Chemotherapy-associated neutropenia with same-day versus next-day pegfilgrastim in outpatient chemotherapy: solid...

To compare the incidence of febrile neutropenia (FN) and chemotherapy delays (CD) due to neutropenia in chemotherapy cycles in which pegfilgrastim (PGF) was administered on the same day (D0) vs the following day (D+1), as treatment for solid tumours.

A retrospective cohort study was conducted using the number of chemotherapy cycles with PGF administration as the unit of analysis. PGF administration on D0 was compared with administration on D+1. The incidence of FN and CD was calculated for the entire cohort and for subgroups. Relative risk (RR) between groups was assessed, a p value <0.05 considered statistically significant.

A total of 1091 cycles with PGF administration on D0 were compared with 1089 cycles on D+1. The incidence of FN was 1.6% in D0 and 0.5% in D+1 (RR=3.4; p=0.02), and CD was 2.2% and 2.6% in D0 and D+1, respectively (RR=0.9; p=0.67). The incidence of FN on breast cancer (BC) patients was 2.4% in D0 and 0.3% in D+1 (RR=7.0; p<0.01). No significant differences were identified in the incidence of FN among other tumours (OT) (RR=1.0; p=0.68).

Higher rates of FN were observed in the overall cohort when PGF was administered on D0, largely influenced by the subgroup of BC patients. Among OT, the day of PGF administration did not impact the outcome. These findings support the administration of PGF on D+1 of chemotherapy in BC patients when FN prevention is the objective. For patients with OT, administration of PGF on D0 is considered appropriate.