RESUMO
Dose-dense (DD) chemotherapy is a treatment option for patients with high-risk premenopausal breast cancer. Pegfilgrastim may be administered as prophylaxis against the development of febrile neutropenia and enables the continuation of the DD schedule; however, it is associated with adverse effects, including bone and muscle pain and fatigue. We herein describe our experience with pegfilgrastim administration alongside DD chemotherapy in a patient with breast cancer. A 29-year-old female patient was diagnosed with locally advanced breast cancer during lactation. The patient was diagnosed with cT2N1M0, stage IIB triple-negative breast cancer and underwent four cycles of DD chemotherapy with epirubicin plus cyclophosphamide, followed by four cycles of docetaxel (DTX) every 2 weeks preoperatively, with 3.6 mg pegfilgrastim administered subcutaneously on day 3 of each cycle. The absolute neutrophil count (ANC) was 2,700, 8,400, 11,100, 13,300 and 15,000/mm3 on day 1 of each cycle. The patient experienced fatigue after each pegfilgrastim injection and was considered to be a high responder to pegfilgrastim. Therefore, 1.8 mg pegfilgrastim on day 3 of the first DD-DTX cycle was recommended. On day 1 of the second cycle, the ANC was 13,090/mm3. The patient experienced less fatigue after the administration of 1.8 mg pegfilgrastim, but there was a significant decline in her performance status. As there is currently no evidence of pegfilgrastim dose reduction to below 1.8 mg, pegfilgrastim was omitted on day 3. On day 14, the patient developed viral enteritis, fever (38°C), and an ANC of 297/mm3. Therefore, the third cycle was postponed. After 1 week, the patient's ANC recovered to 2,480/mm3 and she was administered the third cycle with 3.6 mg pegfilgrastim on day 3. Between January 2015 and March 2018, a total of 55 patients with breast cancer received chemotherapy with pegfilgrastim at the Shiga General Hospital. No patients other than the one presented herein experienced leukocytosis during chemotherapy. Although this was a rare complication, a dose of 1.8 mg pegfilgrastim was effective in palliating the patient's symptoms and preventing DD chemotherapy discontinuation.
RESUMO
BACKGROUND: Sunitinib has been approved for the treatment of metastatic renal cell carcinoma (RCC). Sunitinib pharmacokinetics shows a large interpatient variability. PATIENTS AND METHODS: A retrospective, observational clinical study of 21 patients with RCC was performed. Sunitinib was administered for 4 weeks of a 6-week cycle for the first cycle. We evaluated the association of sunitinib-induced toxicities and clinical outcomes with the trough total sunitinib concentration in a steady state during the first cycle. RESULTS: The median total sunitinib concentration was 91.8 ng/mL (range, 49.8-205 ng/mL). There was an association between total sunitinib concentration and the severity of thrombocytopenia, anorexia, and fatigue. Patients with ≥ 100 ng/mL total sunitinib (n = 8), compared with patients with < 100 ng/mL (n = 13), had a greater incidence of Grade ≥ 3 toxicities (6 patients [75.0%] vs. 3 patients [23.1%]). Patients with < 100 ng/mL total sunitinib had significantly longer time to treatment failure (TTF) and progression-free survival (PFS) time than patients with ≥ 100 ng/mL (median TTF, 590 vs. 71 days; P = .04; median PFS, 748 vs. 238 days; P = .02). CONCLUSION: Results of this study suggest that therapeutic drug monitoring of sunitinib could be useful for avoiding severe toxicities. Dose reduction might be needed, especially when the total sunitinib concentration is ≥ 100 ng/mL, to avoid unnecessary early discontinuation of treatment.