What Is Testicular Cancer? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Testicular cancer is a relatively rare cancer with a relatively good prognosis.

Cancer is a disease characterized by the abnormal, out-of-control growth of cells.

Testicular cancer, as its name suggests, occurs when malignant or cancerous cells form in the tissues of one or both of a man's testicles.

According to the American Cancer Society (ACS), more than 90 percent of testicular cancers form in germ cells, which are the cells that produce sperm.

There are two main types of testicular germ cell tumors: seminomas and non-seminomas. Non-seminomas grow and spread more quickly than seminomas, and are less sensitive to radiation treatment.

In some cases, testicular cancer may be "secondary," meaning that the cancer started in another organ and spread to the testicles.

Tumors can also develop in the stroma — the supportive, hormone-producing tissues of the testicles. These stromal tumors are usually benign.

Testicular Cancer Statistics

Testicular cancer is the most common cancer affecting males between the ages of 15 and 35, according to the National Institutes of Health (NIH).

But testicular cancer is still relatively rare, affecting only about 1 out of every 263 males (about 0.4 percent) in the United States, according to the ACS, which notes that 8,430 new cases of testicular cancer are expected in 2015.

In 2012, there were 233,602 men living with testicular cancer in the United States, according to the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program.

Overall, testicular cancer is currently the 25th most common cancer in the United States, according to SEER data. It accounts for only 0.5 percent of all new cancer cases in the country.

Risk Factors

It's unclear what, exactly, causes testicular cancer to develop in some people but not in others.

However, it is known that certain risk factors increase your risk of developing testicular cancer.

Testicular cancer can affect males of any age, but it's most common in young men between the ages of 20 and 34, according to the ACS.

It's also more common in white males than in men of other races.

In fact, the risk of testicular cancer for white males is 4 to 5 times higher than for black and Asian-American males, according to the ACS.

The risk for Hispanic and American Indian or Alaska Native males is lower than for white males but higher than for black and Asian-American males.

You're also at increased risk for testicular cancer if you have:

• Abnormal testicle development
• An undescended testicle
• A family history of testicular cancer
• HIV
• A prior case of testicular cancer
• Klinefelter syndrome , in which you have an extra X chromosome
• Carcinoma in situ, a non-invasive type of testicular germ cell tumors

In addition, men who use marijuana may have a higher risk of developing testicular germ cell tumors, according to 2012 report in the journal Cancer.

Prognosis of Testicular Cancer

In the United States, some 380 men are expected to die from testicular cancer in 2015, according to the ACS.

However, the prognosis for men with testicular cancer tends to be positive because the disease can usually be treated successfully.

A man's lifetime risk of dying from testicular cancer is about 1 in 5,000, the ACS reports.

Cancer death risk is generally measured by the 5-year survival rate, or the percentage of people who are alive at least 5 years after being diagnosed.

The so-called relative 5-year survival rate takes into account causes of death unrelated to the cancer.

The relative 5-year survival rate for all testicular cancers is 95 percent, according to SEER statistics.

If the cancer hasn't spread beyond the testicles, the 5-year survival rate is 99 percent.

If the cancer has spread to regional lymph nodes or distant tissues, the 5-year survival rates are 96 percent and 74 percent, respectively.

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