Suboptimal Duration of Granulocyte Colony–stimulating Factor Use and Chemotherapy-induced Neutropenia in Women Diagnosed With Breast Cancer

Abstract

PurposeProphylactic use of granulocyte colony–stimulating factor (G-CSF) is recommended for cancer patients who are at high risk of neutropenic events. However, whether the clinical effectiveness of G-CSF from randomized controlled trials translates into “real-world” clinical practice is questionable. The goal of this retrospective cohort study was to examine the impact of G-CSF prophylaxis and other potential risk factors of severe neutropenia in women with breast cancer. MethodsOur study subjects were women who were diagnosed with breast cancer and who received a new course of chemotherapy between January 1, 2010, and December 31, 2010, at a cancer center in Taiwan. Generalized estimating equations were applied to examine the association between G-CSF prophylaxis and neutropenic events. FindingsWe identified 353 women with breast cancer who received a total of 2776 cycles of chemotherapy. G-CSF was used as primary prophylaxis in 7% (n = 202) of cycles and as secondary prophylaxis in 11% (n = 319) of cycles. The mean duration of G-CSF for primary and secondary prophylaxis was 4.9 and 3.7 days, respectively. A chemotherapy regimen with high risk of febrile neutropenia was found to be a risk factor for severe neutropenic events (odds ratio, 3.22 [95% CI, 1.97–5.27]). Prophylactic use of G-CSF was not statistically significantly associated with febrile neutropenia. ImplicationsThe major determinants of neutropenic events among patients with breast cancer were the content and intensity of chemotherapy regimens. Suboptimal use of G-CSF may not be effective in preventing neutropenic events among women with breast cancer.