Granulocyte colony-stimulating factor (G-CSF) patterns of use in cancer patients receiving myelosuppressive chemotherapy

Febrile neutropenia (FN) is a common and serious complication of myelosuppressive chemotherapy. Guidelines recommend primary granulocyte colony-stimulating factors (G-CSF) prophylaxis (PPG) in patients with a high risk (HR, > 20 %) of developing FN. We performed a retrospective analysis using a subset of the Medicare 5 % database to assess patterns of G-CSF use and FN occurrence among elderly cancer patients receiving myelosuppressive chemotherapy. Chemotherapy courses for patients aged 65+ years were identified; only the first course was used for this analysis. Using clinical guidelines, chemotherapy regimens were classified as HR or intermediate risk (IR) for FN. The first administration of G-CSF was classified as either PPG (within the first 5 days of the first cycle), secondary prophylaxis, or reactive. Twelve thousand seven hundred seven courses across five tumor types were classified as having a HR or IR regimen. G-CSF was used in 24.5-73.8 % of patients receiving a HR FN regimen, with the highest use in breast cancer or NHL. Except for breast cancer (where PPG was used in 52.1 %), PPG was given in less than half of patients receiving a HR regimen. Depending on the tumor type, 4.8-22.6 % of patients with a HR regimen had a neutropenia-related hospitalization. Guidelines recommend PPG with HR FN regimens and older age (> 65 years), an important risk factor for developing severe neutropenic complications. However, our results show that in this elderly population, PPG was not routinely used (range 4.8-52.1 %) in patients receiving HR FN regimens. Careful attention to FN risk factors, including chemotherapy regimen and patient age, is needed when planning treatment strategies.