What is testicular cancer?
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 are affected. About 90-95% of testicular cancers start in the cells that develop into sperm – these are known as germ cells.
Sometimes testicular cancer can spread to lymph nodes in the abdomen, or to other parts of the body.
The testicles
The testicles are two oval glands that sit behind the penis in a pouch of skin called the scrotum. They are part of the male reproductive system and are also called testes (or a testis, if referring to one).
Role of the testicles
The testicles produce and store sperm. They also produce the male hormone testosterone, which is responsible for the development of male characteristics, such as facial hair, a deeper voice and increased muscle mass, as well as sexual drive (libido).
Epididymis, spermatic cord and vas deferens
A tightly coiled tube at the back of each testicle called the epididymis stores immature sperm. The epididymis connects the testicle to the spermatic cord. The spermatic cord runs through the groin region into the pelvis and contains blood vessels, nerves, lymph vessels and a tube called the vas deferens. The vas deferens carries sperm from the epididymis to the prostate gland.
Seminal vesicles and prostate gland
Two small glands called seminal vesicles sit above the prostate gland. The seminal vesicles and prostate gland produce fluids that make up a large part of semen. Semen also contains sperm from the testicles and is ejaculated from the penis during sexual climax.
Lymph nodes and vessels
There are many lymph nodes (also called lymph glands) and lymph vessels around the testicles and in the abdomen. These are part of the lymphatic system and are important for resisting and fighting disease (immunity). The nodes and vessels also drain lymphatic fluid (lymph) from the tissues back into the bloodstream.
What types are there?
The most common testicular cancers are called germ cell tumours. There are two main types, which look different under a microscope.
Germ cell tumours
seminoma
- tend to develop more slowly than nonseminoma cancers
- usually occur in men aged 25-45, but can occur in older men
non-seminoma
- rarer cancers that tend to develop more quickly than seminoma cancers
- more common in younger men in their late teens and early 20s
- there are four main subtypes: teratoma, choriocarcinoma, yolk sac tumour and embryonal carcinoma
Sometimes a testicular cancer can include a mix of seminoma cells and non-seminoma cells, or a combination of the different subtypes of non-seminoma cells (mixed tumours). When there are seminoma and non-seminoma cells mixed together, doctors treat the cancer as if it were a non-seminoma cancer.
A small number of testicular tumours start in cells that make up the supportive (structural) and hormone-producing tissue of the testicles. These are called stromal tumours. The two main types are Sertoli cell tumours and Leydig cell tumours. They are usually benign and are removed by surgery.
Other types of cancer, such as lymphoma, can also involve the testicles. For information about lymphoma, call Cancer Council 13 11 20 or visit your local Cancer Council website.
Intratubular germ cell neoplasia (ITGCN)
Some germ cell cancers begin as a condition called intratubular germ cell neoplasia (ITGCN or IGCN). In this condition, the cells are abnormal, but they haven’t spread outside the area where the sperm cells develop. ITGCN is not cancer but it has about a 50% risk of turning into testicular cancer within five years. About 5-10% of men diagnosed with testicular cancer have ITGCN.
ITGCN has similar risk factors to testicular cancer. It is hard to diagnose because there are no symptoms and it can only be found by testing a tissue sample. Once diagnosed, some cases of ITGCN will be carefully monitored ( surveillance). Other cases will be treated with radiation therapy or with surgery to remove the testicle.
What are the risk factors?
The causes of testicular cancer are unknown, but certain factors may increase a man’s risk of developing it:
Personal history
Men who have previously had cancer in one testicle are more likely to develop cancer in the other testicle. ITGCN is also a risk factor (see above).
Undescended testicles
Before birth, testicles develop inside the abdomen. By birth, or within the first six months of life, the testicles should move down into the scrotum.
If the testicles don’t descend by themselves, doctors perform an operation to bring them down. Although this reduces the risk of developing testicular cancer, men born with undescended testicles are still more likely to develop testicular cancer than men born with descended testicles.
Family history
Sometimes gene mutations are passed on in families. A man with a father or brother who has had testicular cancer is slightly more at risk of cancer. However, family history is only a factor in a small number (about 2%) of men who are diagnosed with testicular cancer. If you are concerned about your family history of testicular cancer, you can ask your doctor for a referral to a urologist. The urologist can provide advice on self-examination for you and your family members.
Infertility
Having difficulty conceiving a baby (infertility) is associated with ITGCN (see above), undescended testicles and, occasionally, genetic abnormalities. Because these are risk factors for testicular cancer as well, infertility is also considered a risk factor for testicular cancer.
There is no known link between testicular cancer and injury to the testicles, sporting strains, hot baths, wearing tight clothes, sexual activity or having a vasectomy.
HIV and AIDS
There is some evidence that men with HIV (human immunodeficiency virus) and AIDS (acquired immune deficiency syndrome) have an increased risk of testicular cancer, although the reasons are unknown.
Some congenital defects
Some men are born with an abnormality of the penis called hypospadias. This causes the urethra to open on the underside of the penis, rather than at the end. Men with this condition are at increased risk of testicular cancer in the future. Likewise, there may be an increased risk for men born with a lump in the groin known as an inguinal hernia, even when it has been repaired.
How common is it?
Testicular cancer is not a common cancer, but it is the most commonly diagnosed cancer after skin cancer in men aged 20-39. 3 In Australia, about 850 men are diagnosed with testicular cancer each year, accounting for about 1% of all cancers in men. It occurs most often in men aged 25-40. 4
What are the symptoms?
In some men, testicular cancer does not cause any noticeable symptoms, and it may be found during tests for other conditions. When there are symptoms, the most common ones are a swelling or a lump in the testicle (usually painless) and/or a change in a testicle’s size or shape (e.g. hardness or swelling). These symptoms don’t necessarily mean you have testicular cancer. They can be caused by other conditions, such as cysts, which are harmless lumps in the scrotum. However, if you have a lump that is growing quickly, see your doctor urgently.
Occasionally, testicular cancer may cause other symptoms such as a feeling of heaviness in the scrotum; a feeling of unevenness between the testicles; aches or pain in the lower abdomen, testicle or scrotum; enlargement or tenderness of the breast tissue (gynaecomastia); back pain; and/or stomach-aches. If you are concerned about any of these symptoms, make an appointment to see your doctor.
Which health professionals will I see?
Your general practitioner (GP) will organise the first tests to assess your symptoms. If these tests don’t rule out cancer, you will usually be referred to a specialist called a urologist for further tests and procedures. If testicular cancer is confirmed, the specialist will consider treatment options. Often these will be discussed with other health professionals at a multidisciplinary team (MDT) meeting. During and after treatment, you will see various health professionals who specialise in different aspects of your care.
| Health professionals you may see | Role |
| urologist* | treats diseases of the male and female urinary systems and the male reproductive system, including testicular cancer; performs surgery |
| medical oncologist* | treats cancer with drug therapies such as chemotherapy |
| radiation oncologist* | treats cancer by prescribing and coordinating a course of radiation therapy |
| nurses | administers drugs and provides care, information and support throughout treatment |
| cancer care coordinator | coordinates your care, liaises with other members of the MDT and supports you and your family throughout treatment; care may also be coordinated by a clinical nurse consultant (CNC) or clinical nurse specialist (CNS) |
| anaesthetist* | administers anaesthetic before surgery and monitors you during the operation |
| dietitian | recommends an eating plan to follow while you are in treatment and recovery |
| social worker | links you to support services and helps you with emotional, practical or financial issues |
| psychologist, counsellor | help you manage your emotional response to diagnosis and treatment |
| physiotherapist, occupational therapist | assist with physical and practical problems, including restoring movement and mobility after treatment and recommending aids and equipment |
*Specialist doctor