The testicles are located under the penis in a pouch called the scrotum. They produce and store sperm, and they are also the main source of the male hormone testosterone. This hormone controls the development of the male reproductive organs and other male characteristics, such as body and facial hair.
Testicular cancer occurs when cells in one or both testicles begin to grow in a disorderly fashion. There are good treatments for this type of cancer, and it can usually be cured if caught early.
Testicular cancer is a fairly rare disease. It accounts for only 1 percent of all cancer in men. Still, it is the most common cancer in young men ages 15 to 35.
What are the types of testicular cancer?
More than 9 out of 10 testicular cancers start in the germ cells, which are the sperm-producing cells in the testicles. There are 2 main types of germ cell cancers:
- Seminomas are slow-growing and tend to stay localized in the testicle for long periods. They often respond better to treatment than nonseminomas. Men with seminomas are often in their 30s or 40s.
- Nonseminomas usually grow and spread faster than seminomas. They tend to occur in younger men, those who are in their late teens to 30s.
What are the risk factors?
Experts don't know exactly what causes testicular cancer. But research has shown that some things can make a man more likely to get it. Things that increase the risk of getting a disease are called risk factors.
Known risk factors for testicular cancer include:
- Undescended testicle (cryptorchidism). This is the main risk factor for testicular cancer. About 1 in 10 cases of testicular cancer occurs in men who have an undescended testicle. A man's risk is higher even if he has had surgery to move the testicle into the scrotum.
- Personal history of testicular cancer. A man who has had cancer in one testicle is at increased risk of getting cancer in the other testicle.
- Family history of testicular cancer. A man is at higher risk if his father or brother has had this cancer.
- Ethnic or racial background. White men are about 5 times as likely to get testicular cancer as African American men and about 3 times as likely as Asian or Native American men. The reason for this difference in risk is not known.
Having any of these risk factors doesn't mean you will get testicular cancer. It only means that your risk may be greater than average. Most men who get testicular cancer don't have any special risk factors.
What are the symptoms?
Symptoms of testicular cancer may include:
- A painless lump or swelling in a testicle
- Swelling or enlargement of a testicle or a change in the way it feels
- A feeling of heaviness in the scrotum
- A dull ache in the lower abdomen or groin
- A sudden buildup of fluid in the scrotum
- Pain or discomfort in a testicle or the scrotum
If you notice any of these symptoms, talk to your doctor right away. These symptoms can be caused by conditions other than cancer, but it's best to get them checked out. If it's cancer, the sooner it's found, the better the outcome.
Created on 10/12/2001
Updated on 06/03/2011
- Memorial Sloan-Kettering Cancer Center. Testicular cancer (germ cell tumors).
- National Cancer Institute. Testicular cancer: questions and answers.
- Ryan CJ, Small EJ, Torti FM. Testicular cancer. In: Abeloff MD, Armitage JO, Niederhuber JE, Kastan MB, McKenna WG, eds. Abeloff's Clinical Oncology. 4th edition. Philadelphia, PA: Churchill Livingstone Elsevier; 2008.
- American Cancer Society. Overview: testicular cancer.