Hongkun Xu ^1,2 Tingting Lu ³ Yajie Liu ^3* Jingqi Yang ^1* Simeng Ren ² Baojin Han ^2* Honghao Lai ^4* Long Ge ⁴ Jie Liu ^2,3*

• ¹ Beijing University of Chinese Medicine, Beijing, Beijing Municipality, China
• ² Guang’anmen Hospital, China Academy of Chinese Medical Sciences, Beijing, Beijing Municipality, China
• ³ China Academy of Chinese Medical Sciences, Beijing, Beijing Municipality, China
• ⁴ Lanzhou University, Lanzhou, Gansu Province, China

Objective: The prevalence of long COVID among cancer patients remains unknown. This study aimed to determine the prevalence of long COVID and explore potential risk factors among cancer patients.A systematic search was performed on PubMed, Web of Science, and Embase from database inception until March 21, 2024, to identify studies that reported long COVID in cancer patients. Two investigators independently screened the studies and extracted all information about long COVID in cancer patients for subsequent analysis. Methodological quality was assessed using the "Joannagen Briggs Institute (JBI) Critical Appraisal Checklist for Studies Reporting Prevalence Data".Results: A total of 13 studies involving 6653 patients were included. The pooled prevalence of long COVID was 23.52% (95% confidence interval [CI] 12.14% to 40.64%) among cancer patients reported experiencing long COVID after acute Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The pooled prevalence of any long COVID in cancer patients was 20.51% (95% CI 15.91% to 26.03%), 15.79% (95% CI 11.39% to 21.47%), and 12.54% (95% CI 6.38% to 21.18%) in 3 months, 6 months, and 12 months follow-up duration. Fatigue was the most common symptom, followed by respiratory symptoms, myalgia and sleep disturbance. Patients with comorbidities had a significantly higher risk of experiencing long COVID (odds ratio [OR] = 1.72, 95% CI 1.09 to 2.70, P = 0.019). No statistically significant differences in sex, primary tumour or tumour stage were detected.Nearly a quarter of cancer patients will experience long COVID after surviving from SARS-CoV-2 infection, and this would even last for 1 year or longer. Fatigue, respiratory symptoms, myalgia and sleep disturbance need to be more concerned and managed to reduce symptom burden on cancer patients and improve quality of life. Patients with comorbidities are at a high risk of developing long COVID. Further randomized controlled trials with rigorous methodological designs and large sample sizes are needed for future validation.