Predicted long-term impact of COVID-19 pandemic-related care delays on cancer incidence and mortality in Canada

Abstract

Objectives: The COVID-19 pandemic has affected cancer care worldwide. This study aimed to estimate the long-term impacts of the pandemic on cancer incidence and mortality in Canada using a mathematical model. Methods: We developed a stochastic microsimulation model to estimate the cancer care disruptions and its long-term impact on cancer incidence and mortality in Canada. The model reproduces cancer incidence, survival, and epidemiology in Canada, by using cancer incidence, stage at diagnosis and survival data from the Canadian Cancer Registries. We modeled reported declines in cancer diagnoses and treatments recorded in provincial administrative datasets from March 2020-June 2021. We assumed that diagnostic and treatment delays lead to an increased rate of death. Based on the literature, we assumed each 4-week delay in diagnosis and treatment would lead to a 6% to 50% higher rate of cancer death. Results are the median predictions of 10 stochastic simulations. Findings: The model predicts that cancer care disruptions during the COVID-19 pandemic could lead to 21,247 (2.0%) more cancer deaths in Canada in 2020-2030, assuming treatment capacity is recovered to 2019 pre-pandemic levels in 2021. This represents 355,172 life years lost expected due to pandemic-related diagnostic and treatment delays. The highest absolute expected excess cancer mortality was predicted in breast, lung, and colorectal cancers, and in the provinces of Ontario, Québec, and British Columbia. Diagnostic and treatment capacity in 2021 onwards highly influenced the number of predicted cancer deaths over the next decade. Interpretation: Cancer care disruptions during the Covid-19 pandemic could lead to significant life loss; however, most of these could be mitigated by increasing diagnostic and treatment capacity in the post-pandemic era to address the service backlog. Funding: Canadian Institutes of Health Research

Mitigating COVID-19’s impact on missed and delayed cancer diagnoses

“…This model anticipates 21,247 excess cancer deaths over the next 10 years in Canada owing to the pandemic. 15 The impact of COVID-19 on cancer is far reaching: screening backlogs, delayed workup of symptomatic patients and abnormal screening results, and delays in cancer treatment and research, all exacerbated by patient apprehension to be seen in person. It is clear that there is not only a lost cohort of screened patients, but also a subset of missed cancer diagnoses due to delays in patient presentation and assessment, leading to stage migration in those cancers that are diagnosed.…”

Atténuer les répercussions de la COVID-19 sur les diagnostics de cancer manqués ou retardés

“…Ces constatations ont été corroborées dans une deuxième étude par modélisation, ayant comme projections une hausse de 2 % de la mortalité due au cancer au Canada entre 2020 et 2030, avec un pic de 6 % d'excès de mortalité en 2022. Ce modèle anticipe 21,247 décès de plus dus au cancer au cours des 10 prochaines années au Canada en raison de la pandémie 15 .…”

The impact of lag time to cancer diagnosis and treatment on clinical outcomes prior to the COVID-19 pandemic: a scoping review of systematic reviews and meta-analyses

“…Pandemic-induced changes have brought forth the rising concern within the cancer care community as to whether current lag times to diagnosis and treatment that deviate from standardof-care practice will lead to poorer outcomes for cancer patients. With modelling studies forecasting the tolerability of these lag times based on estimated long-term outcomes (13)(14)(15) and . CC-BY-NC 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity.…”