ABSTRACT
Background: The SARS-CoV-2 Omicron pandemic had a global impact on individuals with cancers. This study aimed to investigate the effect of Omicron infection on cancer patients in China. Methods: A retrospective study was conducted, including 347 patients with cancer who received radiotherapy or chemoradiotherapy between July 2022 and March 2023. The patients were divided into three groups: those without SARS-CoV-2 infection during treatment (Non-COVID-19 group), those who began treatment at least 10 days after first testing positive for SARS-CoV-2 (≥10-d COVID-19 group), and those who began treatment less than 10 days after first testing positive for SARS-CoV-2 (<10-d COVID-19 group). The serum levels of SAA, hsCRP, ALT, etc, were used to assess the severity of inflammation, liver damage, and cardiovascular injury. Results: The proportion of moderate and severe infected cases was higher in ≥10-d COVID-19 group compared with <10-d COVID-19 group (p=0.0446). Additionally, the serum levels of SAA, hsCRP, IL-6 and PCT, were significantly higher in ≥10-d COVID-19 group (p<0.05). Serum ALT, LDH and HBDH levels were also elevated in ≥10-d COVID-19 group (p<0.05). However, no significant differences were observed in frequency of neutropenia, thrombocytopenia and completion rates among three groups. Conclusion: Omicron infection leads to inflammation, liver damage and cardiovascular injury in cancer patients. Surprisingly, the duration of delay in radiotherapy or chemoradiotherapy after Omicron infection did not affect completion rates of current therapy, which was not consistent with the recommendations of NCCN guidelines. Moreover, the severity of Omicron infection was worse among cancer patients who received delayed treatment.