An investigation into the seroprevalence of anti-SARS-CoV-2 antibodies revealed that, between the first and second waves of the pandemic, there was a greater increase in seroprevalence among oncology health care workers (HCWs) than among patients with cancer.

These results, observed in patients and HCWs treated or employed at the same cancer center in France, were published in the European Journal of Cancer.

“[T]o the best of our knowledge, no study has been conducted in parallel among both cancer patients and the HCWs caring for them, in the same center, during both waves of the pandemic,” the researchers wrote. “This information is of major potential interest, since the second wave was of greater magnitude in many countries (including France), and occurred after international professional societies of oncology had issued recommendations for the optimal protection of cancer patients.”

Continue Reading

This cross-sectional study was done after the second wave of the COVID-19 pandemic, and results were compared to findings from a prior study done after the first wave.

Participants underwent serological testing for SARS-CoV-2 and completed a questionnaire about their working conditions (502 HCWs) or medical management (507 patients).

Compared with the first wave, seroprevalence was higher after the second wave for both HCWs (15.1% vs 1.8%; P <.001) and patients (4.1% vs 1.7%; P =.038). All HCWs who were seropositive after the first wave remained seropositive after the second wave.

A multivariable analysis showed that seropositivity among HCWs was associated with working in direct patient care (odds ratio [OR], 1.89; P =.0505), having worked in a dedicated COVID-19 unit (OR, 2.68; P =.0036), and contact with a COVID-19-positive person in the workplace (OR, 2.25; P=.0118) or outside of the workplace (OR, 2.55; P=.0297).

For patients with cancer, seropositivity was only significantly associated with contact with someone who tested positive for COVID-19 (OR, 7.31; P<.0001).

The proportion of patients reporting contact with COVID-19-positive individuals was much lower than the proportion of HCWs (7.6% vs 40.7%; P<.0001). Of the HCWs who had been in contact with a COVID-19-positive person, these contacts occurred in the workplace most of the time (84.8%).

“Even though our patients with cancer appear to have taken steps to protect themselves against infection with COVID-19, the increase in seropositivity in this population compared to the end of the first wave underlines the importance of achieving optimal vaccine uptake in these patients, in line with current recommendations, as they are at risk of severe forms of disease,” the researchers wrote. “Our results provide further arguments in favor of preventive health policies for vulnerable populations such as patients with cancer and HCWs in this setting.”

Disclosures: The anti-SARS-CoV-2 immunoassays were funded by Roche Diagnostic France, but the company had no role in the study design or writing of the paper. The study authors declared no conflicts of interest.


Ladoire S, Rederstorff E, Goussot V, et al. Parallel evolution and differences in seroprevalence of SARS-CoV-2 antibody between cancer patients and health care workers in a tertiary cancer center during first and second wave of COVID-19 pandemic: CanSEROcov-II cross sectional study. Eur J Cancer. Published online January 31, 2022. doi:10.1016/j.ejca.2022.01.005