The clinical efficacy of pegfilgrastim to prevent febrile neutropenia in breast cancer patients receiving docetaxel- cyclophosphamide chemotherapy

Abstract Background and aim : For early-stage breast cancer patients, the myelosuppressive chemotherapy such as docetaxel and cyclophosphamide (TC) chemotherapy are frequently introduced as an adjuvant treatment postoperatively. This regimen is known to develop febrile neutropenia (FN) commonly, therefore a newly developed granulocyte colony-stimulating factor (G-CSF), pegfilgrastim, play an important role in preventing the occurrence of FN. In this study, the clinical advantage of pegfilgrastim during the TC chemotherapy was evaluated by the comparison with the conventional filgrastim. Patients and method : A total of 85 patients with stage I or II breast cancer who received TC chemotherapy were divided into the 2 groups, which included: the one that consisted of the patients experienced prophylactic pegfilgrastim administration (named as PEG(+)); the two that consisted of the patients received chemotherapy only with contemporary G-CSF agent, filgrastim that was administered when they suffered from FN or severe neutropenia (named as PEG(-)). This study method was drawn up to evaluate the effectiveness of pegfilgrastim for the prevention of FN and keeping the high relative dose intensity (RDI) (1st endpoint) and to explore whether pegfilgrastim usage might affect the disease-free survival of the patients (2nd endpoint). Results The number of the patients that were diagnosed as Grade 3 to 4 “neutrophil count discount” according to common terminology criteria for adverse events version 5.0 was 21 and 6 in PEG(-) and PEG(+), respectively (P = 0.0238). The odds ratio for the onset of “neutrophil count decreased” ranging with Grade 3 to 4 of PEG(+) compared to that of PEG(-) was 0.1143 (95% confidence interval, 0.0175–0.7446). The significant difference of disease-free survival rates of each could not reach the significant level, because the number of events were small. Conclusion The administration of pegfilgrastim significantly reduced the risk of development of FN with acceptable adverse events. The chemotherapy RDI of the patients who had prophylactic use of pegfilgrastim was significantly higher than that of the patients who were administered conventional filgrastim by physician’s decision. In this study, we could verify the clinical effectiveness of pegfilgrastim on the patients receiving TC chemotherapy.