Febrile neutropenia (FN) is defined as an elevated axillary temperature >38.5 °C, held for more than 1 hour, along with an absolute neutrophil count (ANC) <0.5 × 10^9/L. Let's learn about the application of granulocyte colony-stimulating growth factor (G-CSF) and hematopoietic growth factors (hGFs) in the ESMO guidelines. The incidence of FN and mortality rates Except for acute leukemia, the incidence of reduced neutrophil count during standard-dose chemotherapy for malignancies is high, while the incidence of FN (10%-57%) and mortality (0-7%) are relatively low. the incidence of FN in WHO grade 4 leukopenia and WHO grade 3/4 infection is 2%-28% and 16%, respectively. Prevention of FN with hGFs Patients who are not at high risk of developing FN or neutropenia-related complications do not require granulocyte colony-stimulating growth factor (G-CSF), and the use of hGFs for FN is not recommended, except for high-risk such as sepsis, tissue infections, and prolonged granulocytopenia. Patients with fever not caused by neutropenia, such as community or hospital-acquired pneumonia, are not suitable for the above treatment. Special conditions for treatment with hGFs criteria Primary prevention: reduction of bone marrow hematopoietic stores >20% due to radiotherapy (see Table 1), HIV, age ≥ 65 years using curative chemotherapy regimens, dose reduction unfavorable for treatment outcome. Secondary prevention: continued treatment of recurrent and potentially life-threatening infections; doses below minimum use requirements; delayed chemotherapy; decreased adherence due to decreased cure rates and survival. Treatment of high-risk FN: prolonged (more than 7 days) FN, hypotension, sepsis, pneumonia, or fungal infection. Table 1 Chemotherapy regimens leading to a 20% risk of FN Use of G-CSF for FN prophylaxis G-CSF 5 μg/Kg/d subcutaneously (s.c.) starting 24-72 hours after the end of chemotherapy until ANC recovers and stabilizes (but need not exceed 10×10^9/L). A single pegfilgrastim s.c. injection at 100 μg/Kg (individualized) or a total of 6 mg (generic regimen), both being equivalent. 1. Indications Controversial: autologous PBSC TPL, ALL Use of G-CSF: autologous myelosuppression, allogeneic bone marrow transplantation, graft failure, 3-10 Gy potentially fatal radiation injury due to bone marrow failure No use of G-CSF: AML, MDS, <3 Gy sustained survival with proper care and >10 Gy fatal radiation injury due to damage to other organs (e.g., gastrointestinal tract), During radiotherapy treatment of chest and female breast cancer (what are the reasons? Focus on tumor time, reply to the password 1202 to get the answer) and myelodysplastic syndrome (MDS) have an increased risk of development, although the absolute risk is low but the benefit outweighs the risk). 2. The use of G-CSF and pegfilgrastim in high-risk conditions for the treatment of acute leukemia with autologous and allogeneic stem cell transplants (TPLs) results in an increased risk of FN and can have potentially lethal complications. Incidence of FN in high-risk situations: FN can occur routinely with autologous and allogeneic peripheral blood stem cell (PBSC) TPLs and bone marrow TPLs, as well as with graft failure; 35% to 48% with AML diagnosis and 13% to 30% with acute lymphoblastic leukemia (ALL) induction chemotherapy. Mortality: 0 to 10% with autologous TPLs; highly variable with allogeneic TPLs; 80% with graft 80% in case of failure; 20% to 26% in the 2 months before diagnosis of AML; 2% to 10% in ALL induction chemotherapy. 3.G-CSF after autologous stem cell TPL Bone marrow TPL: the use of hGF can be delayed until day 5-7, and the recommended dose of G-CSF is 5 μg/Kg/d. PBSC TPL: it can restore ANC for a short time, but it cannot be translated into clinical benefit, and it is not recommended for the standard-risk patients. 4. The use of G-CSF after allogeneic TPL The application of G-CSF after bone marrow TPL is reasonable, but only the recovery of ANC has clinical benefit, and treatment is started on the 5th to 7th day after TPL. PBSCs Mobilization 1. autologous PBSC hGFs ± chemotherapy effective, recommended dose G-CSF 10 μg/Kg/d for 7-10 days prior to collection. hGF Mobilization PBSCs are superior to hGFs after bone marrow stem cell co-infusion in terms of ANC recovery. 2. allogeneic PBSC whose advantages are convenience, rapid ANC recovery, no increase in acute graft-versus-host disease, post-PBSC The rapid ANC recovery is comparable to that of bone marrow stem cells. The recommended dose of G-CSF 10 μg/Kg/d is continued for 7-10 days before collection, and chemotherapy can be added.