Does COVID‐19 pandemic impact cancer outcomes in metastatic setting? A comparative cohort study among metastatic patients treated at day care hospital

INTRODUCTION: COVID‐19 outbreak rapidly spread since early 2020 leading to the implementation of nationwide lockdowns. To cope with this sudden change, management guidelines were quickly published to adapt oncological care, with potential impact on cancer outcomes. METHODS: We conducted a retrospective comparative cohort study to assess the impact of the COVID‐19 outbreak in 2020 on cancer outcomes in metastatic patients. Two cohorts of metastatic patients receiving intravenous (iv) therapy in a French oncological day care hospital were assessed: a 2020 cohort during the first French lockdown, and a 2018 historical cohort before the COVID‐19 pandemic. We performed a propensity score analysis to match patients from the two cohorts. After one‐year follow‐up, we compared progression‐free survival (PFS) and overall survival (OS) between cohorts. Adaptations of medical oncological treatments in 2020 were also analysed. RESULTS: The 376 patients of the 2020 cohort were matched with 376 of the 2018 cohort. No SARS‐CoV‐2 infection was observed in the 2020 cohort. The adjusted PFS was significantly shorter in 2020 compared to 2018 (HR = 1.23; 95% CI: 1.03–1.46), as well as among patients without treatment adaptation compared to matched patients of the 2018 cohort (HR = 1.33; 95% CI: 1.10–1.61). We did not observe any significant difference of PFS among the group with treatment adaptations. OS was not significantly different. CONCLUSION: Metastatic cancer patients treated during the first lockdown had a higher risk of disease progression 1 year after COVID‐19 outbreak. However, oncological treatment adaptations or SARS‐CoV‐2 infections do not explain these results. A longer follow‐up is needed to observe the impact on OS.