# COVID-19 and Cancer Detection in Russia

## TL;DR

The study found that fewer cancer cases were diagnosed during the pandemic in Russia, but deaths stayed the same, suggesting overdiagnosis from mass testing.

## Contribution

The paper provides evidence that reduced cancer screening during the pandemic did not increase mortality, supporting the idea of overdiagnosis in certain cancers.

## Key findings

- Fewer new cancer cases were diagnosed in 2020 during the pandemic, but mortality remained unchanged.
- Cancer detection rates returned to pre-pandemic levels by 2022.
- The data supports the hypothesis that mass testing leads to overdiagnosis of breast, prostate, renal, and thyroid cancers.

## Abstract

The COVID-19 pandemic caused a noticeable decrease in the number of cases of breast, prostate, renal, and thyroid cancers newly diagnosed in 2020 in the Russian Federation. There was no visible impact on mortality from these diseases. Mortality did not change during the pandemic and has remained at pre-pandemic levels until now. The detection rate returned to pre-pandemic levels during 2021–2022. One could speculate that the decrease in the number of newly diagnosed cases is due to cancer tests skipped during the lockdown. This is further evidence of the overdiagnosis of breast, prostate, renal, and thyroid cancers, which is linked to the mass testing of healthy populations.

Overdiagnosis, associated with mass testing in healthy populations, is a significant issue for breast, prostate, renal, and thyroid cancers. During the lockdowns caused by the COVID-19 pandemic, the intensity of cancer screening was expected to go down. In this study, we analyzed the impact of the expected reduction in screening intensity on morbidity and mortality from certain malignancies. Cumulative data from the Russian National Cancer Registry available from 2000 to 2022 were analyzed. It was noted that there has been no noticeable effect of the COVID-19 lockdowns on mortality rates from breast, prostate, renal, or thyroid cancers. At the same time, the detectable incidence decreased markedly in 2020 at the time of the lockdowns and then returned to pre-pandemic levels in 2022. At the moment, there is no sufficient reason to believe that skipping screening tests in 2020 could have any impact on breast, prostate, renal, or thyroid cancer mortality two years later (2022). The data presented further confirm that the overdiagnosis of these types of malignancies is caused by widespread screening among a generally healthy population.