Risk of leukemia among survivors of testicular cancer: a population-based study of 42,722 patients.
OBJECTIVE
The aim of this study is to quantify excess absolute risk (EAR) and excess relative risk (ERR) of secondary leukemia among a large population-based group of testicular cancer survivors.


METHODS
We identified 42,722 1-year survivors of testicular cancer within 14 population-based cancer registries in Europe and North America (1943-2002). Poisson regression analysis was used to model EAR (per 100,000 person-years [PY]) and ERR of secondary leukemia. Cumulative risks were calculated using a competing risk model.


RESULTS
Secondary leukemia developed in 89 patients (EAR = 10.8 per 100,000 PY, 95% confidence interval [CI] = 7.6-14.6; ERR = 1.6, 95%CI = 1.0-2.2). Statistically significantly elevated risks were observed for acute myeloid leukemia (AML) (EAR = 7.2, 95%CI = 4.7-10.2) and acute lymphoblastic leukemia (EAR = 1.3, 95%CI = 0.4-2.8). In multivariate analyses, AML risk was higher among patients whose initial management included chemotherapy compared to those receiving radiotherapy alone (p = 0.1). Excess cumulative leukemia risk was approximately 0.23% by 30 years after testicular cancer diagnosis.


CONCLUSIONS
Although ERR of leukemia following testicular cancer is large, EAR and cumulative risk, which are better gauges of the population burden, are small.
Howard
Regan
R
Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA. reganho@mail.nih.gov
Gilbert
Ethel
E
Lynch
Charles F
CF
Hall
Per
P
Storm
Hans
H
Holowaty
Eric
E
Pukkala
Eero
E
Langmark
Froydis
F
Kaijser
Magnus
M
Andersson
Michael
M
Joensuu
Heikki
H
Fossa
Sophie D
SD
Allan
James M
JM
Travis
Lois B
LB
D000328:Adult; D015331:Cohort Studies; D005060:Europe / Q000453:epidemiology; D006801:Humans; D007938:Leukemia / Q000139:chemically induced* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016609:Neoplasms, Second Primary / Q000453:epidemiology*; D009656:North America / Q000453:epidemiology; D012042:Registries; D013736:Testicular Neoplasms / Q000453:epidemiology* / Q000628:therapy