography, mass spectrometry, and spectroscopy techniques; circular dichroism; differential scanning calorimetry; nuclear magnetic resonance; analytical ultracentrifugation; and micro-flow imaging. Functional similarity was demonstrated using an in vitro cell proliferation assay to measure relative potency and surface plasmon resonance to measure receptor binding kinetics. Furthermore, comparative forced-degradation studies were performed to study the degradation of the products under stress conditions. The product attributes were ranked based on a critical quality attributes risk score according to their potential clinical impact. Based on criticality, all analyses were statistically evaluated to conclude analytical similarity. Lupin's Pegfilgrastim was comparable to Neulasta® as demonstrated via structural, functional, and purity analyses. Lupin's Pegfilgrastim complied with the quality and statistical ranges established using Neulasta®. Both products follow the same degradation pathways under stress conditions as observed in the forced-degradation studies. No new impurity or degradation product was observed in Lupin's Pegfilgrastim. These data conclusively demonstrate the analytical similarity of Lupin's Pegfilgrastim and Neulasta®.

Efficacy and safety of PEG-rhG-CSF versus rhG-CSF in preventing chemotherapy-induced-neutropenia in early-stage breast cancer patients

BACKGROUND

To compare the clinical value of recombinant human granulocyte colony-stimulating factor (rhG-CSF) and pegylated rhG-CSF(PEG-rhG-CSF) in early-stage breast cancer (EBC) patients receiving adjuvant chemotherapy, compare the efficacy of PEG-rhG-CSF with different dose and explore the timing of rhG-CSF rescue treatment.

METHODS

Patients in two PEG-rhG-CSF subgroups were given 3 mg or 6 mg PEG-rhG-CSF within 24 ~ 48 h after chemotherapy for preventing myelosuppression, while patients in the rhG-CSF group were given rhG-CSF. Observation indicators include the incidence of febrile neutropenia (FN) and grade 3/4 chemotherapy-induced-neutropenia (CIN), the overall levels and nadir values of white blood cells (WBC) and absolute neutrophil count (ANC), comparison of WBC and ANC curves over time, the incidence of CIN-related complications, the incidence of adverse events in each group and the timing of rescue treatment for rhG-CSF.

RESULTS

There was no significant difference in the incidence of FN in the first cycle among the groups (P = 0.203). But the incidence of ≥ 3 grade CIN in two PEG-rhG-CSF subgroups was significantly lower than that in the rhG-CSF group (P < 0.001). The overall WBC and ANC levels in the PEG-rhG-CSF group were significantly higher than those in the rhG-CSF group (P < 0.001). In terms of CIN-related complications, less chemotherapy delay rate (1.1 vs. 7.5%, P = 0.092), less dose reduction rate (6.9 vs. 7.5%, P = 1.000), less antibiotic use rate (3.4 vs. 17.5%, P = 0.011) and less proportion of rhG-CSF rescue therapy (24.1 vs. 85.0%, P < 0.001) in the PEG-rhG-CSF group, and there were no significant differences between PEG-rhG-CSF subgroups. In the incidence of adverse events among the groups, there were no statistical differences. All patients undergoing rhG-CSF rescue treatment were mainly 4 grade (63.6%) and 3 grade (25.5%) CIN, and 10.9% of patients with 1 ~ 2 grade CIN who had high infection risk or had been infected.

CONCLUSION

PEG-rhG-CSF has better efficacy and equal tolerance compared with rhG-CSF in preventing CIN in EBC patients receiving EC regimen. Moreover, a half-dose 3 mg PEG-rhG-CSF also had good efficacy. Last, patients with ≥ 3 grade CIN and others who have been assessed to be at high risk of infection or have co-infection should consider rhG-CSF or even antibiotic rescue treatment.

Prescription patterns of granulocyte colony-stimulating factors in patients with breast cancer: A real-world study

BACKGROUND AND OBJECTIVES

Myelosuppressive chemotherapy is effective for breast cancer but carries a potential risk of febrile neutropenia (FN). Clinical practice guidelines have recommended prophylaxis with granulocyte colony-stimulating factor (G-CSF) to reduce the incidence of FN in patients receiving chemotherapy. We aimed to examine the use of G-CSFs for primary prophylaxis for FN and to see whether it follows the guidelines. In addition, we examined the changes in the use of long-acting and short-acting G-CSFs in patients with breast cancer over the past ten years.

METHODS

This was a retrospective observational real-world study. The data were obtained from the clinical research database of three hospitals affiliated with Taipei Medical University. Patients with breast cancer who initiated their first chemotherapy regimen between January 1, 2011, and December 31, 2020, were identified by the ICD codes and their use of filgrastim or pegfilgrastim was identified by the Anatomical Therapeutic Chemical codes. Whether and how G-CSF was prescribed during the study patients' first chemotherapy regimen was examined, and the annual change in the total number of short- and long-acting G-CSFs prescribed to the study patients from 2011 to 2020 was analyzed.

RESULTS

Among the 2,444 patients who were prescribed at least one of the examined 15 breast cancer chemotherapy drugs, 1,414 did not use any G-CSFs during their first chemotherapy regimen while 145 used G-CSFs for primary prophylaxis and 185 for treatment. Among the patients receiving high FN risk regimens, only 8.6% used G-CSF for primary prophylaxis. The average (± SD) number of days for short-acting G-CSF use was 2.3 (± 1.5) days with a median of 2 days. In addition, it was found that there was a significant reduction in long-acting G-CSF use (p = 0.03) whereas the changes in short-acting G-CSF use over time were not significant (p = 0.50).

CONCLUSIONS

Our study results show that G-CSFs are used for primary prophylaxis in a small percentage of patients with breast cancer and the duration of short-acting G-CSF use is relatively short. Considering the significant clinical and economic impact of FN, it is hoped that the prescription patterns of G-CSFs observed can provide an important reference for future clinical practice and reimbursement policy.

Two decades of pegfilgrastim: what have we learned? Where do we go from here?

Chemotherapy-induced febrile neutropenia (FN) is a medical emergency that may occur in patients with malignancies receiving myelosuppressive chemotherapy. FN requires early therapeutic intervention since it is associated with increased hospitalizations and high mortality risk of 5%-20%. FN-related hospitalizations are higher in patients with myeloid malignancies than in those with solid tumors due to the myelotoxicity of chemotherapy regimens and the compromised bone marrow function. FN increases the burden of cancer by causing chemotherapy dose reductions and delays. The administration of the first granulocyte colony-stimulating factor (G-CSF), filgrastim, reduced the incidence and duration of FN in patients undergoing chemotherapy. Filgrastim later evolved into pegfilgrastim, which has a longer half-life than filgrastim and was associated with a lower rate of severe neutropenia, chemotherapy dose reduction, and treatment delay. Nine million patients have received pegfilgrastim since its approval in early 2002. The pegfilgrastim on-body injector (OBI) is an innovative device facilitating the time-released auto-injection of pegfilgrastim approximately 27 hours after chemotherapy, as clinically recommended for the prevention of FN, thus eliminating the need for a next-day hospital visit. Since its introduction in 2015, one million patients with cancer have received pegfilgrastim using the OBI. Subsequently, the device has been approved in the United States (US), European Union, Latin America, and Japan, with studies and a postmarketing commitment demonstrating device reliability. A recent prospective observational study conducted in the US demonstrated that the OBI substantially improved the adherence to and compliance with clinically recommended pegfilgrastim therapy; patients receiving pegfilgrastim via the OBI experienced a lower incidence of FN than those receiving alternatives for FN prophylaxis. This review discusses the evolution of G-CSFs leading to the development of the OBI, current recommendations for G-CSF prophylaxis in the clinic, continued evidence supporting next-day pegfilgrastim administration, and improvements in patient care made possible with the OBI.

The reliability of FEbrile Neutropenia after ChEmotherapy (FENCE) scores in predicting granulocyte colony-stimulating factor breakthrough febrile neutropenia among patients with lymphoma undergoing first-cycle chemotherapy: A prospective observational study

Background

A tool for estimating risk of febrile neutropenia (FN) after chemotherapy, namely the FEbrile Neutropenia after ChEmotherapy (FENCE) score, has been developed but has not been widely validated. This study aimed to validate the FENCE score as a tool for predicting granulocyte colony-stimulating factor (G-CSF) breakthrough FN among patients with lymphoma who underwent chemotherapy.

Methods

This was a prospective observational study of treatment-naive adult patients with lymphoma who underwent their first cycle of chemotherapy between 2020 and 2021. The patients were followed up until the next cycle of chemotherapy to identify any infection events.

Results

Among the 135 patients with lymphoma, 62 (50%) were men. In a comparison of the value of each FENCE parameter for predicting G-CSF breakthrough infection, the parameter of advanced-stage disease showed high sensitivity of 92.8%, and receipt of platinum chemotherapy showed high specificity of 95.33%. With a FENCE score of 12 as a cutoff for low risk, analysis across all patients with lymphoma resulted in a high AUROCC of 0.63 (95% CI = 0.5–0.74%; p = 0.059), and analysis across only patients with diffuse large B-cell lymphoma (DLBCL) resulted in an AUROCC of 0.65 (95% CI = 0.51–0.79%; p = 0.046). With a cutoff point of 12, FENCE score can predict breakthrough infection events at 30.0% (95% CI = 17.8–47.4%).

Conclusion

This study divided patients with lymphoma into risk groups according to FENCE score, showing that this instrument has discriminatory ability in predicting FN events, these being more likely to occur in patients in the intermediate- and high-risk groups. Multicenter studies are needed to validate this clinical risk score.

Outcome and Cost-Effectiveness Analysis of Long-acting G-CSF as Primary Prophylaxis of Neutropenia Induced by Chemotherapy in Breast Cancer Patients, From a Retrospective Study

PURPOSE

This retrospective analysis aimed to evaluate the clinical outcomes and cost-effectiveness of long-acting granulocyte-colony stimulating factor as primary prophylaxis of neutropenia caused by chemotherapy for breast cancer.

METHODS

Patients with breast cancer who received long- or short-acting granulocyte-colony stimulating factor as primary prophylaxis of neutropenia were enrolled in this study, and incidences of neutropenia were compared between two groups. A decision-analytic and a Markov model were used to compare the health benefits and costs of utilizing long- vs short-acting granulocyte-colony stimulating factor as the primary prophylaxis from the perspective of the Chinese health service system. Subsequently, one-way deterministic and probabilistic sensitivity analyses were conducted. The incremental cost-effectiveness ratios were calculated in baseline and sensitivity analyses.

RESULTS

Patients receiving long-acting granulocyte-colony stimulating factor as the primary prophylaxis of chemotherapy-induced neutropenia experienced a significant lower incidence of this adverse event, compared with the short-acting one for 2 to 7 days. The outcomes of baseline analysis indicated that long-acting granulocyte-colony stimulating factor had a gain of 0.08 quality-adjusted life years and costed $149 more than the short-acting one, yielding an incremental cost-effectiveness ratio of $1792 per quality-adjusted life year. The sensitivity analysis proved the stability of our models and economic efficiency of long-acting granulocyte-colony stimulating factor.

CONCLUSIONS

Patients receiving long-acting granulocyte-colony stimulating factor as primary prophylaxis of neutropenia experienced lower risk of this event compared with those underusing short-acting one. The long-acting granulocyte-colony stimulating factor may be a more cost-effective strategy for primary prophylaxis of neutropenia than short-acting one, considering the Chinese willingness-to-pay threshold of $12158.6 per quality-adjusted life year.

[G-CSF for prophylaxis of neutropenia and febrile neutropenia, anemia in cancer : Guidelines on supportive treatment part 1]

Infections in patients with neutropenia following chemotherapy are mostly manifested as fever (febrile neutropenia, FN). Some of the most important determinants of the risk of FN are the type of chemotherapy, the dose intensity and patient-specific factors. When the risk of FN is 20% or more granulopoiesis is prophylactically stimulated with granulocyte colony stimulating factor (G-CSF) after the treatment. Anemia should always be clarified and if necessary be treated according to the cause when symptomatic. If an absolute or functional iron deficiency is present, intravenous iron substitution is mostly necessary. Erythropoiesis-stimulating agents can be used after chemotherapy with hemoglobin (Hb) levels less than 10 g/dl (6.2 mmol/l). In cases of chronic anemia and Hb levels less than 7-8 g/dl (<4.3-5.0 mmol/l) the indications for transfusion of erythrocyte concentrates should be assessed primarily based on the individual clinical symptoms.

Prospective external validation of an updated algorithm to quantify risk of febrile neutropenia in cancer patients after a cycle of chemotherapy

PURPOSE

Febrile neutropenia resulting from chemotherapy is a significant cause of morbidity and mortality in cancer patients. We had previously published the associates of the risk of febrile neutropenia, and this study now extends and modifies the previous model as well as tests its external validity.

METHODS

We have recruited documented febrile neutropenia cases with solid tumors, in addition to a selected control group of cancer patients from one institution treated between 2015 and 2019. We then united our sample with our previously published original derivation group, to modify and update our previous model by logistic regression analysis. Additionally, consecutive cancer patients from 5 institutions were recruited in 2020 to test external validity of the resultant algorithm.

RESULTS

A total of 4075 cycles of chemotherapy in 1282 cases were recruited in the updated, new model derivation group, and a total of 8 variables were selected for the updated algorithm. In the new external validation group, 653 cycles of chemotherapy in 624 patients were analyzed, to indicate that after cycles without prophylactic granulocyte colony-stimulating factor (GCSF) usage, the algorithm yielded a sensitivity value of 91%, specificity of 40%, and an area under curve (AUC) figure of 0.78, when a risk cutoff threshold value of ≥ 0.20 is chosen. This algorithm is now embedded in a web application for free clinical use.

CONCLUSION

Our algorithm identifies and quantifies the risk of febrile neutropenia in cancer patients. Further studies are required to improve this model with additional predictors.

Febrile neutropenia prophylaxis, G-CSF physician preferences: discrete-choice experiment

OBJECTIVES

Febrile neutropenia (FN) commonly occurs during cancer chemotherapy. Prophylaxis with granulocyte colony-stimulating factors (G-CSFs) is known to reduce the severity and incidence of FN and infections in patients with cancer. Despite the proven efficacy, G-CSFs are not always prescribed as recommended. We performed a discrete-choice experiment (DCE) to determine what factors drive the physician preference for FN prophylaxis in patients with cancer undergoing chemotherapy.

METHODS

Attributes for the DCE were selected based on literature search and on expert focus group discussions and comprised pain at the injection site, presence of bone pain, associated fever/influenza syndrome, efficacy of prophylaxis, biosimilar availability, number of injections per chemotherapy cycle and cost. Oncologists, in a national database, were solicited to participate in an online DCE. The study collected the responses to the choice scenarios, the oncologist characteristics and their usual prescriptions of G-CSFs in the context of breast, lungs and gastrointestinal cancers.

RESULTS

Overall, the responses from 205 physicians were analysed. The physicians were mainly male (61%), with ≤20 years of experience (76%) and working only in public hospitals (73%). The physicians prescribe G-CSF primary prophylaxis for 32% of patients: filgrastim in 46% and pegfilgrastim in 54%. The choice of G-CSF for primary and secondary prophylaxis was driven by cost and number of injections. Biosimilars were well accepted.

CONCLUSION

Cost and convenience of G-CSF drive the physician decision to prescribe or not G-CSF for primary and secondary FN prophylaxes. It is important that these results be incorporated in the optimisation of G-CSF prescription in the clinical setting.

Blood cancer care in a resource limited setting during the Covid-19 outbreak; a single center experience from Sri Lanka

BACKGROUND

The Covid-19 pandemic has caused significant morbidity and mortality among patients with cancer. Most countries employed measures to prevent spread of Covid-19 infection which include shielding, quarantine, lockdown, travel restrictions, physical distancing and the use of personal protective equipment. This study was carried out to assess the change in patient attendance and the efficacy of newly implemented strategies to mitigate the impact of Covid-19 on services at the Lanka Hospital Blood Cancer Centre (LHBCC) in Colombo, Sri Lanka.

METHODOLOGY

Telephone consultation, infection control, personal protective measures and emergency admission policy were implemented with the aim of having a Covid-19 free ward and to prevent cross-infections. This descriptive cross-sectional study was conducted with 1399 patient episodes (in-patient care or day-case review). We analysed patients treated as in-patient as well as day-case basis between 01st April 2020 and 31st December 2020.

RESULTS

There were 977 day-case based episodes and 422 in-patient based episodes. There was a 14% drop in episode numbers compared to same period in 2019. There was no cross infection and no patients with Covid-19 related symptoms or positive test results entered the LHBCC during the study period.

CONCLUSION

Services in blood cancer care were maintained to prevent late stage presentation and adverse outcome. Measures implemented to prevent Covid-19 were effective to allow continuation of treatment. This study highlights the importance of implementing strict protocols, clinical screening, use of appropriate personal protective equipment in delivering blood cancer care during the Covid-19 pandemic. This is the only documented study relating to outcome and successful applicability of measures to prevent spread of Covid-19 infection and maintaining services among blood cancer patients in Sri Lanka.

Granulocyte Colony Stimulating Factor Expression in Breast Cancer and Its Association with Carbonic Anhydrase IX and Immune Checkpoints

Simple Summary

Preclinical studies suggest that interactions between granulocyte colony-stimulating factor (G-CSF) and hypoxia-induced carbonic anhydrase IX regulate the trafficking and function of immune cells in the tumour microenvironment. We investigated the clinical significance of this crosstalk by analyzing the protein expression of G-CSF and macrophage markers by immunohistochemistry on a well-characterized tissue microarray series of invasive breast cancers. We report that high expression of G-CSF on breast carcinoma cells is linked with significantly improved survival in an important group of breast cancers that do not respond to hormonal therapy. These tumours were infiltrated by immune cells expressing biomarkers that can be targeted with immune checkpoint inhibitor drugs. In contrast, carbonic anhydrase IX expression was associated with unfavourable outcomes.

Abstract

Purpose: Granulocyte colony-stimulating factor (G-CSF) and hypoxia modulate the tumour immune microenvironment. In model systems, hypoxia-induced carbonic anhydrase IX (CAIX) has been associated with G-CSF and immune responses, including M2 polarization of macrophages. We investigated whether these associations exist in human breast cancer specimens, their relation to breast cancer subtypes, and clinical outcome. Methods: Using validated protocols and prespecified scoring methodology, G-CSF expression on carcinoma cells and CD163 expression on tumour-associated macrophages were assayed by immunohistochemistry and applied to a tissue microarray series of 2960 primary excision specimens linked to clinicopathologic, biomarker, and outcome data. Results: G-CSF_high expression showed a significant positive association with ER negativity, HER2 positivity, presence of CD163+ M2 macrophages, and CAIX expression. In univariate analysis, G-CSF_high phenotype was associated with improved survival in non-luminal cases, although the CAIX+ subset had a significantly adverse prognosis. A significant positive association was observed between immune checkpoint biomarkers on tumour-infiltrating lymphocytes and both G-CSF- and CAIX-expressing carcinoma cells. Immune checkpoint biomarkers correlated significantly with favourable prognosis in G-CSF_high/non-luminal cases independent of standard clinicopathological features. Conclusions: The prognostic associations linking G-CSF to immune biomarkers and CAIX strongly support their immunomodulatory roles in the tumour microenvironment.