Measuring the impact of COVID-19 on time to treatment for individuals diagnosed with cancer in Manitoba, Canada using an interrupted time series analysis

Abstract

Background

Delays in treatment can lead to increases in cancer morbidity and mortality. There were many concerns that the COVID-19 pandemic led to delays in cancer treatment. Several studies have examined this issue but with serious limitations. We conducted a study that addressed many of these limitations and evaluated changes in first treatment, surgery, systemic therapy, and radiation therapy (RT) during the pandemic for individuals diagnosed with cancer in Manitoba, Canada.

Methods

A population-based, quasi-experimental cross-sectional study with an interrupted time series analysis was used to examine time to first treatment (expressed as treatment rates accounting for the competing risk of death) before (January 2015–September 2019) and after (April 2020–December 2022) the COVID-19 pandemic.

Results

When compared to the counterfactual scenario without COVID-19, first treatments were not received significantly later during the COVID-19 period for any cancer site. Individuals diagnosed with breast, colon, endocrine, or head and neck cancer had their first treatment within 90 days of diagnosis significantly sooner when comparing the COVID-19 period to the counterfactual. When examining type of treatment within one year of diagnosis, individuals diagnosed with breast cancer had surgery significantly later from April to June 2020 and systemic therapy significantly sooner from April 2020 to September 2021. Individuals diagnosed with colon cancer had surgery significantly sooner from April 2020 to June 2021 and individuals diagnosed with rectal cancer had RT significantly later from January to June 2021.

Conclusions

Although significantly impacted by COVID-19, the cancer care system in Manitoba was able to prioritize individuals diagnosed with cancer and modify treatment modalities resulting in no significant delays in first treatment between April 2020 and December 2022.

Policy summary

It will be important to assess long-term survival and if unaltered, the ongoing use of strategies first used in the pandemic might be justified.