Risk Factors for Febrile Neutropenia among Breast, Lung, and Colorectal Cancer Patients: A Retrospective Analysis of Health Plan Databases

Chemotherapy regimens, patient factors, and the use of colony stimulating factor (CSF) influence cancer patients’ risk for febrile neutropenia (FN) when they receive myelosuppressive chemotherapy. The incidence of FN and patient factors influencing that risk are relatively unknown in community settings. Using claims from Medicare, Medicaid and two private health insurance plan enrollees linked to the Puget Sound SEER registry, we examined the incidence of FN among breast, lung and colorectal cancer patients diagnosed 2002–05 who received adjuvant chemotherapy. We used logistic regression models to determine factors influencing the risk for FN within the first chemotherapy cycle, controlling for cancer stage, age, sex, race, comorbidities, chemotherapy-regimen related FN risk (as designated by the National Comprehensive Cancer Network), CSF use, health insurance type, and surgery or radiation ≤30 days from administration of first chemotherapy. Over the time horizon, 1096 breast, 1142 lung, and 755 colorectal cancer patients received chemotherapy. The incidence of any FN in the first chemotherapy cycle was (counts per 100 recipients by high, intermediate, and low-risk myelosuppressive chemotherapy according to NCCN categories respectively) 7.36, 10.0, 4.70 for breast cancer, 17.12, 14.15, 12.22 for lung cancer, and 25.0, 8.96, 6.37 for colorectal cancer. Significant predictors (p<0.05) of any FN were: breast cancer—radiation ≤ 30 days from first chemotherapy administration (OR 2.90, 95% CI 1.21–6.94), other non-black race vs. white race (OR 2.82, 95% CI 1.29–6.17), or Medicaid insurance (OR 2.31, 95% CI 1.10–4.89); lung cancer—radiation ≤ 30 days from first chemotherapy administration (OR 1.63, 95% CI 1.01–2.61), surgery ≤ 30 days from first chemotherapy administration (OR 2.08, 95% CI 1.02–4.25), Medicaid insurance (OR 2.29, 95% CI 1.08–4.84), or a Charlson comorbidity score ≥ 2 (OR 2.56, 95% CI 1.11–5.91); colorectal cancer—female gender (OR 1.86, 95% CI 1.02–3.41) or high myelosuppressive risk chemotherapy regimen (OR 7.66, 95% CI 2.95–19.89). In this analysis, predictors of FN varied between cancers. Limitations of this analysis include lack of information about chemotherapy and CSF doses, as this is not captured in the SEER registry or claims data. These results indicate that several factors may interact to influence a patient’s likelihood of developing FN in the first cycle of adjuvant chemotherapy.