This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on June 8, 2022.
Each year, more than 9,100 Americans are diagnosed with testicular cancer. Rates of this cancer in the United States and several other nations have been rising over the past few decades, and researchers are still investigating why.
Although the exact causes of testicular cancer are unknown, certain factors may increase an individual's risk of being diagnosed with this condition.
Testicular cancer forms when the DNA in cells in the testicle mutate or change, disabling the functions that control cell growth. Some of these mutated cells may not be caught in time by the immune system, and may instead form a tumor.
Age: Approximately 80 percent of testicular cancers occur in adult men under the age of 44, and more than half occur in men between 20 and 34 years old. The average age at diagnosis is approximately 33.
Race and ethnicity: Caucasian men have a five times greater risk of developing testicular cancer than black men, and a three times greater risk compared with Asian-American or American Indian men. Hispanic/Latino men have a lower risk than Caucasian men but a higher risk than Asian-American men. Testicular cancer also occurs more frequently in the United States and Europe, and less often in Asia or Africa.
Having a brother or father who has had testicular cancer may slightly increase a man's risk of developing the disease, but most people who receive a testicular cancer diagnosis have no family history of the disease.
Cryptorchidism (an undescended testicle): Testicles develop in the abdomen of the fetus and move down into the scrotum before birth. Approximately 3 percent of males may be born with a testicle that has failed to properly descend. A procedure called orchiopexy may be performed to relocate a testicle that has failed to descend normally. Testicular cancer is several times more likely to occur in males with cryptorchordism, and it is more likely to develop in the undescended testicles. Testicular cancer develops in the normally descended testicle in approximately 25 percent of cases.
HIV infection: Some research suggests that infection with the human immunodeficiency virus (HIV) may increase testicular cancer risks, especially in individuals who have developed acquired immune deficiency syndrome (AIDS).
Carcinoma in situ: This is a non-invasive form of testicular cancer that may sometimes, but not always, progress to invasive cancer. Carcinoma in situ generally does not form a mass that can be felt or produce any symptoms. It is most frequently found incidentally in males who have undergone a biopsy of the testicle to evaluate another condition, such as infertility. Experts are divided on whether carcinoma in situ should be treated at the time of diagnosis or watched to see if it progresses.
Previous history of testicular cancer: Approximately 3 percent to 4 percent of men who have had cancer in one testicle will later develop cancer in the other testicle.
Next topic: What are the symptoms of testicular cancer?