Determinants of enhanced vulnerability to Covid-19 in U.K. cancer patients: Results from the OnCovid study

ABSTRACT

Background: Despite high contagiousness and rapid spread, SARS-Cov-2 has led to heterogeneous outcomes across affected nations. Within Europe, the United Kingdom is the most severely affected country, with a death toll in excess of 100.000 as of February 2021. We aimed to compare the national impact of Covid19 on the risk of death in UK cancer patients versus those in continental Europe (EU). Methods: We performed a retrospective analysis of the OnCovid study database, a European registry of cancer patients consecutively diagnosed with Covid-19 in 27 centres from February 27 to September 10, 2020. We analysed case fatality rates and risk of death at 30 days and 6 months stratified by region of origin (UK versus EU). We compared patient characteristics at baseline, oncological and Covid-19 specific therapy across cohorts and tested these in multivariable Cox regression models to identify predictors of adverse outcome in UK versus EU patients. Results: Compared to EU patients (n = 924), UK patients (n = 468) were characterised by higher case fatality rates (40.38% versus 26.5%, p < 0.0001), higher risk of death at 30 days (hazard ratio, HR 1.64 [95%CI 1.36-1.99]) and 6 months after Covid-19 diagnosis (47.64% versus 33.33%, p < 0.0001, HR 1.59 [95%CI 1.33-1.88]). UK patients were more often males, of older age and more co-morbid than EU counterparts (p < 0.01). Receipt of anti-cancer therapy was lower in UK versus EU patients (p < 0.001). Despite equal proportions of complicated Covid-19, rates of intensive care admission and use of mechanical ventilation, UK cancer patients were less likely to receive anti-Covid-19 therapies including corticosteroids, anti-virals and interleukin-6 antagonists (p < 0.0001). Multivariable analyses adjusted for imbalanced prognostic factors confirmed the UK cohort to be characterised by worse risk of death at 30 days and 6 months, independent of patient's age, gender, tumour stage and status, number of co-morbidities, Covid-19 severity, receipt of anti-cancer and anti-Covid-19 therapy. Rates of permanent cessation of anti-cancer therapy post Covid-19 were similar in UK versus EU. Conclusions: UK cancer patients have been more severely impacted by the unfolding of the Covid-19 pandemic despite societal risk mitigation factors and rapid deferral of anti-cancer therapy. The increased frailty of UK cancer patients highlights high-risk groups that should be prioritised for anti-SARS-Cov-2 vaccination. Continued evaluation of long-term outcomes is warranted.