SARS-CoV-2 Infection and Its Effects on Toxicity and Survival in Non-Metastatic Nasopharyngeal Carcinoma: A Matched Cohort Study

Background: This study investigated the impact of SARS-CoV-2 infection on treatment-related adverse events (TRAEs) and 2-year survival outcomes in patients with newly diagnosed non-metastatic nasopharyngeal carcinoma (NPC) treated with radiotherapy alone or in combination with chemotherapy. Methods: In this retrospective cohort study, 1,108 NPC patients diagnosed between May 2020 and March 2023 were included. Patients were categorized into a SARS-CoV-2-infected group (infection during chemotherapy or during/within 2 weeks after radiotherapy) and an uninfected group. Propensity score matching was performed to minimize selection bias. Primary endpoints were acute and late TRAEs; secondary endpoints included 2-year overall survival (OS), progression-free survival (PFS), distant metastasis-free survival (DMFS), and locoregional relapse-free survival (LRRFS). Results: After matching, 211 pairs were analyzed. The 2-year OS (96.2% vs. 97.6%; P = 0.403), PFS (88.6% vs. 90.5%; P = 0.558), DMFS (92.4% vs. 91.5%; P = 0.720), and LRRFS (92.4% vs. 96.2%; P = 0.099) were similar between groups. However, SARS-CoV-2-infected patients had higher rates of leukopenia during induction chemotherapy (39.8% vs. 28.9%; P = 0.044) and hepatic impairment during both induction chemotherapy (49.3% vs. 36.0%; P = 0.044) and radiotherapy (26.9% vs. 12.2%; P = 0.001). Cox regression confirmed that SARS-CoV-2 infection was not an independent predictor of survival outcomes. Conclusions: SARS-CoV-2 infection during anticancer therapy in non-metastatic NPC patients was associated with increased hematologic and hepatic toxicities but did not adversely affect 2-year survival outcomes.