PURPOSE: There are established variations in testicular cancer incidence between ethnic groups within countries.
It is currently unclear whether occurrence of cryptorchidism - a known risk factor for testicular cancer - follows similar patterns. In New Zealand, Māori have unusually higher rates of testicular cancer than European New Zealanders, and therefore we hypothesised that ethnic trends in incidence of cryptorchidism would reflect those of testicular cancer in this context.
MATERIALS AND METHODS: We tested this hypothesis by following-up eligible male neonates born in New Zealand between 2000-2010 (n=318,441) for incidence of orchidopexy-confirmed cryptorchidism and incidence of known risk factors for cryptorchidism (low birth weight, short gestation, and small size for gestational age), using routine maternity, hospitalisation and mortality records. Logistic regression was used to calculate odds ratios for the presence of known risk factors for cryptorchidism by ethnic group. Poisson regression was used to calculate relative risk of cryptorchidism by ethnicity, adjusted for risk factors.
RESULTS: Ethnic patterns of cryptorchidism incidence in New Zealand closely mirrored those observed previously for testicular cancer: Māori had higher rates of cryptorchidism than all other ethnic groups, with Pacific and Asian groups having the lowest rates (incidence Rate Ratios (RR): European/Other referent; Māori adjusted RR 1.2 [95% CI 1.11-1.3]; Pacific 0.89 [0.8-0.99]; Asian 0.68 [0.59-0.79]).
CONCLUSION: Since the principal risk factors for cryptorchidism occur in utero, the results of the current study strengthen the likelihood that the ethnic patterning of testicular cancer is at least partly due to risk factors which occur prior to birth.
Written by:
Gurney J, Sarfati D, Stanley J, Studd R. Are you the author?
Department of Public Health, University of Otago, Wellington, 23a Mein St, Newtown, Wellington 6242, New Zealand.
Reference: J Urol. 2013 May 8. pii: S0022-5347(13)04323-1.
doi: 10.1016/j.juro.2013.05.002
PubMed Abstract
PMID: 23665269
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