A retrospective evaluation of the value of COVID-19 screening and testing in patients with cancer: Aiming at a moving target

Abstract

Background: Diagnosis of COVID-19 infection in cancer patients is critical to co-manage their underlying disease and infection appropriately. Our study aimed at evaluating the sensitivity and specificity of screening patients with cancer for COVID-19 infection.

Methods: All oncology patients receiving care at Department of Oncology at King Abdulaziz Medical City in Riyadh were screened using the acute respiratory infection (ARI) survey. Nasopharyngeal and throat swap for polymerase chain reaction (PCR) testing for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was performed on patients who have high ARI score (i.e. ≥ 4), or any patient requiring elective/emergency hospitalization, undergoing a procedure as well as screening asymptomatic patients receiving chemotherapy between April 1st and July 30, 2020. Institutional Review Board approval was obtained. Descriptive and inferential analyses were done and sensitivity, specificity, positive and negative predictive values (PPV and NPV) were calculated considering the COVID-19 PCR as the gold standard.

Results: During the study period, a total of 473 patients were included with a median age was 56 years (14-104), 51% were female, 73% had solid tumors, and 66% received treatment within the last 3 months. These patients underwent 688 PCR tests along with ARI survey screening. Testing was done in the outpatient, inpatient, and emergency department setting in 41%, 40% and 19% of the patients, respectively. Majority of tests were screening of asymptomatic patients and only 23% were tested for suspected infections with ARI ≥ 4. A total of 54 patients (8%) had positive PCR for COVID-19 infection. The prevalence of infection varied from month to month ranging from 1.09% in April up to 19.70% in June and correlated with the average daily and active case load at a national level. The diagnostic yield of the ARI score also correlated with infection burden nationally. The PPV and NPV of the ARI as a screening tool was 18.24% (0-31.8) and 95.6% (86.36-98.86%) with the PPN fluctuating considerably in parallel with the prevalence of COVID-19 result. Similarly, the sensitivity and specificity of the ARI were 55.77% (0-70.59) and 79.4 (69.19-92), respectively.

Conclusion: The yield of screening asymptomatic patients with cancer varies based on the community burden of COVID-19 infection. As universal screening can cause delays to patient care, it should be tailored based on the individual patient risks and infection burden in the region.

Keywords: COVID-19; Cancer patients; Laboratory testing; RT-PCR; Screening.

Fig. 1

Percentage of COVID-19 positive cases and acute respiratory infection score on a monthly basis.