Abstract
The 2019 coronavirus disease (COVID-19) pandemic has impacted cancer care and the diagnosis of new cases of cancer. We analyzed the impact of the COVID-19 pandemic on patients with cancer by comparing the number of newly diagnosed cases, cancer stage, and time to treatment in 2020 with those in 2018, 2019, and 2021. A retrospective cohort of all cancer cases treated at A.C. Camargo Cancer Center in 2018-2021, identified from the Hospital Cancer Registry, was studied. We analyzed single and multiple primary cancer case and patient characteristics-by year and by clinical stage (early v advanced). Times from diagnosis to treatment were compared according to the most frequent tumor sites between 2020 and the other study years. Between 2018 and 2021, a total of 29,796 new cases were treated at the center including 24,891 with a single tumor and 4,905 with multiple tumors, including nonmelanoma skin cancer. The number of new cases decreased by 25% between 2018 and 2020 and 22% between 2019 and 2020, followed by an increase of about 22% in 2021. Clinical stages differed across years, with the number of new advanced cases decreasing from 17.8% in 2018 to 15.2% in 2020. Diagnoses of advanced-stage for lung and kidney cancer decreased between 2018 and 2020, while the number of thyroid and prostate cancer cases diagnosed in advanced-stages increased from 2019 to 2020. The time from diagnosis to treatment decreased between 2018 and 2020 for breast (55.5 v 48 days), prostate (87 v 64 days), cervical/uterine (78 v 55 days) and oropharyngeal (50 v 28 days) cancers. The COVID-19 pandemic affected the numbers of single and multiple cancers diagnosed in 2020. An increase in the number of advanced-stage cases diagnosed was observed only for thyroid and prostate cancer. This pattern may change in coming years due to the possibility that a significant number of cases went undiagnosed in 2020.