Men who are infertile appear to run a greater risk than other males of developing testicular cancer, a new study published this week said.

Testicular germ cell cancer, the most common cancer among young men in developed countries, has risen during the last 30 to 50 years, according to the study in the Archives of Internal Medicine.

The study was carried out by Thomas Walsh who analysed data from some 22,562 men in California who with their partners had sought fertility treatment between 1967 to 1988.

According to his results, some 4,549 men appeared to be infertile. He then compared those figures with California's cancer statistics between 1988 to 2004.

Walsh, who was then at the University of California, San Francisco, and now works at the University of Washington School of Medicine, Seattle, found that 34 men among the 22,562 were diagnosed with testicular cancer less than a year after seeking infertility treatment.

Cross-analysing the results, the study said that compared to men of the same age in the general population, men with male infertility appeared to be 2.8 times more likely to develop testicular cancer.

Ruling out that the infertility itself or its treatments could cause the cancer, the researchers found rather that a genetic fault could explain both the infertility and the development of a testicular cancer tumour. They also cited environmental factors.

The study also noted that sperm quality and male fertility have declined in the last 30 to 50 years in industrialised countries.