Accumulating data suggest that patients with cancer are more vulnerable to coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and that those infected may have poor outcomes. COVID-19 diagnosis is established based on the detection of SARS-CoV2 in nasopharyngeal samples using a reverse transcriptase-polymerase chain reaction (RT-PCR) test. Most patients with COVID-19 develop antibodies against the SARS-CoV2 proteins, and these antibodies can be measured with serological tests.

In France, at the Centre Léon Bérard in Lyon, a retrospective analysis was conducted of 85 patients with cancer who presented with suspected COVID-19 from March 1 to April 16, 2020 and 244 healthcare workers (doctors and nurses) who participated as part of a voluntary testing procedure. All 85 patients were tested with RT-PCR and a point-of-care antibody diagnostic test (Toda Coronodiag®), a rapid lateral flow immunoassay (LFIA), which provides results in 10 minutes using a finger-prick blood sample. This test was performed ≥ 15 days after a positive RT-PCR test or symptoms of COVID-19. Of the 85 patients, 10 (12%) had a positive RT-PCR test for SARS-CoV2, and 5 patients (6%) had a positive antibody detection test. Three of the 10 RT-PCR-positive patients (30%) underwent seroconversion and had detectable antibodies ≥ 15 days after clinical symptoms. Of the 75 patients with a negative RT-PCR test, 2 patients (2.3%) had detectable SARS-CoV2 IgG antibodies. Among 244 healthcare workers, all were tested with the antibody detection test, including 14 who had previously been tested positive for SARS-CoV2 based on an RT-PCR test. Ten of these 14 RT-PCR positive healthcare workers (71%) underwent seroconversion and had detectable antibodies ≥ 15 days after clinical symptoms. Three of the remaining 230 healthcare workers (1.3%) had detectable antibodies but tested negative for SARS-CoV2 in an RT-PCR test performed at the same time; two of these reported possible COVID-19 symptoms in the preceding weeks.

The data from this analysis indicate that at ≥ 15 days after RT-PCR diagnosis of SARS-CoV2, the rate of seroconversion in patients with cancer was significantly lower compared with healthcare workers (30% vs 71%, P = 0.04). Of note, 6 of the 7 patients who had not undergone seroconversion had received cytotoxic therapy or major surgery in the previous 4 weeks, compared to none of the 5 antibody positive patients (P = 0.003). No patient with confirmed COVID-19 died. The authors conclude that further studies are necessary to confirm if anticancer treatment impacts immune response to SARS-CoV2.

Reference

Solodky ML, et al. Ann Oncol. 2020; April 30 [Epub ahead of print]