Risk of febrile neutropenia in patients receiving emerging chemotherapy regimens.

Purpose: Considerable evidence exists concerning the risk of febrile neutropenia (FN) associated with well-established, older chemotherapy regimens. Little is known, however, about the risks associated with many regimens that were introduced in the past decade and have become the predominant choice for certain cohorts of patients or are increasingly being used in clinical practice.

Methods: A retrospective cohort design and US healthcare claims data (2006-2011) were employed. Study subjects included adult patients receiving the following: docetaxel + cyclophosphamide (TC), 5-FU + epirubicin + cyclophosphamide (FEC), FEC followed by docetaxel (FEC → D), or docetaxel + carboplatin + trastuzumab (TCH) for non-metastatic breast cancer; TCH for metastatic breast cancer; 5-FU + leucovorin + irinotecan + oxaliplatin (FOLFIRINOX) for metastatic pancreatic cancer; and bendamustine (with rituximab [BR], without rituximab [B-Mono]) for non-Hodgkin's lymphoma (NHL). For each patient, the first qualifying chemotherapy course and each cycle therein were identified, as were the use of supportive care-colony-stimulating factors (CSF) and antimicrobials (AMB)-and unique FN episodes.

Results: The crude risk (incidence proportion) of FN during the chemotherapy course ranged from 8.8 (95 % CI 8.3-9.3) to 10.6 % (9.3-12.1) among the breast cancer regimens, was slightly higher for the NHL regimens (BR, 10.5 % [8.9-12.4]; B-Mono, 14.7 % [11.2-18.9]), and was markedly higher for FOLFIRINOX (24.7 % [17.9-33.1]). Most patients developing FN required inpatient care (range, 73-90 %). Use of CSF primary prophylaxis ranged from 17 (B-Mono) to 75 % (FEC → D); use of AMB primary prophylaxis ranged from 6 (FOLFIRINOX) to 13 % (B-Mono).

Conclusion: The risk of FN among patients receiving selected emerging chemotherapy regimens is considerable, and most cases require inpatient care. Use of CSF and AMB prophylaxis, however, varies substantially across regimens.