Impact of COVID-19 Vaccination and Prior Infection on Survival Outcomes in Patients with Metastatic Solid Tumors
Önder Bağcı1, Levent Korkmaz2, Mehmet Zahid Koçak31Department of Medical Oncology, Konya City Hospital, Konya, Türkiye, 2Department of Computer Engineering, İstinye University Faculty of Engineering İstanbul, Türkiye, 3Department of Medical Oncology, Necmettin Erbakan University, Meram Faculty of Medicine, Konya, Türkiye
Objectives: To assess the effect of prior SARS-CoV-2 infection and COVID-19 vaccination on overall survival (OS) in patients with metastatic solid tumors and to examine potential variation in this association across major cancer subtypes. Methods: This retrospective observational study included 62 patients with histologically confirmed metastatic solid tumors. Patients were categorized into four groups according to vaccination and infection status: vaccinated and previously infected, vaccinated only, infected only, and unvaccinated/uninfected controls. Results: OS was longer in vaccinated or previously infected patients than in double-negative controls (51.4 months vs. 33.8 months) (p=0.324). Among patients in remission, survival was markedly longer in those with prior vaccination or COVID-19 infection than in individuals negative for both factors (90 vs. 36 months), although this difference did not reach statistical significance (p=0.302). The most pronounced benefit occurred within the breast cancer subgroup, where prior infection or vaccination was strongly associated with extended remission survival (106 months). Conclusion: Prior COVID-19 infection and vaccination were associated with improved long-term survival in patients with metastatic solid tumors. These observations raise the possibility that immune activation triggered by viral exposure or vaccination may enhance tumor immunosurveillance and strengthen host resilience. Keywords: COVID-19, Metastatic Cancer, Vaccination
Cite This Article
Bağcı Ö, Korkmaz L, Koçak M. Impact of COVID-19 Vaccination and Prior Infection on Survival Outcomes in Patients with Metastatic Solid Tumors. EJMI. 2026; 10(2): 118-123
Corresponding Author: Mehmet Zahid Koçak