Each year about 9,000 men in the U.S. are diagnosed with testicular cancer. Most are under age 35, though the disease can affect boys and men at any age.
- What is testicular cancer?
- Types of testicular cancer
- Causes and risk factors
- Next steps
What is testicular cancer?
Cancer occurs when cells begin to grow abnormally. They do not respond to regular cell growth, division and death signals like they are supposed to. They also don’t organize normally. Instead they grow into a tumor, which may break through surrounding layers of cells.
Testicular cancer occurs in the cells of one or both testicles. Sometimes called testes, these oval-shaped glands are inside the sac of skin (scrotum) directly behind the penis. Testicles make male hormones and produce sperm.
Types of testicular cancer
Because there are different types of cells in the testicles, there are different types of testicular cancer, and they are treated differently.
The cells that make sperm are called germ cells. Most testicular cancers begin as one of two types of germ-cell tumors: seminoma or nonseminoma. A third type of testicular tumor is called a stromal tumor.
- Seminomas — typically occur in men in their late 30s to early 50s but can occur at any age. These tumors usually respond well to radiation therapy and chemotherapy.
- Nonseminomas — usually found in men from their late teens to early 40s. These tumors tend to be more aggressive than seminomas and spread rapidly. Chemotherapy is often very effective in treating them.
- Stromal tumors — grow in the cells that make hormones and in the supportive tissues of the testicles. Most of the time, these tumors are not cancerous and do not spread beyond the testicle. When they are cancerous and do spread, they need aggressive treatment.
Cancer that starts somewhere else in your body can spread to your testicles and form tumors there. These are called secondary tumors. They are the most common form of cancer in the testicles in men over 50. Treatment depends on the type of cancer and often involves surgery, radiation therapy and chemotherapy.
Symptoms of testicular cancer
The most common testicular cancer symptom is a lump in one of your testicles. Sometimes a man finds a lump during a self-exam, or your doctor may find a suspicious lump during a physical before you notice anything yourself.
If you have any of these symptoms, see your doctor to look into the reason:
- Painless lump or swelling in your testicle
- Pain or discomfort in your testicle or scrotum
- Dull ache in your lower abdomen or groin
- Sudden build-up of fluid in your scrotum
- Feeling of heaviness in your scrotum
- Enlarged or tender breasts
- Loss of sex drive
Diagnosing testicular cancer
Your doctor will ask about your medical history and do a physical exam, including feeling your testicles for lumps or swelling and your abdomen for enlarged lymph nodes.
Next, you will have a series of tests, such as blood tests and one or more imaging tests, like an ultrasound, X-ray or computed tomography (CT), magnetic resonance imaging (MRI) or positron-emission tomography (PET) scan.
If your doctor believes you have testicular cancer based on your exam and tests, they will likely recommend surgery to remove the testicle. Then a pathologist will check tissue from the tumor under a microscope to confirm the presence of cancer and give you and your team details about the type and extent.
What causes testicular cancer?
Doctors don’t know the exact cause of testicular cancer. Research is ongoing to learn more about the possible causes and risk factors.
While testicular cancer can occur at any age, it is most often a disease of young men. Men between the ages of 20 and 34 are at higher risk.
For reasons that scientists do not understand, white men are more likely to develop testicular cancer than African-American, Asian or Hispanic men.
The following factors may also increase your risk; however, many men with testicular cancer do not have any of these risk factors.
- Undescended testicle (cryptorchidism) — a condition in which one or both testicles do not move down from the belly (where they develop) into the scrotum. This is the main risk factor for testicular cancer.
- Abnormal development — including abnormalities of the testicles, penis or kidneys.
- Inguinal hernia — when tissue in the lower abdomen bulges out through a weak spot or hole in the abdominal muscles.
- Klinefelter syndrome — in which a male is born with an extra X chromosome, causing low levels of male hormones, infertility, breast enlargement and small testicles.
- History of cancer in one testicle — which increases the risk of developing it on the other side.
- Family history of testicular cancer — such as in your father or brother.
- Human immunodeficiency virus (HIV) — which may slightly increase your risk.