SARS-CoV-2 Seroprevalence among Solid Tumor Outpatients in a Spanish Hospital - Abstract
Background: Cancer patients are highly vulnerable to SARS-CoV-2 infection and the risk-benefit of active cancer treatment should be evaluated if infection occurs. Thus, it was of interest to assess the SARS-CoV2 infection prevalence among cancer outpatients (by means of serology), and to evaluate if appropriate treatment modifications are taking place according to serological status. Patients and Methods: An observational, ambispective study was conducted in the Medical Oncology unit of Basurto University Hospital to assess the seroprevalence of SARSCov2 among adult outpatients with solid tumors who visit the unit for active treatment or follow-up. In addition, the possible implications of seropositivity on oncologic care were also assessed. Total antibodies were assessed by Chemiluminescence Immunoassay (CLIA), and when positive, followed by IgG and IgM Enzyme Linked Immunosorbent Assay (ELISA), at baseline and serially up to 12 months, and SARS-CoV-2 RT-PCR was performed at baseline, and for those patients on treatment, also at 24-48 hours before treatment cycle initiation. Results: Out of 515 eligible patients, 31 were positive for SARS-Cov2 infection (seroprevalence: 5.6%). Contact with a COVID-19 positive patient, history of smoking and hypertension were risk factors for the infection. Five (23.8%) patients underwent a modification of their treatment plan (3, treatment delay and 2, treatment suspension). Conclusion: Serology by CLIA and ELISA is a sensitive and specific method for establishing SARS-Cov2 infection status in the oncologic population. Prevalence of infection is 6% among solid tumor outpatients. Antineoplastic therapy is modified in more than a quarter of patients positive to the infection.