RESEARCHERS have discovered a method of detecting the early signs of testicular cancer before it starts to spread.
A team in Copenhagen discovered that the disease could be diagnosed early by testing semen samples.
They hope their findings will lead to the development of a simple screening test for men at risk.
Testicular cancer affects around 2000 men in the UK each year, and more than 90 per cent of cases are curable, especially if caught early enough.
Sports stars like former Celtic player Alan Stubbs and three-time winner of the Tour de France Lance Armstrong have beaten the disease. But it can prove difficult to detect before it begins to spread, meaning surgery is usually used in conjunction with chemotherapy or radiotherapy which may cause infertility.
The researchers, writing in the journal Human Reproduction, said they had focused on looking for pre-invasive testicular carcinoma in situ (CIS) in semen samples.
Researchers found the TFAP2C gene, which produces a protein called AP-2gamma, was expressed in CIS and therefore provided a marker for detecting cancer.
The team analysed semen samples from a group of patients with testicular cancer, men with other types of cancer and infertility problems and a group of apparently healthy young men.
Dr Hoei-Hansen said: "When we were evaluating the first series of semen samples we detected AP-2gamma positive cells in a sample from one of the healthy controls.
"He was a 23-year-old man who was having a routine semen analysis because he and his partner had been trying for 18 months to have a baby. Further clinical evaluation revealed CIS in his left testicle."
The man had the testicle removed in surgery but did not need chemotherapy or radiotherapy. He and his partner went on to conceive naturally and are awaiting their first child, the researchers said.