Results from an analysis involving both cancer patients and healthcare workers at Centre Léon Bérard in Lyon, France, showed that patients with cancer had a significantly lower detection rate of SARS-COV2 antibodies 15 days or later after COVID-19 symptoms and RT-PCR-positive test than healthcare workers.
The team of researchers led by Prof. Jean-Yves Blay reported the results on30 April 2020 in the Annals of Oncology.
The analysis also showed that 5 of 85 patients with cancer (5.9%) and 13 of 244 healthcare workers (5.4%) had detectable antibodies against COVID-19. However, the antibodies were more often undetectable in patients who received anticancer treatment in the month prior to testing.
At the time of active infection, COVID-19 is diagnosed by detection of the SARS-COV2 virus in nasopharyngeal samples by RT-PCR. Most of infected patients develop antibodies against SARS-COV2 proteins.
The Centre Léon Bérard study team retrospectively analyzed patients with cancer who presented with suspected COVID-19 from 1 March 2020 to 16 April 2020 and who were enrolled in Oncovid-19 clinical trial approved by an Institutional Review Board on 12 March 2020, and a series of healthcare workers who underwent voluntary testing in their centre.
In total, 85 patients with cancer were tested both with SARS-nCoV2 RT-PCR on nasopharyngeal samples and a point-of-care antibody diagnostic test called Toda Coronadiag® developed by TODA Pharma based in Strasbourg, France. Coronadiag® is a rapid lateral flow immunoassay which provides results in 10 minutes by using a finger-pricked blood sample. Coronadiag® was performed 15 days or more after RT-PCR-positive test or COVID-19 symptoms. Coronadiag® test was performed in 244 nurses and doctors. SARS-CoV2 RT-PCR was found positive previously in 14 healthcare workers who presented with clinical symptoms and it was performed in the 3 healthcare workers who were tested positive for SARS-COV2 antibodies.
In total, 10 of 85 patients with cancer (12%) had documented SARS-CoV2 by RT-PCR, and 5 patients (6%) had a positive antibody detection test. Three of the 10 patients (30%) with infection confirmed by RT-PCR had detectable antibodies 15 days after the clinical start of the infection. Two of the 75 remaining patients with cancer (2.3%) screened negative by RT-PCR had detectable SARS-COV2 IgG.
All 244 healthcare workers were tested with the Coronadiag® test, including 14 with COVID-19 confirmed by RT-PCR. Ten of these 14 healthcare workers (71%) with RT-PCR documented infection had detectable antibodies 15 days or later after clinical symptoms. Three of the remaining 230 healthcare workers (1.3%) had detectable antibodies, but at the same time had a negative RT-PCR test. Two of them reported symptoms suspected for COVID-19 in the previous weeks.
The study team found that the rate of seroconversion 15 days after SARS-COV2 infection confirmed by RT-PCR was significantly lower in patients with cancer than in healthcare workers (30% vs 71%, p = 0.04).
Furthermore, the study team reported that 6 of the 7 serodiagnostic-negative patients with cancer received cytotoxic therapy or underwent major surgical intervention in the previous 4 weeks, compared to none of the 5 remaining patients (p = 0.003). None of these patients died.
The authors concluded that in their series, patients with cancer had a significantly lower detection rate of SARS-COV2 antibodies 15 days or later after symptoms of COVID-19 and RT-PCR-positive test. Antibodies were more often undetectable in patients who received anticancer treatment in the month prior to testing. They emphasised that additional studies are needed to confirm whether immune response to the virus is influenced by recent treatment for cancer.
The study was funded by NetSARC and RREPS, RESOS and LYRICAN, Association DAM’s, Eurosarc, la Fondation ARC, Infosarcome, InterSARC, LabEx DEvweCAN, PIA Institut Convergence Francois Rabelais PLAsCAN, Ligue de L’Ain contre le Cancer, La Ligue contre le Cancer, and EURACAN.
Solodky ML, Galvez C, Russias B, et al. Lower detection rates of SARS-COV2 antibodies in cancer patients vs healthcare workers after symptomatic COVID-19. Annals of Oncology; Published online 30 April 2020. DOI: https://doi.org/10.1016/j.annonc.2020.04.475