Testicular cancer is a disease in which cancer cells grow in one or both testicles. The testicles (or testes) are a pair of male sex glands that produce sperm and male hormones. They are located under the penis in a sac-like pouch called the scrotum. At the top of each testis is a bunch of tiny tubules that collect and store sperm. This structure is called the epididymis. The sperm travel from the epididymis through the spermatic cord (or vas deferens) and out through the urethra during ejaculation.

The Male Genitalia

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Cancer occurs when cells in the body (in this case testicular cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissues and can spread to other parts of the body. A benign tumor does not invade or spread.

Types of Testicular Cancer

The majority—95%—of cancers that arise in the testicles begin in the germ cells. These are the cells that produce sperm cells, also called spermatozoa. The main types of germ cell cancers are the following:

  • Embryonal carcinoma – more common up to the age of 35
  • Seminoma – more common between the ages of 35 and 75

Sometimes germ cells travel to other areas of the body, such as the chest or abdomen, and may turn into a rare type of cancer called germ cell tumor. These tumors are treated similarly to germ cell tumors that start in the testicles, with the exception of the fact that if the tumor originally started outside of the testicle, then the testicle does not need to be removed.

Many other types of tumors can arise in the testicles, including lymphomas and sarcomas, but they are rare.

Who Is Affected

Testicular cancer occurs exclusively in males, although germ cell tumors of other parts of the body can occur in females. Its highest incidence is between the ages of 20 and 40, younger than nearly all other cancers except those of the blood-forming tissues (such as the leukemias ).

Testicular cancer is the most common form of cancer in young men between ages 20 and 35. The peak annual incidence ranges from 8 to 14 per 100,000 men between ages 20 and 35, with a smaller peak in early childhood. According to cancer statistics, 7,500 new cases of testicular cancer were diagnosed and 400 men died of their disease in the United States in the year 2002. The highest incidence occurs in northern Europe and North America, while the lowest rates are found in Asia and Africa. Whites have five times more testicular cancer than blacks. The rate increases with socioeconomic status, independent of race.

The prognosis of testicular cancer has improved dramatically in the last 20 years with the discovery of effective chemotherapy regimens. The large majority of patients with this cancer are cured, although the likelihood of cure still depends on the stage at diagnosis and other factors.


The causes of testicular cancer are unknown. Several risk factors have been identified, including:

  • Undescended testes (cryptorchidism)
  • Family history of testicular cancer
  • HIV infection
  • Prior history of testicular cancer (men who have had a cancer in one testicle are more likely than the average person to develop a cancer in the other testicle).

Normally, the testes, which are inside the abdomen during gestation, migrate into the scrotum by the time of birth. Occasionally, though, boys are born with testes that are still in the abdomen or in the groin, not having completed their journey to the scrotum. This is called undescended testes. These testes are at high risk of cancer and should be moved into the scrotum or removed entirely, although this may not prevent the development of a cancer. Accumulated data suggest that cryptorchism and cancer are both the result of an underlying hereditary or congenital condition, rather than simple cause and effect.

Major Complications

Cancer in the testicles can spread both through the lymphatic system and the blood. Spread through the lymphatic system is very common, and leads to cancer involving the lymph nodes in the retroperitoneum (the area in the back of the abdomen). In advanced stages of the disease, cancer may also spread into the lungs and other organs.

Complications may occur following successful treatment. Chemotherapy may cause Raynaud's phenomena (a circulatory disorder that decreases blood flow to the fingers and sometimes ears, nose, and lips), or damage to the kidneys, nerves, or lungs. The surgical treatment known as retroperitoneal lymph node dissection may cause ejaculatory dysfunction. Fifteen percent of patients cured of testicular cancer report sexual dysfunction. Treatment can also lead to infertility (inability to father a child) due to low sperm count. For this reason, sperm banking (freezing of sperm samples) is often recommended prior to chemotherapy.

This Report Covers the Following:

Risk factors – factors that increase your chances of developing testicular cancer.
Reducing your risk – steps you can take that may help decrease your risk of developing testicular cancer.
Screening – when you don't have symptoms of cancer, screening tests offer a way to determine if you are at risk for or if you have testicular cancer.
Symptoms – changes in your health that should prompt you to see your doctor for further evaluation.
Diagnosis and prognosis – the steps your doctor will take to find out if you have testicular cancer. And if you do have cancer, the testing that will determine how far it has progressed.
Treatment – the goals and options for treatment of testicular cancer.
Living with testicular cancer – one man shares his experiences with testicular cancer.
Talking with your doctor – questions to ask your doctor about your case of testicular cancer.
Resources – places to go for further information on testicular cancer.