Abstract P5-10-25: Docetaxel/Cyclophosphamide (TC) Chemotherapy for Early Breast Cancer: Is Primary g-csf Prophylaxis Necessary?

Abstract

Introduction Febrile neutropenia (FN) is a recognised complication of adjuvant systemic chemotherapy which leads to hospitalisation, treatment delays and dose reductions which ultimately may compromises treatment efficacy and patient (pt) outcomes. The use of granulocyte-colony stimulating factor (G-CSF) is recommended within clinical guidelines as routine prophylaxis if the chemotherapy regimen is likely to cause FN rates of >20%.For regimens associated with FN rates of 10-20%, pt may increase the risk.(Aapro et al, 2006). Following the publication of Jones et al (2006), the Beatson West of Scotland Cancer Centre (BWOSCC) adopted TC chemotherapy as an option for patients with intermediate/high risk breast cancer as an alternative to anthracyline based regimens. This was primarily for patients who had major co-morbidities precluding anthracycline use, had prior exposure to anthracylines or who were deemed unable to tolerate a protracted course of treatment for clinical reasons. The study by Jones et al (2006) described an overall FN rate of 5% with an increased rate of FN (8%) in patients > 65 yrs, with a 4% rate in those <65yrs. Recently Soong et al (2009) reported a higher rate of FN of 50% within the first cohort of patients (6/12 pts) treated within their centre, which resulted in subsequent prophylactic G-CSF usage. A recent paper by Chan et al (2010) concluded that Asian patients who have a recognised higher incidence of Docetaxel induced myelosuppresion warranted G-CSF propylaxis. Their experience of using TC resulted in FN rates of 25% in those patients who didn't receive G-CSF, 6.3% FN rates in those who did with an absolute risk reduction of FN events by 18.7%. With this in mind, an audit of our local practice and usage of TC chemotherapy was conducted. Methods A retrospective/prospective case note review of patients treated using (neo) adjuvant TC within the BWOSCC and satellite units between October 2007 and October 2010 is being undertaken. Data in respect to the first 51 consecutive pts identified from pharmacy records, treated between October 2007 and October 2009 is available. The median age was 58 (range 27 — 81): female 50, male 1: adjuvant 50, neo-adjuvant 1. All patients received Docetaxel 75mg/m2 and Cyclophosphamide 600mg/m2 at first cycle. Results 5/51 pts (9.8%) had an episode of FN, 2 pts at cycle 1, with 1 pt at cycles 2, 3 and 4. No pt had more than 1 episode of FN.22 pts (43%) received primary G-CSF prophylaxis whilst 29pts (57%) did not. The rate of FN in the primary prophylactic group was 9% (2/22 pts) and 10% (3/29pts) in those who didn't receive G-CSF. In the G-CSF group, 1 patient required a dose reduction and 5 patients had dose delays whilst 5 patients had a dose reduction and 3 required dose delays in the non G-CSF group. Conclusion The overall rate of FN observed was approximately 10% and for a substantial proportion of patients, primary prophylaxis with G-CSF is not required. Results of ongoing data collection will be presented with regard to patient characteristics, outcomes, and indications for G-CSF primary prophylaxis in this group of patients. Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-10-25.

The Cost–Utility of Adjuvant Chemotherapy Using Docetaxel and Cyclophosphamide Compared with Doxorubicin and Cyclophosphamide in Breast Cancer

“…We assumed twice the fn risk with tc than with ac and comparable base case utilities for both regimes during the treatment period. However, in clinical practice, tc chemotherapy is perhaps more commonly used in older patients and in those with node-negative disease, and it is associated with higher fn rates and possibly with lower treatment-related utility 27,[31][32][33] . Our cost-utility estimates in those practical scenarios, and in circumstances in which primary g-csf prophylaxis is considered for all patients, were less favorable than those in the primary analysis based on clinical trial data, although they remained within commonly used cost-utility thresholds 36,37 .…”

“…The base case scenario incorporated secondary prophylaxis with granulocyte colony-stimulating factor (g-csf) after fn events and assumed no chemotherapy dose adjustments. However, outside of clinical trials, use of tc appears to be associated with higher fn rates of approximately 26% (range: 10%-46%) without and 6% (range: 0%-7%) with primary g-csf prophylaxis 27,31,32,33 . Primary prophylaxis with g-csf is also sometimes used with the tc regimen in clinical practice, because it is recommended for chemotherapeutic regimens associated with a fn risk greater than 20% 34 .…”