Scientists have found few risk factors that make a man more likely to develop testicular cancer. Even if a man has one or more risk factors for this disease, it is impossible to know for sure how much that risk factor contributes to developing the cancer. Also, most men with testicular cancer do not have any of the known risk factors.

Undescended testicle: One of the main risk factors for testicular cancer is a condition called cryptorchidism, or undescended testicle(s). About 10% of cases of testicular cancer occur in men with a history of cryptorchidism. Normally, the testicles develop inside the abdomen of the fetus and they descend into the scrotum before birth. In about 3% of boys, however, the testicles do not make it all the way down before the child is born. Sometimes the testicle remains in the abdomen. In other cases, the testicle starts to descend but remains stuck in the groin area.

Most of the time, undescended testicles continue moving down into the scrotum during the child's first year of life. If the testicle has not descended by the time a child turns 1 year old, it probably won't go down on its own. Sometimes a surgical procedure known as orchiopexy is necessary to bring the testicle down into the scrotum

Men with a history of an undescended testicle have an increased risk of testicular cancer. Some experts believe that the risk of testicular cancer may be somewhat higher for men whose testicle stayed in the abdomen as opposed to one that has descended at least partway. Although most cancers develop in the undescended testicle, up to 25% of cases occur in the normally descended testicle. Based on these observations, some doctors conclude that cryptorchidism doesn't actually cause testicular cancer but that there is something else that leads to both testicular cancer and abnormal positioning of one or both testicles.

There is some evidence that orchiopexy done when a child is younger can reduce the risk of his developing certain types of germ cell tumors. The best time to do this surgery to reduce the risk of testicular cancer is not clear. Experts in the United States recommend that orchiopexy be done soon after the child's first birthday for reasons (such as fertility) that are not related to cancer. A recent large study showed that those who had this surgery after the age of 12 were more likely to get testicular cancer than those who had orchiopexy at an earlier age.

Family history: A family history of testicular cancer increases the risk. If a man has the disease, there is an increased risk that one or more of his brothers or sons will also develop it. However, only about 3% of testicular cancer cases are actually found to occur in families, so that most men are unlikely to pass this disorder on to their children.

HIV infection: Some evidence has shown that men infected with the human immunodeficiency virus (HIV), particularly those with AIDS, are at increased risk. No other infections have been shown to increase testicular cancer risk.

Carcinoma in situ: This condition does not produce a mass or cause any symptoms. It isn't clear how often carcinoma in situ (CIS) in the testicles progresses to cancer. In some cases, CIS is found in men who have a testicular biopsy when they have a medical evaluation of infertility or have a testicle removed because of cryptorchidism. Doctors in Europe are more likely than the doctors in this country to look for (and treat) CIS. This may be why the figures for diagnosis and progression to cancer are lower in the United States than in parts of Europe.

Cancer of the other testicle: A history of testicular cancer is another risk factor. About 3% or 4% of men who have been cured of cancer in one testicle will eventually develop cancer in the other testicle.

Age: Ninety percent of testicular cancers occur between the ages of 20 and 54. But this cancer can affect males of any age, including infants and elderly men.

Race and ethnicity: The risk of testicular cancer among white men is about 5 times that of black men and more than 3 times that of Asian-American and American Indian men. The risk for Hispanics/Latinos falls between that of Asians and non-Hispanic/Latino whites. The reason for these differences is not known. Worldwide, the risk of developing this disease is highest among men living in the United States and Europe and lowest among men living in Africa or Asia.

Body size: Some studies have found that the risk of testicular cancer is somewhat higher in tall men but other studies have not.

Last Medical Review: 11/14/2007
Last Revised: 05/14/2009