Boys whose testicles do not come down into the scrotum are 3 times more likely to have testicular cancer later in life. Before birth, the testicles are formed inside the body. Shortly before birth, they normally move down into the scrotum. In 3% to 4% of full-term boys and about 33% of premature boys, this does not happen. One or both testicles remain in the body. This is called cryptoorchidism. Researchers looked at 12 published studies of cryptoorchidism and testicular cancer risk. The studies included a total of more than 2 million boys. The research showed an increased risk for testicular cancer. The study was published in the Archives of Disease in Childhood. HealthDay News wrote about it November 29.

By Henry H. Bernstein, D.O.
Harvard Medical School

What Is the Doctor's Reaction?

There is so much that happens as a fetus grows into a boy inside the womb. For example, the testicles begin to form inside his belly. Shortly before birth, the testicles move down into the sack that holds them. It's called the scrotum.

Sometimes, one or both testicles may not come all the way down into the sack. When this occurs, it is called cryptorchidism. It also is known as undescended testicles.

Cryptorchidism is the most common genital problem found in boys. It happens in 3% to 4% of full-term baby boys. It is even more common in premature boys: it affects about 33% of them. That's because there is less time for the testicles to come down into the scrotum.

Previous studies have shown that boys born with cryptorchidism are more likely to develop testicular cancer as they get older. How much of an increased risk is not known. A recent article published in the journal Archives of Disease in Childhood studied the link between cryptorchidism and testicular cancer. The researchers looked more closely at a group of 12 earlier studies. The results from these studies:

• Were published between 1980 and 2010
• Included more than 2 million boys
• Included hundreds of males found to develop testicular cancer
• Followed the boys for a total of 58 million person-years

The researchers concluded that boys born with cryptorchidism are 3 times more likely to end up with testicular cancer than boys born without cryptorchidism. Preventing cancer of any kind is always the ideal. In this case, knowing where both testicles are right from birth is most important. What is the best way to check (and how often to do it) in all males is not clear.

What Changes Can I Make Now?

When your son is born, you need to know whether both testicles are in the scrotum. Cryptorchidism is usually diagnosed by a physical exam at birth or at checkups during infancy.

If one or both testicles are not found on exams in the nursery, your son's doctor should follow the problem closely. The testicles must not stay in the belly too long. We now know this can result in a 3-fold higher risk of testicular cancer.

Be sure both testicles come all the way down into the scrotum by 6 to 12 months of age. In many cases, cryptochidism will correct itself during the baby’s first year of life.

If one or both testicles have not come down into the scrotum by age 1, a pediatric urologist should check the infant. This is a specialist who treats problems of the genitals and urinary system.

When the pediatric urologist confirms cryptorchidism, a treatment plan will be discussed. This usually involves finding the missing testicle and surgically moving to the scrotum. It is important that cryptorchidism be treated because:

• A testicle in the belly is surrounded by a higher body temperature than a testicle in the scrotum. The higher temperature harms the normal development of the testicle. This can lead to infertility problems.


• The undescended testicle is more likely to form a tumor than one in the scrotum.


• The undescended testicle is more likely to be injured or twist on itself (testicular torsion).


• Having an empty scrotum on one or both sides may cause a boy to be embarrassed and worried.

What Can I Expect Looking to the Future?

Testicular cancer is on the rise around the world. It is one of the most common cancers in males. Experts will continue to look for ways to lower the risk.

Researchers will keep studying how cryptorchidism and testicular cancer are linked. For example, work must continue to find the reason for cryptorchidism, which is not known at this time. The above study also raised a number of questions that still need to be answered:

• Are certain types of cryptorchidism (for example, one side versus the other side versus both sides) more closely linked with cancer?
• Are boys born with cryptorchidism at a high enough risk that they should be regularly screened for testicular cancer?
• Does having surgery to fix cryptorchidism reduce a boy’s risk for cancer?