Abstract
Survival of childhood cancer patients has increased remarkably in the last several decades due to therapeutic improvements. Associated with this progress is the emerging need to accurately assess/minimize late effects of cancer therapy in long-term survivors. This paper considers a methodological issue in assessing the risk of second-primary malignant neoplasms, a major late effect of concern, using second-primary female breast cancer as an example. In the assessment of second-primary malignant neoplasm risk, attained age is a critical factor that must be taken into account. Even with follow-up of decades, childhood-cancer survivors are still at relatively young ages for developing adult-onset diseases. Attained ages at follow-up, however, modify cancer risk considerably; for example, in the general population, women aged 40 years have about fivefold increased breast cancer risk compared with women aged 30 years. A failure to account for the natural age-associated increase of risk could alter, or even reverse, analytical conclusions. This problem was studied empirically by both descriptive and regression analyses of two major studies of long-term childhood-cancer survivors, the Childhood Cancer Survivor Study (1975-1999) and the Late Effects Study Group (1955-1994). These showed appreciable differences in the analytical results by not accounting for the natural age-associated increase of risk illustrating a significant impact of this methodological issue on study conclusions.
Original language | English (US) |
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Pages (from-to) | 1108-1113 |
Number of pages | 6 |
Journal | American journal of epidemiology |
Volume | 158 |
Issue number | 11 |
DOIs | |
State | Published - Dec 1 2003 |
Bibliographical note
Funding Information:This work was supported by grant U24-CA-55727 of the National Institutes of Health.
Keywords
- Age distribution
- Age factors
- Cohort studies
- Epidemiologic methods
- Incidence
- Models
- Neoplasms
- Proportional hazards models
- Second primary
- Statistical