A retrospective study to evaluate the efficacy and safety of SARS-CoV-2 vaccine in patients with advanced genitourinary cancers.

ABSTRACT

Background: COVID-19 vaccination is one of the pivotal key tools against the ongoing pandemic, but its acceptance relies on efficacy and safety data among various populations, including patients with cancers. However, there is limited data on seroconversion rates, efficacy, and safety of the COVID-19 vaccine in patients with cancer. Breakthrough infections after vaccination have also been reported, which could further strengthen the refusal behavior of specific populations to be immunized. Our objective was to investigate the efficacy and safety of COVID-19 vaccination in real-world patients with advanced genitourinary cancers. Methods and results: A retrospective study of the 738 patients with advanced metastatic genitourinary malignancy was conducted at our genitourinary oncology clinic from October 2020 to September 2021, out of which 462 patients (62.6%) were vaccinated. During the study period, two vaccinated, and six unvaccinated patients tested positive for SARS-CoV-2 (breakthrough infection rate 0.4% vs. 2.2%, p = 0.027). Vaccine protection against infection was 81.8% (95% CI 0.04-0.98). One vaccinated and 4 unvaccinated patients were hospitalized due to COVID-19 (0.2% vs. 1.4%, p = 0.048). Vaccine effectiveness in preventing hospitalization was 85.7% (95% CI 0.02-1.33). Within one month of vaccination, 1.5% of patients (n = 7) had emergency visits, 0.8% (n = 4) were hospitalized for any reason, and of these, 3 (0.6%) experienced a delay in the receipt of their cancer therapy. Conclusion: In our hypothesis-generating data among patients with advanced genitourinary cancers, COVID-19 vaccination was efficacious and safe and was rarely associated with treatment disruptions. These data should help improve the acceptance of the COVID-19 vaccine in the general population and patients with cancer. The vaccine effectiveness in our patients is comparable with existing published data without cancer.