Annual Report 2024
Division of Screening Assessment and Management
Tomio Nakayama, Satoyo Hosono, Ryoko Machii, Noriaki Takahashi, Jin Miyazawa, Takeshi Enomoto, Toshifumi Nanba, Junko Tanaka. Kazuko Matsuda, Nao Ida, Mayuko Tsukakoshi, Akiko Tohtake, Shiho Ito, Jun Kato
Introduction
Our division conducts research on cancer screening assessment (large scale efficacy study and guideline development) and cancer screening management (quality control), as well as training and research projects related to cancer screening, to promote evidence based-cancer screening in Japan.
The Team and What We Do
Our division consists of two teams according to the activities they are in charge of. One is the activity for assessing cancer screening, and the other for Quality Assurance. S. Hosono is the head of the former team, and N. Takahashi and J. Miyazawa manage the prospective studies for evaluation of cancer screening and, A. Tohtake and N. Ida assist in the studies. S. Hosono manages the development of cancer screening guidelines and J. Kato assist with the work. R. Machii is involved in the latter team (quality assurance), and J. Tanaka and K. Matsuda, support the studies and S. Ito assist with the work. M. Tsukakoshi is in charge of E-learning.
Research Activities
Cancer Screening Assessment
1) Studies to evaluate the effectiveness of cancer screening
A randomized controlled trial to evaluate screening for colon cancer using total colonoscopy is currently undergoing follow-up. Cohort study to evaluate screening for cervical cancer using the HPV test and Pap test is undergoing application for cross-referencing with the National Cancer Registry. Randomized controlled trial of lung cancer screening using low-dose CT for non-smokers is also undergoing application for cross-referencing with the National Cancer Registry. Contamination (chest CT scans) rate of controlled arm was low within one-year post registration.
2) Development of cancer screening guidelines and related issues
A colorectal cancer screening guideline 2024 was published in November 2024. A lung cancer screening guideline 2025 draft was opened in January 2025, followed by a public symposium in February 2025.
3) Impact of COVID-19 on cancer screening and cancer care
An evaluation of the impact of COVID-19 on cancer screening showed that screening rates, which had shown a recovery trend in 2021, remained flat in 2022 and had not returned to 2019 levels. Particularly for gastric cancer screening, the shift toward endoscopic screening contributed to a continued gradual decline in gastric X-ray examinations.
4) Development of a reliable method for measuring cancer screening participation rates
A validity study of the National Survey on the Basic Living Conditions conducted in Miyagi Prefecture showed that self-reported participation rates had high sensitivity (96%) but low specificity (30%). The survey's participation rates were considered to be overestimated. Analysis using insurance claims data showed that screening-like procedures covered by health insurance was generally low at 2-8% annually, except for lung cancer screening, which exceeded 20%.
Future Prospects
In the three large-scale efficacy evaluation studies, we will continue follow-up while sequentially releasing study results beyond the primary endpoints. Regarding guidelines, we plan to publish the final version of the lung cancer screening guidelines in 2025. We will strive to complete the manual for cancer screening and cancer care during outbreaks of novel infectious diseases. Using the results of the validity study of the National Survey on the Basic Living Conditions, data on health insurance-based screening-like activities and workplace screening participation rates, we will develop a more accurate formula for estimating screening participation rates.
List of papers published in 2024
Journal
1. Terasawa T, Tadano T, Abe K, Sasaki S, Hosono S, Katayama T, Hoshi K, Nakayama T, Hamashima C. Single-round performance of colorectal cancer screening programs: a network meta-analysis of randomized clinical trials. BMC medicine, 23:110, 2025
2. Takahashi N, Nakao M, Nakayama T, Yamazaki T. Breast Cancer Screening Participation and Internet Search Activity in a Japanese Population: Decade-Long Time-Series Study. JMIR cancer, 11:e64020, 2025
3. Yagi A, Nakagawa S, Ueda Y, Oka E, Ikeda S, Kakuda M, Kobayashi E, Ito Y, Katayama K, Hirai K, Nakayama T, Kimura T. Effectiveness of catch-up and routine program of the 9-valent vaccine on cervical cancer risk reduction in Japan. Cancer science, 115:916-925, 2024
4. Machii R, Takahashi H, Miyazawa J, Nakayama T. Cancer screening in Japan 2 years after the COVID-19 pandemic: Changes in participation, 2017-2021. Preventive medicine reports, 39:102649, 2024
5. Hamashima C, Takahashi H. Cancer screening programs in Japan: Progress and challenges. Journal of medical screening, 31:207-210, 2024