Cancer screening in Japan 2 years after the COVID-19 pandemic: Changes in participation, 2017-2021.

Objectives: The impact of the coronavirus disease (COVID-19) pandemic on cancer screening has become a global concern; compared with pre-pandemic levels, the number of individuals who underwent population-based cancer screening in Japan decreased by 10-30% in fiscal year (FY)2020. Therefore, it is important to monitor subsequent changes in the number of participants. Methods: This descriptive study analysed data from a national database to determine changes from 2017 to 2021 in the number of people screened for gastric cancer (upper gastrointestinal [UGI] series or endoscopy), colorectal cancer (faecal immunochemical test), lung cancer (chest X-ray), breast cancer (mammography), and cervical cancer (Pap smear). Results: Compared with the pre-pandemic period (FY 2017-2019), the number of participants in screening programmes in FY2021 decreased maximally for the gastric cancer UGI series (2.8 million to 2.2 million; -23.3 %), followed by those for lung cancer (7.9 million to 7.3 million; -8.2 %), colorectal cancer (8.4 million to 7.8 million; -7.3 %), breast cancer (3.1 million to 3.0 million; -4.5 %), and cervical cancer (4.3 million to 4.1 million; -3.2 %). Conversely, the number of people screened for endoscopic gastric cancer screening increased (1.0 million to 1.2 million; +13.1 %). Conclusions: The number of participants, which decreased sharply immediately after the onset of the COVID-19 pandemic, recovered only slightly in FY2021 and did not return to pre-pandemic levels yet, except for endoscopic gastric cancer screening. Therefore, the impact of this decline in participation in cancer-detection programmes and changes in mortality should be monitored carefully.