Audit of prophylactic antibiotics and growth factor prescribing in sarcoma patients receiving chemotherapy with a febrile neutropenia rate greater than 20

Background: Systemic anti-cancer therapy (SACT) regimens used for sarcomas are some of the most intensive used in solid tumours Febrile neutropenia (FN) is arguably the most significant complication from SACT FN may lead to treatment delays and dose reductions, which may compromise dose intensity, and have a detrimental impact on efficacy outcomes For regimens carrying an absolute FN risk <20%, current guidance supports the use of granulocyte-colony stimulating factor (GCSF) with every cycle (regardless of the occurrence of FN at any point during their treatment) Conversely, prophylactic antibiotics are recommended on cycle 1 and are only to be reintroduced if further FN episodes occur with subsequent cycles 1,2 Objective: To evaluate the adherence to national and local guidelines on the management of GCSF and prophylactic antibiotics in sarcoma patients undergoing SACT with FN rate of <20% Methodology: Retrospective study conducted between February and May 2020 in adult and paediatric patients receiving the following regimes for soft tissue, bone, Ewing's sarcoma or rhabdomyosarcoma: MAP, DOX75/IFOS 9, VDC/IE, or treated according to the RMS 2005 trial protocols Data collected: age, SACT regimen, allergy status, if ciprofloxacin prescribed (at cycle 1 and 2) and prescription details, if filgrastim prescribed and prescription details and if patients had FN with cycle 1 Exclusion criteria: paediatric patients treated elsewhere during the COVID-19 pandemic Audit standards included: S1- 100% of patients receiving ciprofloxacin (500mg BD d7-15) unless penicillin/ quinolone allergy/resistance;S2- 100% of patients experiencing FN post-cycle #1 continue antibiotics for cycle 2, and antibiotics stopped in those who did not have FN;S3- 100% of patients receive GCSF (5-10 days commencing 24-72 h post-chemotherapy with cycles 1 & 2) Results: Twenty-one patients met the eligibility criteria, mean age 23 4 years and 33 3% of patients female (see Table 1 for baseline characteristics) S1: 73 5% of patients were prescribed ciprofloxacin with cycle 1 (in 9 5% of them starting dates and duration followed guidance);6 patients (28 5%) did not receive ciprofloxacin (with no documentation of allergy/ resistance) S2: 15 patients audited (6 excluded as did not meet S1), of which: 4 patients (26 6%) had the correct action taken for their second cycle vs 11 (73 3%) who did not (no FN at cycle 1 and continued on antibiotics inappropriately) S3: 20 patients (95 2%) were prescribed filgrastim for their first and second cycle, and 1 patient (4 7%) was prescribed peg-filgrastim Conclusion: This study found marked differences in adherence to guidelines between antibiotics and GCSF prescribing: whilst the totality of patients received GCSF support with their two cycles, this decreased to ∼75% of patients being prescribed prophylactic antibiotics (in∼10% starting dates and duration exactly matched guidelines) Reasons for the comparatively low rate of antimicrobial prescribing may rely on prescriber preferences, treatment intent, performance status, or ciprofloxacin not pre-built into SACT regimens Nonetheless, the relatively small patient numbers make it difficult to ascertain these factors Additionally, 73% of patients had the incorrect action taken (discontinue if no FN vs continue if previous FN) for cycle 2