Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2017

A decade of G-CSF prescribing during curative chemotherapy for early breast cancer: what trends are changing? (#180)

Zoe Loh 1 , Jim Siderov 2 , Belinda Yeo 1 3
  1. Department of Medical Oncology, Olivia Newton John Cancer Research & Wellness Centre, Austin Health, Melbourne, VIC, Australia
  2. Pharmacy Department, Austin Health, Melbourne, VIC, Australia
  3. Olivia Newton John Cancer Research Institute, Melbourne, VIC, Australia

The use of granulocyte colony stimulating factor (G-CSF) during polychemotherapy regimens has been increasing. International guidelines recommend primary prophylaxis when the risk of neutropenic complications exceeds 20% and as a result, G-CSF is often used outside of PBS reimbursement via various funding models. The aim of this audit was to evaluate the use of G-CSF over the past decade in a series of early breast cancer patients treated in an Australian tertiary hospital.

We retrospectively identified patients receiving (neo)adjuvant chemotherapy for early breast cancer in two cohorts: “early” 2005-10 and “late” 2011-16 at Austin Health. Chemotherapy regimens, G-CSF use and schedule were compared along with rates of febrile neutropenia (FN) for the 2011-16 cohort.

Between 2005-2016, 655 patients received the following curative chemotherapy regimens: 103 (16%) anthracycline-based (FEC), 171 (26%) taxane-based (TC = 147; TcarboH = 34) and 371 (57%) combined regimens (FEC-D = 169; AC-T (+/-H) = 191); TAC = 11). A similar proportion of patients received PBS-qualifying primary prophylaxis (10% versus 9% respectively). There was a substantial increase in G-CSF use over time with 61% (all using pegfilgrastim) in the early compared with 90% (52% pegfilgrastim and 48% filgrastim) in the late cohort. Thirty patients who initially received filgrastim were subsequently changed to pegfilgrastim at a later cycle. Fifty-four (19%) early cohort patients received G-CSF from cycle 1 compared with 266 (73%) in the late cohort. Thirty-one (9%) patients had a febrile neutropenic event in the late cohort, 21 (69%) of whom were already receiving G-CSF. The rate of FN was stable year on year from 2011-16.

G-CSF use has increased substantially over the past decade despite no increase in the prescribing of our most myelosuppressive regimens. Increasing availability and fall in cost of short-acting preparations have diversified prescribing.