What is it?
Testicular cancer is an abnormal, uncontrolled growth of cells that forms a tumour in one or both testicles. Men have two testicles (testes, gonads) that are located in the scrotum, the pouch of loose skin below the base of the penis. The testicles are responsible for producing sperm and male hormones (mainly testosterone) that regulate reproductive organ development.
Testicular cancer is the most common cancer in males between 20 and 40 years of age. About 2,000 men are diagnosed with the condition in the UK each year. It is several times more common in white males than in men of African, Hispanic, or Asian descent, although the cause for this additional risk is not known. Other factors that can increase risk include undescended testicles (cryptorchidism) if not corrected before the age of 11, abnormal development of the testes (gonadal dysgenesis), inflammation of the testes (orchitis) which can rarely occur after mumps, genetic disorder called Klinefelter’s syndrome, and a family history of testicular cancer. Individuals who handle pesticides, leather workers, miners, oil well workers, and HIV positive persons also appear to be at higher risk.
Germ cells, which normally develop into sperm, account for about 94% of testicular tumours. These tumours are devided into two groups, seminomas (40%) and non-seminomas (60%). Seminomas occur most ofter in men in their thirties. They tend to grow very slowly and usually do not spread (metastasize). Non-seminomas mainly affect men in their twenties and tend to grow and spread more quickly.
About 4-5% of all testicular tumours (20% children) form in the cells that produce hormones. These tumours may secrete oestradiol, a female sex hormone which can then cause breast growth (gynaecomastia).