BACKGROUND: The aim of this study is to identify factors that increase the occurrence of severe neutropenia (SN) and febrile neutropenia (FN) during docetaxel treatment for castration-resistant prostate cancer (CRPC).
METHODS: We retrospectively reviewed 258 courses during the first three cycles among 95 patients. Docetaxel at a dose of 75 mg/m2 was administered every 3 or 4 weeks. Patient background, laboratory data, and bone scan results were collected to assess predictive factors for SN and FN. We defined SN as an absolute neutrophil count (ANC) of < 500/mm3 and defined FN as an ANC of < 1000/mm3 with a body temperature of >38.3 °C.
RESULTS: The mean age of the patients was 72.6 ± 6.4 years and the mean prostate-specific antigen was 135.4 ± 290.9 ng/ml. During the first three courses of treatment, SN occurred in 72.6 % of patients and FN occurred in 9.5 % of patients. Univariate analysis demonstrated that age ≥75 years (p = 0.002), number of comorbidities ≥1.2 (p = 0.008 and p = 0.006) and previous external beam radiation therapy (EBRT) (p = 0.001) were predictive factors for the development of SN or FN. In multivariate analysis, significant predictors of SN or FN were age ≥75 years (hazard ratio [HR] 5.77; p = 0.004) and previous EBRT (HR 14.5; p = 0.012). According to the subgroup analysis dividing SN and FN separately, multivariate analysis also revealed that age ≥75 years and previous EBRT were also significant predictors for developing SN (HR 5.09; p = 0.023, HR 12.7; p = 0.020, respectively) and for developing FN (HR 5.45; p = 0.042, HR 7.72; p = 0.015, respectively).
CONCLUSIONS: Patients aged ≥75 years and with a history of localized radiation therapy are at higher risk for significant neutropenic events and require closer surveillance.
Shigeta K, Kosaka T, Yazawa S, Yasumizu Y, Mizuno R, Nagata H, Shinoda K, Morita S, Miyajima A, Kikuchi E, Nakagawa K, Hasegawa S, Oya M. Are you the author?
Department of Urology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan.
Reference: Int J Clin Oncol. 2014 Sep 9. Epub ahead of print.