THURSDAY, Nov. 29 (HealthDay News) -- Boys whose testes have not descended at birth have an increased risk of developing testicular cancer later in life, a new study says.

The findings raise the question of whether these boys should be regularly monitored to lower their potential risk for testicular cancer, the researchers said.

When testes fail to descend into the scrotum and remain in the abdomen, the condition is called cryptorchidism. It's the most common birth defect in boys and affects about 6 percent of newborn males.

Researchers analyzed 12 studies published between 1980 and 2010 that examined the link between cryptorchidism and testicular cancer. Based on the collective findings of those studies, the researchers calculated that boys with cryptorchidism were nearly three times more likely to develop testicular cancer later in life than those without cryptorchidism.

The findings are published online Nov. 28 in the Archives of Disease in Childhood.

It's not known how certain aspects of cryptorchidism and surgery to correct the disorder may affect the risk of developing testicular cancer, said Robert Carachi, of the department of surgical pediatrics at the Royal Hospital for Sick Children in Glasgow, Scotland, and colleagues.

The most important question raised by the study is whether the increased risk of testicular cancer is significant enough to require regular follow-up for males born with cryptorchidism, the researchers said in a journal news release.

Testicular cancer is the most common cancer in men aged 20 to 45. Worldwide rates of the cancer have increased substantially over the past few decades.

More information

The Nemours Foundation has more about undescended testicles.