Introduction
Testicular cancer is where an abnormal growth develops in the testicles. Normally only one testicle is affected. This type of cancer is not very common in the general population, with around 800 men affected in Australia every year, however in the age group 20-39 it is the second most common cancer diagnosis in men, behind skin cancer.
There are a few different types of testicular cancer, the most common of which are 'germ cell tumours' - these are tumours that develop in cells which become sperm cells.
Around 90%-95% of all testicular cancer diagnoses are germ cell tumours. Germ cell tumours are sub-divided into 'seminoma' and 'non-seminoma' types, with the seminoma type being slower growing and developing in an older age group (25-45) and the non-seminoma type being faster growing and developing in a younger age group (late teens to early twenties).
There are also a small number of testicular cancers that develop outside the testicle itself in the connected tissue and in the hormone producing tissue. These are generally benign (i.e. not cancerous) and are referred to as 'stromal' tumours.
Testicular cancer has a high cure rate - over 95%. However, if it is not detected or treated, cancer can spread from the testicles to other parts of the body.
Causes
It is not known precisely what causes testicular cancer, however certain risk factor for the condition have been identified. These are:
Age
Men between the ages of 20-40 are more at risk
Cryptorchidism
This is where the testes (the medical terms for the testicles) have not descended into the scrotum. The testes develop in the abdomen before birth and 'descend' into the scrotum at some point before the first birthday. Where they have not descended by the age of three, surgery to correct this will be needed to prevent permanent damage to them. Up to 5% of young boys are affected by cryptorchidism.
Family history
Where a close relative e.g. father / brother / uncle has or has had the condition (although this is a small risk with around 2% of diagnoses linked to hereditary factors).
Infertility
Infertility shares a number of common risk factors with testicular cancer.
HIV
Men with HIV are at increased risk of developing the condition.
Previous incidence
If a man has previously had testicular cancer in one testicle, this increases the risk of it occurring in the other testicle (1 in 25 men are affected).
ITGCN
ITGCN stands for 'Intratubular Germ Cell Neoplasia'. It is sometimes found when assessing the possible causes of infertility in men. It is not cancerous, however there is a 50% chance of it developing into testicular cancer within a five-year period. Between 5%-10% of men diagnosed with testicular cancer are found to have ITGCN.
It is important to note that the following are NOT risk factors for testicular cancer:
- Injury to, or strains of, the scrotum / testicles.
- Hot baths.
- Wearing tight clothing.
- Sexual activity.
- Vasectomy.
Symptoms
The main outward symptom of the condition is a hard lump in a testicle, normally painless, however there are often no noticeable symptoms. Symptoms which may appear include:
- Persistent backache.
- Sensation of 'heaviness' in the scrotum.
- Change in size / shape of testicles or unevenness.
- Pain in the testicles / lower abdomen.
Most of these symptoms, including the discovery of a lump or lumps in a testicle, are not caused by testicular cancer, however it is important that you see a doctor if you have any of these symptoms.
Tests / Diagnosis
To assess whether testicular cancer is present, a doctor will review medical history and perform a physical examination and an ultrasound scan of the testicles. Blood tests (to check for hormone 'markers' which may indicate the presence of testicular cancer) and other scans may also be required. Many lumps are found to be non-cancerous fluid-filled cysts.
If there is a possibility that cancer has spread to other parts of the body, further scans (CT scan) may be required.