Use of granulocyte colony stimulating factor (GCSF) in patients receiving highly myelosuppressive chemotherapy for breast cancer.

Abstract

e21677 Background:We hypothesized that GCSF use may be suboptimal in the real world despite prior research that shows prophylaxis with GCSF can reduce neutropenic fevers and hospitalizations. Our aims were to characterize patterns of GCSF use in a population-based cohort of breast cancer patients receiving highly myelosuppressive chemotherapy and to describe outcomes and predictors associated with appropriate GCSF prophylaxis. Methods:Patients diagnosed with breast cancer from 2008 to 2012, seen at any 1 of 5 comprehensive cancer centers in a Canadian province, and treated with chemotherapy that posed > 20% risk of neutropenic fever were reviewed. Associations between GCSF use and 1) patient and physician factors and 2) treatment outcomes, including rate of neutropenic fevers, were analyzed using regression models. Results:We included 805 women: median age was 52 (IQR 44 to 61) years, 40% reported smoking, 52% used alcohol regularly, 64% were ECOG 0, and 24% had private health insurance. In this cohort, 330 (41%) patients were given GCSF. Among those treated with GCSF, 132 (40%) and 198 (60%) individuals received GCSF as primary and secondary prophylaxis, respectively. Overall, neutropenia was noted in 467 (58%) cases while neutropenic fever was experienced by 161 (20%) patients. When compared to those who did not use GCSF, patients who used GCSF experienced a lower rate of neutropenia (14% vs. 61%, p < 0.01) and a decreased incidence of neutropenic fever (8% vs. 23%, p < 0.01). In regression models, patients lacking extended medical coverage (32% vs. 49%, p = 0.02), poor performance status (30% vs. 55%, p = 0.03), and those who were evaluated at non-teaching institutions (25% vs. 69% p < 0.01) were less likely to receive GCSF. Patients seen at non-teaching institutions were also given primary GCSF prophylaxis less frequently (16% vs 59%, p < 0.01) than those at teaching centers. Conclusions:GCSF prophylaxis was associated with improved neutropenia-related outcomes in the real world. Despite evidence-based recommendations, use of GCSF remains suboptimal in this population-based cohort of breast cancer patients receiving highly myelosuppressive chemotherapy.