Risk of testicular cancer in subfertile men: case-control study.
OBJECTIVE
To evaluate the association between subfertility in men and the subsequent risk of testicular cancer.


METHODS
Population based case-control study.


METHODS
The Danish population.


METHODS
Cases were identified in the Danish Cancer Registry; controls were randomly selected from the Danish population with the computerised Danish Central Population Register. Men were interviewed by telephone; 514 men with cancer and 720 controls participated.


METHODS
Occurrence of testicular cancer.


RESULTS
A reduced risk of testicular cancer was associated with paternity (relative risk 0.63; 95% confidence interval 0.47 to 0.85). In men who before the diagnosis of testicular cancer had a lower number of children than expected on the basis of their age, the relative risk was 1.98 (1.43 to 2.75). There was no corresponding protective effect associated with a higher number of children than expected. The associations were similar for seminoma and non-seminoma and were not influenced by adjustment for potential confounding factors.


CONCLUSIONS
These data are consistent with the hypothesis that male subfertility and testicular cancer share important aetiological factors.
Møller
H
H
Centre for Research in Health and Social Statistics, Danish National Research Foundation, Sejrogade 11, DK-2100 Copenhagen O, Denmark.
Skakkebaek
N E
NE
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D006801:Humans; D007248:Infertility, Male / Q000150:complications* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D016017:Odds Ratio; D010334:Paternity; D012307:Risk Factors; D012747:Sexual Partners; D013736:Testicular Neoplasms / Q000150:complications* / Q000453:epidemiology