Platelet count and dose, but not comorbidities, predict severe neutropenia in cabazitaxel-treated prostate cancer patients: A retrospective observational study.

Objective: To determine the safety of cabazitaxel and predictors of severe neutropenia caused by cabazitaxel in a patient population that includes those with comorbidities.

Materials and methods: Of 42 prostate cancer patients treated with cabazitaxel at Osaka Medical and Pharmaceutical University Hospital between September 2014 and June 2022, 33 were included in this study, whereas 6 patients who were outpatients and 3 who were discharged early within 7 days upon patient request were excluded. Logistic regression analysis was used to examine predictors of severe neutropenia.

Results: Of the 33 eligible patients, 24 had comorbidities, with hypertension being the most common (n = 19), followed by dyslipidemia (n = 14) and diabetes (n = 11). There was no statistically significant difference in the rate of severe neutropenia due to any of the comorbidities, depending on the presence or absence of the comorbidity. However, the rate of severe neutropenia was significantly higher in patients with baseline platelet levels < 22.4×10⁴/μL and those receiving cabazitaxel doses > 34 mg/body. In the final model adjusted for age, body mass index, C-reactive protein, and monocyte count, lower baseline platelet levels and higher doses of cabazitaxel were also predictors of the development of severe neutropenia.

Conclusion: Comorbidities such as hypertension, dyslipidemia, diabetes mellitus, cerebrovascular disease, chronic kidney disease, liver dysfunction, and cardiac disease did not affect the incidence of severe neutropenia in patients receiving cabazitaxel. The baseline platelet count and the dose of cabazitaxel were also suggested to be markers for the development of severe neutropenia.