Purpose: To analyze the safety and efficacy of a short course of granulocyte colony-stimulating factor (G-CSF) to maintain dose-intensity of subsequent cycles of chemotherapy after a prior episode of prolonged neutropenia, without febrile complications, in patients receiving adjuvant treatment for breast cancer.
Patients and methods: Thirty-two patients undergoing adjuvant cyclophosphamide, methotrexate, and fluorouracil (CMF) or doxorubicin-CMF for stages I to II breast cancer were included after having chemotherapy delays due to neutropenia (absolute neutrophil count [ANC] < 1.5 x 10(9)/L) on day 22. G-CSF was administered subcutaneously on days 15 to 19 of each subsequent cycle.
Results: None of the patients included in this study had to be admitted to the hospital for fever and neutropenia. The median percentage of the projected dose-intensity for CMF or doxorubicin-CMF on an intent-to-treat basis was 0.994, which was significantly higher than the delivered dose-intensity before the start of G-CSF treatment (P < .0001). Patients who received concomitant G-CSF and radiotherapy achieved a similar dose-intensity as patients who did not undergo radiotherapy. Seven patients discontinued G-CSF treatment due to musculoskeletal pain. These patients had more subsequent cycle delays because of day 22 neutropenia than the 25 patients who followed the G-CSF schedule (P = .0028).
Conclusion: A 5-day course of G-CSF in patients with prior chemotherapy delays due to prolonged neutropenia seems to be a safe and cost-effective schedule to maintain CMF or doxorubicin-CMF dose-intensity in the adjuvant treatment of breast cancer.