ABSTRACT
IMPORTANCE: The COVID-19 pandemic has put a serious strain on health services, including cancer treatment. OBJECTIVE: This study aimed to investigate the changes in cancer treatment worldwide during the first phase of the SARS-CoV-2 outbreak. DATA SOURCES: Pubmed, Proquest, and Scopus databases were searched comprehensively for articles published between 1 January 2020 and 12 December 2021, in order to perform a systematic review and meta-analysis conducted following the PRISMA statement. STUDY SELECTION: Studies and articles that reported data on the number of or variation in cancer treatments between the pandemic and pre-pandemic periods, comprising oncological surgery, radiotherapy, and systemic therapies, were included. DATA EXTRACTION AND SYNTHESIS: Data were extracted from two pairs of independent reviewers. The weighted average of the percentage variation was calculated between the two periods to assess the change in the number of cancer treatments performed during the pandemic. Stratified analyses were performed by type of treatment, geographic area, time period, study setting, and type of cancer. RESULTS: Among the 47 articles retained, we found an overall reduction of -18.7% (95% CI, -24.1 to -13.3) in the total number of cancer treatments administered during the COVID-19 pandemic compared to the previous periods. Surgical treatment had a larger decrease compared to medical treatment (-33.9% versus -12.6%). For all three types of treatments, we identified a U-shaped temporal trend during the entire period January-October 2020. Significant decreases were also identified for different types of cancer, in particular for skin cancer (-34.7% [95% CI, -46.8 to -22.5]) and for all geographic areas, in particular, Asia (-42.1% [95% CI, -49.6 to -34.7]). CONCLUSIONS AND RELEVANCE: The interruption, delay, and modifications to cancer treatment due to the COVID-19 pandemic are expected to alter the quality of care and patient outcomes.