Cancer of the testicles, also known as testicular cancer, is one of the less common cancers. It usually affects younger men between the ages of 15 and 49.

The most common symptom is a painless lump or swelling in the testicles. Other symptoms can include:

• a dull ache in the scrotum (the sac of skin that hangs underneath the penis and contains the testicles)
• a feeling of heaviness in the scrotum

It's important to be aware of what feels normal for you. Get to know your body and see your GP if you notice any changes.

Read more about the symptoms of testicular cancer.

The testicles

The testicles are the two oval-shaped male sex organs that sit inside the scrotum on either side of the penis.

The testicles are an important part of the male reproductive system because they produce sperm and the hormone testosterone, which plays a major role in male sexual development.

Types of testicular cancer

The different types of testicular cancer are classified by the type of cells the cancer first begins in.

The most common type of testicular cancer is known as ‘germ cell testicular cancer’, which accounts for around 95% of all cases. Germ cells are a type of cell that the body uses to help create sperm.

There are two main subtypes of germ cell testicular cancer. They are:

• seminomas, which account for around 40-45% of all germ cell testicular cancers
• non-seminomas, which account for around 40-45% of all germ cell testicular cancers

Seminomas and non-seminomas tend to respond well to chemotherapy, a treatment that uses medication to kill cancer cells.

Less common types of testicular cancer include:

• Leydig cell tumours, which account for around 1-3% of cases
• Sertoli cell tumours, which account for around 1% of cases
• Lymphoma, which accounts for around 4% of cases

This article focuses on germ cell testicular cancer. Contact Macmillan for more information on Leydig cell tumour and Sertoli cell tumour.

Read information about Hodgkin lymphoma and Non-Hodgkin lymphoma.

How common is testicular cancer?

Testicular cancer is relatively uncommon, accounting for just 1% of all cancers that occur in men.

Each year in the UK around 2,300 men are diagnosed with testicular cancer, according to Cancer Research UK.

Testicular cancer is unusual compared to other cancers because it tends to affect younger men. As a result, although relatively uncommon overall, testicular cancer is the most common type of cancer to affect men between the ages of 15 and 49.

Rates of testicular cancer are five times higher in white men than in black men. The reasons for this are unclear.

The number of cases of testicular cancer that are diagnosed each year in the UK has roughly doubled since the mid-1970s. Again, the reasons for this are unclear.

Causes of testicular cancer

The cause or causes of testicular cancer are unknown, but a number of things have been identified that increase the chance of developing the condition. These include:

• having a family history of testicular cancer
• being born with undescended testicles (cryptorchidism). About 3-5% of boys are born with their testicles located inside their abdomen, which usually descend into the scrotum during the first four months of life

Read more about the causes of testicular cancer.

Outlook

Testicular cancer is one of the most treatable types of cancer. More than 96% of men with early stage testicular cancer will be completely cured.

Even cases of more advanced testicular cancer, where the cancer has spread outside the testicles to nearby tissue, have an 80% chance of being cured.

Compared to other cancers, deaths from testicular cancer are rare. Cancer Research UK say that around 70 men die from testicular cancer every year in the UK.

Treatment for testicular cancer includes the surgical removal of the affected testicle (which should not affect fertility or the ability to have sex), and chemotherapy. Less commonly, radiotherapy (a treatment that uses radiation to kill cancer cells) may be used for seminomas.

Read more about treating testicular cancer.

Smoking

If you smoke, giving up will halve your risk of developing testicular cancer, as well as reduce your risk of getting many other serious health conditions, such as lung cancer and heart disease.

If you decide to stop smoking, your GP will be able to refer you to an NHS Stop Smoking Service, which will give you dedicated help and advice about the best ways to give up. You can also call the NHS Smoking helpline on 0300 123 1014. Trained helpline staff can offer free expert advice and encouragement.

If you are committed to giving up smoking but do not want to be referred to a stop smoking service, your GP should be able to prescribe medical treatment to help with withdrawal symptoms you may have.

Read more information about:

• treatments to help you quit smoking
• how to stop smoking

Benign

Benign refers to a condition that should not become life threatening. In relation to tumours, benign means not cancerous.

Malignant

Malignant is a term used to describe a life threatening or worsening condition. In the case of tumours, malignant means cancerous.

Testicles

Testicles are the two oval-shaped reproductive organs that make up part of the male genitals. They produce sperm and sex hormones.

Testosterone

Testosterone is a male sex hormone that is involved in making sperm and sexual characteristics, such as the development of a deeper voice. Testosterone is also found in small amounts in women.