There is no way to prevent most cases of testicular cancer.
Men who had an undescended testicle at birth should be monitored regularly for early signs of cancer. Most pediatricians recommend surgery to lower an undescended testicle into the scrotum at a very early age. If the testicle did not even begin its descent into the scrotum, some pediatricians recommend removing it. These "abdominal testes" are more likely to become cancerous over time.