3495 - The Importance of Lymphopenia Severity in Anal Cancer Patients Undergoing Definitive Therapy
Presenter(s)
Y. R. Wuu1,2, D. Myagmarsuren3, B. Gui1,2, K. Chahal4, D. J. Cooper5, J. M. Herman1,2, and L. Tchelebi1,6; 1Northwell, New Hyde Park, NY, 2Department of Radiation Medicine, Northwell, New Hyde Park, NY, 3Virginia Tech Carilion School of Medicine, Roanoke, VA, 4SUNY Downstate College of Medicine, New York, NY, 5Department of Otolaryngology, SUNY Downstate, New York, NY, 6Department of Radiation Medicine, Northern Westchester Hospital, Mount Kisco, NY
Purpose/Objective(s): The neutrophil-to-lymphocyte ratio (NLR) and treatment-related lymphopenia (TRL) have been shown to have a prognostic role in patients with solid tumors undergoing definitive chemoradiotherapy (CRT); however, the literature remains limited in anal cancer. This study investigates the prognostic significance of NLR, TRL, and sociodemographic factors on overall survival (OS) in anal cancer patients.
Materials/Methods: A retrospective review of anal cancer patients treated with definitive CRT between 2014 – 2024 was completed. Baseline clinical characteristics, pretreatment neutrophil/lymphocyte counts, NLR, and lymphocyte nadir during treatment were collected. A high NLR was classified as >3. Sociodemographic data (i.e. gender, race, marital status, and income) were obtained from patient and census records. OS was estimated using Kaplan-Meier analysis and compared using the log-rank test. Predictors of grade 3 lymphopenia were analyzed with multivariate logistic regression; univariate and multivariate Cox regression analysis identified OS predictors.
Results: Following IRB approval, 213 patients with anal cancer who underwent radiation therapy were identified. Patients were excluded if they did not receive definitive CRT using IMRT or had non-squamous cell histology –179 patients (74.9% female, 67.0% non-Hispanic white) were included in the study. The median dose received was 54Gy (range 41.4 – 56Gy) and 152 (84.9%) patients experienced grade 3+ lymphopenia; 55 (30.7%) patients experienced grade 4 lymphopenia. Grade 3+ lymphopenia was associated with female gender (OR: 3.36, 95% CI: 1.24 – 9.10, p = 0.02), but not with race or household income (p = 0.8, 0.4, respectively). A high NLR (=3) was associated with a positive trend towards worse 5-year OS (80.1% vs 91.4%, p = 0.06). 52 (29%) patients had a =90% decrease in lymphocyte count. A =90% vs. <90% decrease from lymphocyte baseline to nadir had a worse 5-year OS of 80.1% vs 91.4%, respectively (p = 0.02). On univariate analysis, OS was associated with pretreatment white blood cell (WBC) count, absolute neutrophil count (ANC), KPS, and =90% decrease in lymphocytes (HR: 1.3, 1.2, 2.8, 0.9 and p = 0.0002, 0.002, 0.03, 0.008, respectively), but not with grade 3+ lymphopenia, race, gender, and income (p = 0.6, 0.9, 1.0, 0.8, respectively). On multivariate analysis, =90% decrease in lymphocytes and KPS were associated with OS (HR: 3.3 and 0.9 and p = 0.048, 0.047, respectively).
Conclusion: Lymphocyte count and lymphocyte nadir (=90% from baseline) may serve as a prognosticator for overall survival. Patients with an elevated NLR =3 may predict poorer outcomes. There was no association between sociodemographic factors and treatment outcomes.