Author: By Lynda Williams, Senior medwireNews Reporter
medwireNews: Patients with cancer may be able to mount a similar immunoglobulin (Ig)G antibody response to SARS-CoV-1 infection as healthy individuals, say Italian researchers.
The first interim analysis of the ongoing study at five Italian institutions in Lombardy was reported at the ESMO Virtual Congress 2020 by Antonio Marra, from the University of Milan.
At the time of data cutoff in May 2020, 61 cancer patients and 105 healthcare workers had been enrolled in the trial. Participants had either a confirmed reverse-transcriptase polymerase chain reaction (RT-PCR) nasopharyngeal swab test for SARS-CoV-2, suspicion of infection based on recent contact with a confirmed case or clinical symptoms or imaging results, or were high-risk cancer patients eligible for treatment or surgery.
The presenter explained that cancer patients were significantly older than the healthcare workers (median, 62 vs 41 years) and had more comorbidities, including a significantly higher rate of hypertension (26.2 vs 2.9%) and diabetes (8.2 vs 1.0%). Cancer patients were also significantly more likely to be diagnosed with COVID-19 pneumonitis than the controls (23.0 vs 3.8%).
The majority of the cancer patients had tumours of the breast (55.7%) or lung (13.1%) and 54.1% had metastatic disease; 67.2% had received systemic therapy in the previous 3 months, most commonly endocrine plus targeted treatment (29.5%) or chemotherapy (14.8%), and 1.6% had undergone surgery in this period.
IgG antibodies against SARS-CoV-2 were detected in 83.8% of participants with a positive RT-PCR test result and 8.5% of those with a negative RT-PCR test. And rates of seroconversion were comparable between cancer patients and healthcare workers who had tested positive (88.0 vs 80.0%) or negative (11.0 vs 7.0%) for the virus.
Median time to IgG positivity was also similar in the cancer patients and healthcare workers, at 28.0 versus 23.0 days, respectively.
“Our findings suggest that patients with cancer infected with SARS-CoV-2 have an IgG antibody response comparable to healthy subjects”, Antonio Marra concluded.
However, he cautioned that as approximately 90% of participants had mild-to-moderate COVID-19, the data are “not informative for patients with severe disease” and that the small proportion of patients with recent receipt of chemotherapy means larger studies are required to determine the impact of this modality on COVID-19 seroconversion.
The investigator added that antibody levels were available for just 16.9% of the study population so far.
“We [plan] to follow our patient population and retest for IgG by both quantitative and qualitative assays to measure time and level of immunization as well as antibody titer that is necessary to protect individuals from reinfection”, he said.
Marra A, Generali DG, Zagami P, et al. Anti-SARS-CoV-2 antibody response in patients with cancer and oncology Healthcare workers: A multicenter, prospective study. Ann Oncol 2020; 31 (Suppl 4): S1142–S1215. DOI: 10.1016/annonc/annonc325.
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