Analysis of Time and Age Patterns in Cancer Risk for A-Bomb Survivors

• Published in: Radiation research 1991-05, Vol.126 (2), p.171-186
• Main Authors: Pierce, Donald A., Vaeth, Michael, Preston, Dale L.
• Format: Article
• Language: English
• Subjects: 560151 - Radiation Effects on Animals- Man; A-BOMB SURVIVORS; AGE DEPENDENCE; Age Factors; Analytical estimating; ASIA; Atomic bombs; Biological and medical sciences; BIOLOGICAL EFFECTS; Biological effects of radiation; BIOLOGICAL RADIATION EFFECTS; Cancer; DELAYED RADIATION EFFECTS; DEVELOPED COUNTRIES; DISEASES; Dosage; Dose response relationship; EXPLOSIONS; Female; Follow-Up Studies; Fundamental and applied biological sciences. Psychology; HUMAN POPULATIONS; Humans; Ionizing radiations; JAPAN; Male; Modeling; MORTALITY; Musical intervals; NEOPLASMS; Neoplasms, Radiation-Induced - epidemiology; Neoplasms, Radiation-Induced - etiology; NUCLEAR EXPLOSIONS; Nuclear Warfare; Parametric models; POPULATIONS; RADIATION EFFECTS; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; RADIOINDUCTION; Risk; RISK ASSESSMENT; Standard error; TIME DEPENDENCE; Time Factors; Tissues, organs and organisms biophysics
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3577816

This report has two aims: (1) to describe and analyze the age/time patterns of excess cancer risk in the atomic bomb survivor cohort followed up by the Radiation Effects Research Foundation (RERF), and (2) to describe statistical methods which are used in RERF's analyses of data on mortality and morbidity in the cohort. In contrast to previous analyses of the cohort cancer mortality data, substantial use is made of Japanese national cancer rates for the purpose of investigation of the age/time variations in excess risk. This analysis considers mortality from all cancers except leukemia as a group. Primary attention is given to description in terms of the age-specific excess relative risk, but the importance of appropriate descriptions of the absolute excess risk is also emphasized. When models for the excess risk allow variation with age and time, both constant relative and absolute excess risk models provide similar fits to the data. Previous reports have indicated that for a given age at exposure and sex, the excess age-specific relative risk is remarkably constant throughout the current follow-up period. Statistical analysis here indicates that for those less than about 35 years of age at exposure there is no departure from this pattern, beyond ordinary sampling variation. For those over about 35 years of age at exposure, there is modest evidence of an increasing trend in the excess relative risk, which could plausibly be attributed to effects related to minimal latent period. Some brief consideration is given to modeling the absolute excess risk as the product of an age-at-exposure and time-since-exposure effect. Interpretation of these results, particularly in regard to projections beyond the current follow-up, is discussed.