Survival of Patients Diagnosed With Cancer During the COVID-19 Pandemic.

[IMPORTANCE] The effects of COVID-19 pandemic-related disruptions on cancer diagnosis in the US have been widely observed, but their impact on short-term survival has not been assessed.

[OBJECTIVE] To examine 1-year cause-specific survival (CSS) rates among patients diagnosed with cancer during 2020 and 2021 using high-quality cancer registry data.

[DESIGN, SETTING, AND PARTICIPANTS] This population-based cohort study of cancer survival between 2015 and 2021 used the Surveillance, Epidemiology, and End Results 21 Registries (SEER-21) database. The population included individuals with an invasive cancer diagnosis and complete follow-up reported to registries included in SEER-21 between January 1, 2015, and December 31, 2021. Data were analyzed from May 13 to May 27, 2025.

[EXPOSURE] COVID-19 pandemic.

[MAIN OUTCOMES AND MEASURES] The primary outcome was 1-year CSS rates by stage at diagnosis for patients diagnosed with cancer in 2020 and 2021 compared with trends in 1-year CSS rates among patients diagnosed between 2015 and 2019. Additional site-specific analyses were performed on common cancer sites identified as having low survival (5-year relative survival <33%) or high incidence and high survival (incidence >20.0 per 100 000 and 5-year relative survival ≥66%).

[RESULTS] A total of 1 008 012 individuals were diagnosed with cancer during the first 2 years of the COVID-19 pandemic, including 473 781 in 2020 (50.1% female; 51.0% diagnosed at ≥65 years; 11.5% Black, 15.8% Hispanic, 64.1% White, and 7.4% other race) and 534 231 in 2021 (50.3% female; 51.9% diagnosed at ≥65 years; 51.9% diagnosed at ≥65 years; 11.7% Black, 16.2% Hispanic, 62.9% White, and 7.9% other race). Compared with prepandemic trends, significant absolute reductions in 1-year CSS rates occurred for early-stage diagnoses in 2020 (-0.44 [95% CI, -0.54 to -0.34] percentage points) and 2021 (-0.27 [95% CI, -0.37 to -0.16] percentage points) and late-stage diagnoses in 2020 (-1.34 [95% CI, -1.75 to -0.93] percentage points) and 2021 (-1.20 [95% CI, -1.69 to -0.71] percentage points). Survival reductions resulted in an estimated 17 390 more cancer-related deaths (13.1%) within 1 year of diagnosis than expected during the first 2 years of the COVID-19 pandemic. Absolute survival reductions greater than 1.00 percentage point occurred in both years for late-stage diagnoses among individuals of other non-Hispanic race and ethnicity (ie, American Indian and Alaska Native, Asian or Pacific Islander, or unknown race) and individuals aged 65 years or older. Significant site-specific survival reductions also existed in both 2020 and 2021, respectively, for early-stage diagnoses of esophageal cancer (-3.89 and -3.67 percentage points) and colorectal cancer (-1.08 and -0.78 percentage points) and late-stage diagnoses of prostate cancer (-0.64 and -0.77 percentage points).

[CONCLUSIONS AND RELEVANCE] This cohort study found that individuals diagnosed with cancer in 2020 and 2021 experienced worse short-term survival than those diagnosed between 2015 and 2019, suggesting substantial harms associated with cancer care disruptions during the first 2 years of the COVID-19 pandemic.