Impact of neutropenia on delivering planned adjuvant chemotherapy: UK audit of primary breast cancer patients

The UK audit was undertaken in primary breast cancer patients receiving adjuvant chemotherapy to: (1) record the incidence of neutropenic events (hospitalisation due to febrile neutropenia, dose delay of > or =1 week or dose reduction of > or =15% due to neutropenia); (2) evaluate the impact of neutropenic events on overall dose intensity (DI) received and (3) review the use of granulocyte colony-stimulating factor (G-CSF) in clinical practice. Data from 422 patients with Stage I-III breast cancer were collected from 15 centres. Cyclophosphamide, methotrexate and 5-fluorouracil(CMF)- or anthracycline-based regimens were the most commonly used. Only 5.2% of patients received G-CSF. Overall, 29% of patients experienced a neutropenic event, most frequently dose delay. Neutropenic events had a significant impact on the ability to deliver planned DI. Out of 422 patients, 17% did not achieve 85% of their planned DI; due to neutropenia in 11% of patients. Of the neutropenic patients receiving CMF- or anthracycline-based regimens, around 40 and 32% of patients, respectively, did not achieve 85% of their planned DI. Patients who experienced one neutropenic event had a higher risk of a second event. During adjuvant chemotherapy of primary breast cancer, neutropenic events are common, likely to occur in subsequent chemotherapy cycles, and have a significant impact on receiving planned DI.