Colony-stimulating factor prescribing patterns in patients receiving chemotherapy for cancer

To examine variables influencing colony-stimulating factor (CSF) prescription as primary prophylaxis versus other use during patients' initial chemotherapy course among a large sample of health insurance records.

Retrospective cohort study.

Adults 25 years or older with a diagnosis of breast, colorectal, or non-small cell lung cancer (NSCLC) between January 1, 2002, and December 31, 2005, were identified from the western Washington State Surveillance, Epidemiology, and End Results Seattle Puget Sound registry. We linked these records to health insurance claims. Chemotherapy regimens identified from insurance claims were categorized as carrying high, intermediate, or low risk of myelosuppression according to the National Comprehensive Cancer Network guidelines and the literature. Colony-stimulating factor use was described as primary prophylaxis, other use, or no use, and logistic regression analysis identified factors associated with CSF use.

For patients with breast cancer, colorectal cancer, and NSCLC, respectively, 58%, 0%, and 28% received CSFs as primary prophylaxis in conjunction with high-risk chemotherapy regimens, whereas 10%, 7%, and 21% did so in conjunction with low-risk chemotherapy regimens. Prophylactic CSF use increased from 2002 to 2005 for breast cancer but remained constant for colorectal cancer and for NSCLC.

As primary prophylaxis, CSF use is underutilized based on recommendations for patients having cancer who receive chemotherapy regimens carrying high febrile neutropenia risk and may be overutilized for patients who receive chemotherapy regimens carrying low febrile neutropenia risk. Further research is needed to understand the barriers to implementing guidelines in clinical practice.