Uptake and economic impact of first-cycle colony-stimulating factor use during adjuvant treatment of breast cancer

Abstract

Purpose: In 2002, pegfilgrastim was approved by the US Food and Drug Administration and the benefits of dose-dense breast cancer chemotherapy, especially for hormone receptor (HR) -negative tumors, were reported. We examined first-cycle colony-stimulating factor use (FC-CSF) before and after 2002 and estimated US expenditures for dose-dense chemotherapy.

Methods: We identified patients in Surveillance, Epidemiology, and End Results-Medicare greater than 65 years old with stages I to III breast cancer who had greater than one chemotherapy claim within 6 months of diagnosis(1998 to 2005) and classified patients with an average cycle length less than 21 days as having received dose-dense chemotherapy. The associations of patient, tumor, and physician-related factors with the receipt of any colony-stimulating factor (CSF) and FC-CSF use were analyzed by using generalized estimating equations. CSF costs were estimated for patients who were undergoing dose-dense chemotherapy.

Results: Among the 10,773 patients identified, 5,266 patients (48.9%) had a CSF claim. CSF use was stable between 1998 and 2002 and increased from 36.8% to 73.7% between 2002 and 2005, FC-CSF use increased from 13.2% to 67.9%, and pegfilgrastim use increased from 4.1% to 83.6%. In a multivariable analysis, CSF use was associated with age and chemotherapy type and negatively associated with black/Hispanic race, rural residence, and shorter chemotherapy duration. FC-CSF use was associated with high socioeconomic status but not with age or race/ethnicity. The US annual CSF expenditure for women with HR-positive tumors treated with dose-dense chemotherapy is estimated to be $38.8 million.

Conclusion: A rapid increase in FC-CSF use occurred over a short period of time, which was likely a result of the reported benefits of dose-dense chemotherapy and the ease of pegfilgrastim administration. Because of the increasing evidence that elderly HR-positive patients do not benefit from dose-dense chemotherapy, limiting pegfilgrastim use would combat the increasing costs of cancer care.

Fig 1.

Adjuvant colony-stimulating factor (CSF) use over time: (A) CSF at any time during adjuvant chemotherapy; (B) CSF with first cycle of adjuvant chemotherapy; and (C) CSF with first cycle of combination anthracycline and taxane chemotherapy.

Fig 2.

Increase in use of pegfilgrastim after US Food and Drug Administration approval. CSF, colony-stimulating factor.

Fig 3.

Change in adjuvant chemotherapy regimens over time in elderly women with breast cancer.

Fig 4.

Febrile neutropenia rates over time with colony-stimulating factor (CSF) use at any time during adjuvant chemotherapy, with the first cycle of any adjuvant chemotherapy, with the first cycle of combination anthracycline and taxane chemotherapy, and without CSF.