What is Testicular Cancer?

Testicular cancer, also known as cancer of the testes, occurs when germ cells (the cells that become sperm) experience abnormal growth. Germ cells, like stem cells, have the potential to form any cell in the body. Normally this ability is dormant until the sperm fertilizes an egg. When germ cells become cancerous, they multiply unchecked, forming a mass of cells called a tumor, and invade normal tissue.

Testicular cancer can metastasize, meaning that it can spread to other parts of the body. During metastasis cells leave the original tumor and migrate to other parts of the body through blood and lymph vessels, forming a new tumor. Testicular cancer metastasis most often involves the abdomen, lungs and brain. Testicular cancer can spread rapidly and is deadly if left untreated.

Testicular cancer has a very fast onset. Testicular cancer grows rapidly, with tumors doubling in size in just 10 to 30 days.


  • Seminomas involve a uniform type of cell and spread less aggressively. Approximately 40% of testicular cancers are seminomas. When testicular cancer is first diagnosed, three-quarters of seminoma cases have not spread beyond the testes.

  • Non-seminomas involve a mixture of cell types, and are much more aggressive than seminomas. When testicular cancer is first diagnosed, two-thirds of non-seminoma cases have already spread to the lymph nodes.

Luckily, germ cell tumors involve relatively primitive cells, making them more susceptible to treatment. This is why testicular cancer has one of the highest cure rates of any cancer.

Testicular cancer is a relatively rare form of cancer, representing about 1% of cancers affecting men. However, it is the most common form of cancer between the ages of 15 and 44. 78.7% of testicular cancer cases occur in men between the ages of 20 and 44 and 90.4% between the ages of 20 and 54.

It is estimated that there will be 8,980 new cases of testicular cancer in 2004, and 360 deaths. Testicular cancer incidence rates have been increasing steadily by about 2.1% per year, from 3.3 cases per 100,000 persons in 1974 to 4.0 per 100,000 persons in 1984 to 4.9 cases per 100,000 persons in 1994 and 6.1 cases per 100,000 persons in 2000. At the same time, mortality rates have been dropping. In 1950-54 the five-year survival rate was 57%. This improved to 63% in 1963, 79% in 1974-76, 91% in 1983-85, and 95% in 1992-98. The decline in mortality rates is primarily due to the introduction of more effective treatments, such as the BEP (bleomycin, etoposide and cisplatin) chemotherapy regimen.

Testicular cancer is much more common among white men than black, hispanic, asian and native american men, with 93% of testicular cancers occuring in white men. Five-year survival rates are highest among white men, but overall prognosis for all races is good. (The median age of testicular cancer patients at diagnosis is 34 for white men ant 43 for black men. Black men have 10% fewer stage I cases than white men, and 2% more stage II and 8% more stage III. This probably accounts for the differences in survival rates.) Incidence rates are higher in more developed countries, and also increase with socio-economic status.

The lifetime risk of being diagnosed with testicular cancer is 0.35%. The lifetime risk for white men is 0.42% and for black men it is 0.10%. The lifetime risk of dying of testicular cancer is 0.02%.

Testicular cancer is not contagious.

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