Difference in net survival using regional and national life tables in Japan

Rina Tanaka; Hiromi Sugiyama; Kumiko Saika; Masashi Matsuzaka; Yoshihiro Sasaki

doi:10.1016/j.canep.2022.102269

Difference in net survival using regional and national life tables in Japan

Cancer Epidemiol. 2022 Dec:81:102269. doi: 10.1016/j.canep.2022.102269. Epub 2022 Sep 28.

Authors

Rina Tanaka¹, Hiromi Sugiyama², Kumiko Saika³, Masashi Matsuzaka⁴, Yoshihiro Sasaki⁵

Affiliations

¹ Department of Medical Informatics, Hirosaki University Graduate School of Medicine, Japan. Electronic address: r-tana@hirosaki-u.ac.jp.
² Department of Epidemiology, Radiation Effects Research Foundation, Japan.
³ Department of Medical Informatics, Hirosaki University Graduate School of Medicine, Japan; Saku Central Hospital Advanced Care Cente, Japan.
⁴ Clinical Research Support Center, Hirosaki University Hospital, Japan; Department of Medical Informatics, Hirosaki University Hospital, Japan.
⁵ Department of Medical Informatics, Hirosaki University Graduate School of Medicine, Japan; Department of Medical Informatics, Hirosaki University Hospital, Japan.

PMID: 36182832
DOI: 10.1016/j.canep.2022.102269

Abstract

Background: National life table is commonly used for estimating cancer net survival. However, the national life table does not reflect condition of people in local area accurately, because there are disparities in cancer mortality rates among the local area in many cases. We investigated magnitude of difference in cancer net survival using the local area in Japan and Japanese life tables.

Methods: We analyzed data from 32,942 cancer patients diagnosed between 2010 and 2012 in Aomori prefecture, Japan. Expected survival rates in Aomori (ESA) and Japan (ESJ) were estimated based on the life table of each area. Five-year net survival rates using ESA and the ESJ were estimated using the Pohar-Perme method.

Results: The difference between net survival rates using the ESA (NSA) and the ESJ (NSJ) were larger than in men (0.3－3.0%) than in women (0.1－0.8%). The largest difference in the net survival rate was observed in prostate cancer patients, because the difference in the expected survival in oldest old men was remarkable.

Conclusion: Two factors affected the difference in the net survival rates resulting from the sensitivity analysis. The difference was larger (1) among older patients or (2) with a longer observation period (person-years).

Keywords: Cancer; Expected survival; Life table; Net survival; Population-based cancer registry.