Were cancer patients worse off than the general population during the COVID-19 pandemic? A population-based study from Norway, Denmark and Iceland during the pre-vaccination era

• Published in: The Lancet Regional Health - Europe
• Main Authors: Johansson, Anna L.V., Skog, Anna, Johannesen, Tom Børge, Myklebust, Tor Åge, Skovlund, Charlotte Wessel, Mørch, Lina Steinrud, Friis, Søren, Gamborg, Mads, Kristiansen, Marnar Fríðheim, Pettersson, David, Ólafsdóttir, Elínborg J., Birgisson, Helgi, Palsson, Runolfur, Eythorsson, Elias, Irenaeus, Sandra, Lambe, Mats, Ursin, Giske
• Format: Text
• Language: English
• Published: Elsevier 2023
• Subjects: Articles; Norway; Iceland
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC10398597/; https://doi.org/10.1016/j.lanepe.2023.100680

BACKGROUND: In a population-based setting, we investigated the risks of testing positive for SARS-CoV-2 and developing severe COVID-19 outcomes among cancer patients compared with the general population. METHODS: In nationwide cohorts, we identified all individuals in Norway, Denmark and Iceland who tested positive for SARS-CoV-2 or had a severe COVID-19 outcome (hospitalisation, intensive care, and death) from March until December 2020, using data from national health registries. We estimated standardised incidence ratios (SIRs) with 95% confidence intervals (CIs) comparing cancer patients with the general population. FINDINGS: During the first wave of the pandemic, cancer patients in Norway and Denmark had higher risks of testing SARS-CoV-2 positive compared to the general population. Throughout 2020, recently treated cancer patients were more likely to test SARS-CoV-2 positive. In Iceland, cancer patients experienced no increased risk of testing positive. The risk of COVID-19-related hospitalisation was higher among cancer patients diagnosed within one year of hospitalisation (Norway: SIR = 2.43, 95% CI 1.89–3.09; Denmark: 2.23, 1.96–2.54) and within five years (Norway: 1.58, 1.35–1.83; Denmark: 1.54, 1.42–1.66). Risks were higher in recently treated cancer patients and in those diagnosed with haematologic malignancies, colorectal or lung cancer. Risks of COVID-19-related intensive care and death were higher among cancer patients. INTERPRETATION: Cancer patients were at increased risk of testing positive for SARS-CoV-2 during the first pandemic wave when testing availability was limited, while relative risks of severe COVID-19 outcomes remained increased in cancer patients throughout 2020. Recent cancer treatment and haematologic malignancy were the strongest risk factors. FUNDING: Nordic Cancer Union.