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Overview of latest SEER data and the impact of COVID on cancer incidence trends and reporting
(April 20, 2023)

The November 2022 SEER data submission includes new cancer cases diagnosed in 2020, the first year of the COVID-19 pandemic. In 2020, the highly publicized impact of COVID on health services and the consequential delays and reductions in cancer screening and diagnosis led to a decline in the 2020 incidence rates for most cancer sites.

Because 2020 was a temporary, anomalous year caused by the pandemic, it can bias estimates such as cancer incidence trends that are of substantive interest. To address the bias, SEER made some changes in the reporting of cancer statistics this year.

  • The 2020 incidence data is included all SEER incidence databases and in most cancer statistics in SEER*Explorer, Stat Facts, and other web-based reports.
  • The 2020 incidence data is excluded from two cancer statistics: estimation of Joinpoint trends and risks of developing cancer (DevCan).

The 2020 incidence cases are available in the SEER Research Data for analysis through SEER*Stat.

Exclusion of 2020 Incidence Data from Joinpoint Trends

The joinpoint regression model for the analysis of trends was not designed to accommodate a one-year anomaly in data nor to estimate a change in one single calendar year. Inclusion of the 2020 incidence can influence the location of joinpoints, the value of the trend measure (annual percent change), and provide a poor fit of the model and larger confidence intervals, challenging the interpretation of estimate’s  association with risk factors and efforts in prevention and early detection.

The joinpoint models used by SEER to report trends were fitted to the November 2022 data submission using rates through 2019. The 2020 incidence rates are included in statistical reports and displayed in graphs but are not used in the joinpoint model.  Refer to an example from SEER*Explorer for Recent Trends in SEER Incidence Rate for All Cancer Sites, 2000-2020.

Exclusion of 2020 Incidence Data from Risks of Developing Cancer

For the November 2022 data submission, SEER uses 2017-2019 incidence rates instead of 2018-2020 to compute the risks of being diagnosed with cancer. Including 2020 in the estimates would correspond to someone living their entire lifetime under the pandemic-induced 2018-2020 incidence rates. Estimates of the risk of being diagnosed with cancer are calculated by applying cross-sectional, age-specific incidence rates and death rates to a hypothetical cohort of 10,000,000 live births. The probabilities of developing the specified cancer and dying of other causes (before developing the specified cancer) are calculated using multiple decrement life tables implemented in DevCan. The methods use the most recent 3-years to gain stability. For this reason, we have chosen to use 2017-2019 rather than 2018 through 2020 to compute the risks of being diagnosed with cancer.

Decline of 2020 Cancer Incidence Rates Relative to 2019 Rates

To measure the impact of COVID on 2020 incidence, we provide the table below that reports the decline of 2020 cancer incidence rates relative to 2019 rates for 10 major cancer sites using the percent change (PC) of the rates in 2020 compared to 2019, i.e., the difference in the rates in 2020 and 2019 divided by the rate in 2019. The list will be expanded in the future.

Percent change1 in age-standardized, delay-adjusted2 incidence rates from 2019 to 2020 by Cancer Site and Sex, using the November 2022 data submission.
Cancer Site 2019 Delay-Adjusted Rate3,4 2020 Delay-Adjusted Rate3 Percent Change (PC) 95% Confidence Interval
Lower, Upper
All sites 459.5 416.9 -9.26% -9.56%, -8.97%
Breast (Females) 134.4 121.5 -9.60% -10.35%, -8.85%
Colorectal 37.6 33.6 -10.69% -11.69%, -9.68%
Kidney and Renal Pelvis 18.2 16.5 -9.52% -10.97%, -8.04%
Leukemia 15.1 14.3 -5.66% -7.37%,  -3.92%
Lung 50.6 44.6 -11.88% -12.71%, -11.04%
Melanoma of the Skin 22.5 19.1 -15.17% -16.43%, -13.90%
Non-Hodgkin Lymphoma 19.3 17.8 -7.76% -9.20%, -6.31%
Prostate 124.4 110.5 -11.20% -11.99%, -10.41%
Urinary Bladder 18.5 17.3 -6.23% -7.68%, -4.75%
  1. Estimates of PC=100 x [rate (2020)/rate (2019)-1] where ratio= rate (2020)/rate (2019) and its confidence intervals are calculated in SEER*Stat. The lower and upper limits of the confidence interval for PC are calculated as (Lower CI – 1) x 100 and (Upper CI – 1) x 100, respectively.
  2. Incidence rates were delay-adjusted using the November 2022 submission delay adjustment factors.
  3. Rates are per 100,000 population.
  4. Rates updated with most recent delay factors on 05/17/2023.

For More Information

Learn more about the impact of COVID on cancer incidence trends in the following article:

Mariotto AB, Feuer EJ, Howlader N, Chen HS, Negoita S, Cronin KA. Interpreting cancer incidence trends: challenges due to the COVID-19 pandemic. J Natl Cancer Inst. 2023 Sep 7;115(9):1109-1111. doi: 10.1093/jnci/djad086. https://doi.org/10.1093/jnci/djad086External Web Site Policy