Infertile men are nearly three times more likely than men in the general population to develop testicular cancer, new research suggests.
The rate of testicular cancer has more than doubled in many industrialised countries since the mid-1970s, during the same period when infertility rates among men have been climbing, the investigators note in the Archives of Internal Medicine. Whether these two trends are related is unclear.
To explore these issues, researchers at the University of California, San Francisco identified 22 562 men who, with their partners, had sought evaluation at 15 infertility clinics in California between 1967 and 1998. Data from these men were linked to the California Cancer Registry to identify cases of testicular cancer diagnosed between 1988 and 2004. The cancer rate in this group was compared with that in the general population as documented in the Surveillance Epidemiology and End Results registries.
Environment, genetics play a part
Thirty-four cases of testicular cancer were diagnosed at least one year after the start of infertility evaluation. Overall, 4 549 men were infertile and these men were 2.8-times more likely to develop testicular cancer than those without fertility problems.
Lead author Dr Thomas J. Walsh, now at the University of Washington School of Medicine in Seattle, and his colleagues suggest that a common environmental exposure or genetic background may mediate both conditions.
Certain severe types of male infertility have been linked to problems in the body's ability to repair damaged DNA, the authors explain. Faulty DNA repair has also been associated with tumour growth. Thus, some environmental exposure or genetic background that promotes faulty DNA repair could cause both problems at the same time. – (Reuters Health, February 2009)
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