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# Cancer in Japanese adults aged 85 and over rose more than four-fold between 1995 and 2020
- URL: https://www.coios.me/cancer-in-japanese-adults-aged-85-and-over-rose-more-than/
- Published: 2026-10-16T13:10:14.000Z
- Updated: 2026-10-17T08:14:41.000Z
- Description: Registry data show cancer cases in the oldest-old rising 5.9% a year, reaching 15.7% of all Japanese cases by 2020.
- Author: Daniel Ryan
- Tags: Health today, Cancer, Japan, #peer-reviewed, #new, #item, #source-2026-10, #score-70

The study examined cancer incidence, mortality, stage and treatment in Japanese adults aged 85 and over. It used national and prefectural cancer registry data from 1995 to 2020, comparing young-old adults aged 65-84\. Cases in the oldest-old rose more than four-fold, average annual percent change +5.9% (CI 5.4-6.3). This growth was faster than in the overall and young-old populations, reaching 15.7% of all cases in 2020\. The oldest-old had more skin and gallbladder/bile duct cancers, and more advanced or unstaged disease. Aggressive treatment was less common than in young-old patients at similar stage, in a descriptive registry analysis.

*Why it is interesting: Japan has the largest share of people aged 85 and over. Stage at diagnosis and treatment intensity both differ at these ages.*

Source

[International Journal of Cancer, 15 October 2026](https://doi.org/10.1002/ijc.70797?ref=coios.me)

Paper

Cancer in the Oldest‐Old in Super‐Aging Japan: Trends and Characteristics From National Registry Data

Authors

Tanaka S, Tanaka H, Katanoda K

DOI

10.1002/ijc.70797

Type

Peer-reviewed article

Design

Population-based national and prefectural cancer registry analysis, Japan, 1995-2020, ages 85+ compared with 65-84

Verdict

New finding

Driver

[Cancer](https://www.coios.me/d-cancer/)

Free full text

[Free to read at the publisher](https://doi.org/10.1002/ijc.70797?ref=coios.me)

Abstract — the authors' own words, CC BY

ABSTRACT

Globally, Japan has the largest proportion of individuals aged ≥ 85 years. However, epidemiological studies on cancer in this age group are limited. This study aimed to investigate cancer trends and characteristics among the oldest‐old adults (aged ≥ 85 years) in Japan, using population‐based national and prefectural cancer registry data on incidence, mortality, trends, stage, and treatment patterns, and compared them with those of young‐old adults (aged 65–84 years). From 1995 to 2020, the number of cancer cases among the oldest‐old increased more than four‐fold, with a significant average annual percent change of +5.9% (confidence interval: 5.4–6.3), surpassing growth in both the overall and young‐old populations, and accounting for 15.7% of all cases in 2020\. The oldest‐old showed higher proportions of skin and gallbladder/bile duct cancers, and rising proportions of breast and prostate cancers. The group was more likely to be diagnosed at unstaged or advanced stages of cancer. Aggressive treatment was less commonly administered to this group, even when the stage at diagnosis was similar to that in the younger‐old patients. These findings highlight distinct epidemiological and clinical cancer trends in the oldest‐old. Since cancer incidence among the oldest‐old will likely continue to rise, targeted healthcare and policy interventions that consider the impact of this age group at both individual and societal levels are urgently needed. To address the needs of an aging population, reconsideration of prevention, detection, and management, including guidelines and specialist availability, is suggested. Moreover, Japan must consider further cancer research in this rapidly increasing population.