Low Baseline Absolute Neutrophil Count and Chemotherapy Safety in African American Patients with Advanced Lung Cancer: A Retrospective Cohort Study.

INTRODUCTION

African American patients remain underrepresented in cancer clinical trials, and minimum absolute neutrophil count (ANC) eligibility thresholds may disproportionately exclude individuals with Duffy-null associated neutrophil count (DANC), a common biologic variant associated with lower baseline ANC and no clearly increased infection risk. We evaluated whether African American patients with advanced lung cancer and lower baseline ANC experience greater chemotherapy-related complications.

METHODS

We conducted a retrospective cohort study of African American patients with stage IV lung cancer receiving first-line chemotherapy at a single center. Patients were grouped by baseline ANC (≤ 2500 vs. > 2500 cells/µL) as a pragmatic proxy for potential DANC. We collected demographic, clinical, and ANC data at baseline, end of cycle 1, and nadir during the first 4 chemotherapy cycles, comparing infectious complications, febrile neutropenia, antibiotic and growth factor use, and dose modifications between the groups.

RESULTS

Among 127 eligible patients, 9 (7.1%) had baseline ANC ≤ 2500 cells/μL. These patients had more severe post-treatment neutropenia (P = .004) and a lower median ANC nadir (P = .05) compared to those with baseline ANC > 2500 cells/µL. No significant differences were observed in infection rates, febrile neutropenia, antibiotic use, or growth factor use.

CONCLUSION

Lower baseline ANC was associated with greater neutropenia severity but not increased infectious complications in African American patients with advanced lung cancer. These findings suggest uniform ANC-based eligibility thresholds merit reconsideration, supporting prospective studies incorporating Duffy status to promote equitable trial eligibility and toxicity management.