Abstract S09-04: Asymptomatic detection of COVID-19 among cancer patients receiving infusional anti-cancer therapy

Introduction Little is known about the rates of asymptomatic COVID-19 carriers among cancer patients. The rate of asymptomatic carriers is important to understand in this population given the use of myelosuppressive and immunomodulating therapies and the risk of transmission to other patients in shared infusion centers. At UC San Diego, in June 2020, we implemented a COVID-19 asymptomatic screening protocol in which cancer patients receiving anti-cancer therapy in an infusion center must undergo symptom-based screening and then SARS-CoV-2 PCR testing prior to their infusion. Here, we describe the results of this asymptomatic screening protocol. Methods This was a single-center retrospective analysis of patients with active cancer receiving infusional anti-cancer therapy in 5 infusion centers who underwent at least 1 asymptomatic SARS-CoV-2 PCR test between 6/1- 12/1/2020. The primary endpoint was the rate of COVID-19 positivity among asymptomatic patients. Symptomatic patients were excluded. Secondary endpoints included COVID-19-related outcomes and patterns of oncologic management for asymptomatic COVID-19 positive patients. Results A cohort of 2,202 cancer patients received at least 1 asymptomatic SARS-CoV-2 PCR test prior to receipt of infusional anti-cancer therapy. 0.95% (N=21/2202) of patients were found to be PCR-positive on asymptomatic screening. Among positive patients, 9.5% (N=2/21) had hematologic malignancies and 90.5% (N=19/21) had solid tumors. In terms of therapy, 76.2% (N=16) were treated with cytotoxic chemotherapy, 9.5% (N=2) with targeted therapy, 4.7% (N=1) with immunotherapy, and 9.5% (N=2) were on a clinical trial. With a median follow-up of 122 days from positive PCR test (range: 8-186), only 2 of 21 (9.5%) of the cohort ultimately developed COVID-related symptoms. Both patients had a diagnosis of acute leukemia and 1 patient required hospitalization for COVID-related complications. No patients died from COVID-related complications. With regards to oncologic management, 95.2% (N=20/21) of patients had their therapy delayed or deferred with a median delay of 21 days (range: 7-77 days). Only 1 patient proceeded with cytotoxic chemotherapy on schedule in the setting of adjuvant chemoradiation for oropharyngeal squamous cell carcinoma. Among the overall cohort, an additional 26 patients (1.2%) developed cases of symptomatic COVID-19 infection during the study period. Conclusions A strategy of asymptomatic screening of cancer patients receiving anti-cancer therapy in an infusion center detected an extremely low rate of asymptomatic carriers of COVID-19. This low rate of asymptomatic carriers may be due to a number of factors including multiple symptom-based screenings prior to infusion, behavior modification among patients, and/or differential immune responses to COVID-19 infection. Asymptomatic carriers in this cohort appeared to have favorable outcomes with few developing symptoms or requiring hospitalization, though the number of positive patients in our cohort is low, precluding definitive conclusions in this population. Citation Format: Justin A. Shaya, Angelo Cabal, Francesca Torriani, Joseph Califano, Scott Lippman, Assuntina Sacco, Rana R. McKay. Asymptomatic detection of COVID-19 among cancer patients receiving infusional anti-cancer therapy [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr S09-04.