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

Abstract

1574 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 Covid-19 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.