Importance of Risk Factors for Febrile Neutropenia Among Patients Receiving Chemotherapy Regimens Not Classified as High-Risk in Guidelines for Myeloid Growth Factor Use.
BACKGROUND
Clinical practice guidelines recommend prophylaxis in patients with cancer receiving a colony-stimulating factor (CSF) when the risk of febrile neutropenia (FN) is high (>20%). For patients receiving chemotherapy regimens not documented as high-risk, the decision regarding CSF prophylaxis use can be challenging, because some patients may be at high risk based on a combination of the regimen and individual risk factors.


METHODS
A retrospective cohort design and US private health care claims data were used. Study subjects received chemotherapy regimens classified as "low" or "intermediate," or unclassified, in terms of FN risk, and were stratified by cancer and regimen. For each subject, the first chemotherapy course, and each cycle and FN episode within the course, were identified. FN incidence proportions were estimated by the presence and number of risk factors and chronic comorbidities.


RESULTS
Across the 17 tumor/regimen combinations considered (n=160,304 in total), 74% to 98% of patients had 1 or more risk factor for FN and 41% to 89% had 2 or more. Among patients with 1 or more risk factor, FN incidence ranged from 7.2% to 29.0% across regimens, and the relative risk of FN (vs those without risk factors) ranged from 1.1 (95% CI, 0.8-1.3) to 2.2 (95% CI, 1.5-3.0). FN incidence increased in a graded and monotonic fashion with the number of risk factors and comorbidities.


CONCLUSIONS
In this retrospective evaluation of patients with cancer receiving chemotherapy regimens not classified as high-risk for FN in US clinical practice, most patients had 1 or more FN risk factor and many had 2 or more. FN incidence was found to be elevated in these patients, especially those with multiple risk factors.
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Derek
D
Weycker
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Xiaoyan
X
Li
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Rich
R
Barron
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Hongsheng
H
Wu
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
P K
PK
Morrow
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Hairong
H
Xu
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Maureen
M
Reiner
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Jacob
J
Garcia
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Shivani K
SK
Mhatre
From Policy Analysis Inc. (PAI), Brookline, Massachusetts; Amgen Inc., Thousand Oaks, California; Department of Pharmaceutical Health Outcomes and Policy, College of Pharmacy, Texas Medical Center, University of Houston, Houston, Texas; and Hutchinson Institute for Cancer Outcomes Research, Fred Hutchinson Cancer Research Center, University of Washington, Seattle, Washington.
Gary H
GH
Lyman
D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D015897:Comorbidity; D064147:Febrile Neutropenia / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology*; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000627:therapeutic use; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D008297:Male; D009369:Neoplasms / Q000150:complications* / Q000188:drug therapy; D012189:Retrospective Studies; D012307:Risk Factors
D016179:Granulocyte Colony-Stimulating Factor; D016178:Granulocyte-Macrophage Colony-Stimulating Factor