Febrile neutropenia in adjuvant docetaxel and cyclophosphamide (TC) with prophylactic pegfilgrastim in breast cancer patients: a retrospective analysis

US Oncology Research Trial 9735 reported that TC improved overall survival when compared to doxorubicin and cyclophosphamide in early-stage breast cancer. Despite 61% grades 3–4 neutropenia in the TC arm, only 5% of patients developed febrile neutropenia (FN) without primary prophylactic GCSF (ppGCSF). TC has risen in popularity, particularly in older patients or in those where an anthracycline is contraindicated. Other studies examining the toxicity of TC without ppGCSF reported a higher incidence of FN between 23 and 46%. We reviewed our institutional experience with ppGCSF and the TC regimen. Women treated with adjuvant TC and pegfilgrastim at Roswell Park Cancer Institute were identified from the pharmacy database between 8/2006 and 11/2010. Patient characteristics and comorbidities were abstracted. Endpoints included incidence of FN, hematologic toxicities, relative dose intensity (RDI), and other acute complications. Docetaxel 75 mg/m² and cyclophosphamide 600 mg/m² were given every 21 day/cycle for a planned four cycles. All patients received pegfilgrastim 6 mg on day 3. One hundred and eleven women with median age of 56 years (27–79) were identified. Twenty-two percent of patients were ≥65 at diagnosis. Eight patients developed FN (7%). Ninety-five patients (86%) were able to complete four cycles. Completion rate was significantly lower in patients with age ≥65 (71% vs. 90%; P = 0.02). Incidence of hospitalization, delay, RDI <85%, and dose reduction were not significantly different between the age groups. The overall incidence of FN was 7%. Older patients were significantly less likely to complete four cycles of TC as planned. ppGCSF should be strongly considered in breast cancer patients receiving adjuvant TC chemotherapy.