Cancer that develops in a testicle is called testicular cancer or cancer of the testis. Usually only one testicle is affected, but in some cases both. About 90 to 95 per cent of testicular cancers start in the cells that develop into sperm – these are known as germ cells.

Compared with other types of cancer, testicular cancer is rare. But testicular cancer is the second most common cancer in young people (aged 18 to 39) excluding non-melanoma skin cancer. The average age at diagnosis is 37 years old. However, this form of cancer is highly treatable, even when cancer has spread beyond the testicle.

The most common testicular cancers are germ cell tumours. There are two main types, seminoma and non-seminoma. Seminoma usually occurs between the ages of 25 and 45 years and tends to develop more slowly than non-seminoma cancers. Non-seminomas are more common in younger people, usually in their late teens or early 20s.

It is estimated that 1,026 people were diagnosed with testicular cancer in 2024. In 2023, a total of 33 deaths from testicular cancer were estimated. In 2016 – 2020, on average 97.6% of those diagnosed with testicular cancer survived 5 years after diagnosis.

Testicular cancer may cause no symptoms. The most common symptom is a painless swelling or a lump in a testicle.

Less common symptoms include:

• Feeling of heaviness in the scrotum;
• Change in the size or shape of the testicle;
• Pain or ache in the lower abdomen, the testicle or scrotum;
• Back pain;
• Feeling of unevenness;

Tenderness or tenderness of the breast tissue (due to hormones created by cancer cells).

• A couple of factors that may increase a man’s risk of testicular cancer include an undescended testicle as an infant, or family

   history, mainly having a father or brother who has had testicular cancer.

  There is no known link between testicular cancer and injury to the testicles, hot baths, wearing tight clothes or sporting strains.

Treatment for testicular cancer depends on the type of cancer you have and how far it has spread. Your medical team will advise the best treatment for you. They will consider various points:

• your general health
• the type of testicular cancer
• the size of the tumour
• the number and size of any lymph nodes involved
• if the cancer has spread to other parts of your body. If testicular cancer does spread, it most commonly spreads to the lymph nodes in the pelvic and lower abdominal regions.

In almost all cases, if testicular cancer is suspected, the affected testicle is surgically removed in an operation called an orchidectomy. A laboratory will then examine the tissue to confirm the type of cancer and the stage it is at.

After the surgery, you may not need any further treatment but you will be closely monitored. This is called surveillance. If additional treatments are required they may include chemotherapy or radiotherapy to eradicate any cancer cells that may have spread to other parts of the body. Others may need further surgery. 

Several decades ago testicular cancer was a disease with a very poor prognosis. But now, because of new treatments, tested carefully in clinical trials, it is almost always curable even when it has spread. However, even though there are excellent treatments available, we still need to do more. This can only happen through understanding the science and by performing clinical trials to see which treatments are the ones most likely to help further improve outcomes.

ANZUP is involved in clinical trials in testicular cancer through its clinical trials program. Speak with your doctor if you would like to know more about testicular cancer clinical trials.