Association of COVID-19 with Features of the Peripheral Hemogram Among Cancer Patients Undergoing Chemotherapy Objectives: Future pandemics involving COVID-19 or other respiratory disorders may pose risks to treatment out- comes among cancer patients on chemotherapy. Here we explored whether diagnosis with COVID-19 might infuence how chemotherapy alters the peripheral hemogram of cancer patients. To examine changes in the peripheral hemo- gram before and after chemotherapy depending on whether patients were unexposed to the SARS-CoV-2 virus, had COVID-19, or were recovering from COVID-19. Methods: We retrospectively reviewed the records of 8,900 patients with solid cancers who underwent chemotherapy between October 10, 2022 and March 1, 2023. We compared hemograms before and after chemotherapy within and across the following three groups: 3,215 patients previously unexposed to SARS-CoV-2, 2,771 patients with COVID-19, and 2,817 patients recovering from COVID-19. We compared counts of white blood cells, red blood cells, and platelets as well as percentages of neutrophils between the frst blood sampling after admission and the frst sampling after conclusion of chemotherapy. Results: Of the various parameters examined, only the changes in counts of white blood cells and platelets difered signifcantly across the three patient groups. White blood cell count before chemotherapy was lower in patients with COVID-19 than in those unexposed to the virus or those recovering from COVID-19. Platelet count after chemotherapy was lower in patients with COVID-19 than in those recovering from COVID-19. Chemotherapy reduced the red blood cell count and increased the neutrophil percentage in all three patient groups, with the largest changes occurring in patients with COVID-19; however, these changes did not achieve statistical signifcance. Conclusion: These studies suggest that COVID-19 does not signifcantly alter the peripheral hemogram of cancer pa- tients who receive efective chemotherapy. Keywords: COVID-19, tumor chemotherapy, peripheral hemogram Jia-Yong Su, 1# Zhen-Jie Guo, 2# Yao-Hong Liu, 1 Qiong-Mei Li, 3 Yan-Jun Li, 1 Bing-Hua Chen, 1 Yu-Ling Zhao, 1 Bin-Yuan Mo, 1 De-Shen Chen, 1 Yu-Ni Li, 1 Yu-Tong Cai, 1 Qing-Qing Chen, 4 Jian-Hong Zhong 1,5 1 Department of Hepatobiliary Surgery, Guangxi Medical University Cancer Hospital, Nanning, China 2 Medical Records Room, Guangxi Medical University Cancer Hospital, Nanning, China 3 Nursing College of Guangxi Medical University, Nanning, China 4 Guangxi Crucial Laboratory of AIDS Prevention and Treatment & School of Public Health, Guangxi Medical University, Nanning, China 5 Key Laboratory of Early Prevention and Treatment for Regional High Frequency Tumors (Guangxi Medical University), Ministry of Education, Nanning, China # Jia-Yong Su and Zhen-Jie Guo contributed equally to this work. Abstract DOI: 10.14744/ejmo.2023.18762 EJMO 2023;7(3):255–264 Research Article Cite This Article: Su JY, Guo ZJ, Liu YH, Li QM, Li YJ, Chen BH, et al. Association of COVID-19 with Features of the Peripheral Hemogram Among Cancer Patients Undergoing Chemotherapy. EJMO 2023;7(3):255–264. Address for correspondence: Jian-Hong Zhong, MD. Department of Hepatobiliary Surgery, Guangxi Medical University Cancer Hospital, He Di Rd. #71, Nanning 530021, P.R. China Phone: +86-771-5330855 E-mail: zhongjianhong@gxmu.edu.cn Submitted Date: July 22, 2023 Accepted Date: August 17, 2023 Available Online Date: October 06, 2023 © Copyright 2023 by Eurasian Journal of Medicine and Oncology - Available online at www.ejmo.org OPEN ACCESS This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.