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.

Japanese cancer screening programs during the COVID-19 pandemic: Changes in participation between 2017-2020.

BACKGROUND: The impact of the coronavirus disease 2019 (COVID-19) pandemic on cancer screening participation is a global concern. A national database of screening performance is available in Japan for population-based cancer screening, estimated to cover approximately half of all cancer screenings. METHODS: Utilizing the fiscal year (FY) 2017-2020 national database, the number of participants in screenings for gastric cancer (upper gastrointestinal [UGI] series or endoscopy), colorectal cancer (fecal occult blood test), lung cancer (chest X-ray), breast cancer (mammography), and cervical cancer (Pap smear) were identified. The percent change in the number of participants was calculated. RESULTS: Compared with the pre-pandemic period (FY 2017-2019), in percentage terms FY 2020 recorded the largest decline in gastric cancer UGI series (2.82 million to 1.91 million, percent change was -32.2 %), followed by screening for breast cancer (3.10 million to 2.57 million, percent change was -17.2 %), lung cancer (7.92 million to 6.59 million, percent change was -16.7 %), colorectal cancer (8.42 million to 7.30 million, percent change was -13.4 %), cervical cancer (4.26 million to 3.77 million, percent change was -11.6 %), and gastric cancer via endoscopy (1.02 million to 0.93 million, percent change was -9.0 %). CONCLUSION: The number of participants in population-based screenings in Japan decreased by approximately 10-30 % during the pandemic. The impact of these declines on cancer detection or mortality should be carefully monitored.

The Prefectural Participation Rates of Lung Cancer Screening Had a Negative Correlation with the Lung Cancer Mortality Rates

Background: The participation rate is one of the most important indexes in the cancer screening. Historically in Japan, each local government has developed their own equations to calculate the subjects for population-based screening, which were different from each other, and therefore the participation rates of screening were not comparable. Recently, local governments were ordered to use the standardized equation in reporting data, which made it possible to compare the participation rates of cancer screening nationwide for the first time. We therefore investigated the correlation between the prefectural lung cancer mortality and several indicators of lung cancer screening. Methods: The prefectural participation rates of lung, gastric and colonic cancer screening, test positive rates, attendance rates for further examination, lung cancer detection rates and positive predictive values of lung cancer screening were collected from "Cancer Registration and Statistics" of the National Cancer Research Center website. The age-adjusted lung, gastric and colonic cancer mortality rates, smoking rates were also collected. The EZR software program was used for statistical analyses. Results: The participation rates of lung cancer screening had a strong positive correlation with the participation rates of gastric/colonic cancer screening (P<0.001). The prefectural lung cancer mortality rates had a moderate to weak negative correlation with the participation rates of lung cancer screening (P=0.009). A little correlation was noted between other quality assurance indicators of lung cancer screening and lung cancer mortality rates. Conclusion: These results suggested that participating in lung cancer screening might help reduce lung cancer mortality rates in some extent.

Trends in the quality assurance process indicators for Japanese colorectal cancer screening during 2003-13.

BACKGROUND: Recently, the importance of quality assurance (QA) for cancer screening has gained increasing attention in Japan. This study aimed to evaluate QA process indicators for population-based colorectal cancer screening during 2003-13. METHODS: A national cancer screening database was used to evaluate the following process indicators: the positivity rate, diagnostic follow-up rate, unidentified results rate, non-compliance with diagnostic follow-up rate, cancer detection rate and positive predictive value (PPV). RESULTS: The positivity rate remained constant at 6.5% until 2011, and then increased slightly thereafter. During 2003-13, the cancer detection rate increased from 0.15% to 0.21%, and the PPV increased from 2.2% to 3.1%. Although the diagnostic follow-up rate increased from 58% to 67%, the non-compliance with diagnostic follow-up rate decreased from 24% to 16% and the unidentified results rate decreased from 18% to 17%. CONCLUSIONS: During the study period, the QA process indicators for colorectal cancer screening in Japan generally improved. However, the recent increase in the positivity rate requires careful observation. Innovative solutions are needed to increase the diagnostic follow-up rate.