MEN'S HEALTH MATTERS:Risk factors for testicular cancer include having an undescended testicle, writes THOMAS LYNCH.
Q What does a risk factor for developing testicular cancer mean? Does an undescended testicle increase your risk of developing testicular cancer? Are there different types of testicular cancer or are they all the same? How would I know if I have testicular cancer?
AThe testicles are the male reproductive organs producing sperm and they are also responsible for the production of the male hormone testosterone.
In adult men, each one is normally somewhat smaller than a golf ball.
They are in the scrotum because they need to be at a lower temperature (one degree lower) than body temperature to produce sperm.
Sperm cells are carried from the testicles through small tubes (vas deferens) to the seminal vesicles. Fluid from the seminal vesicles and from the prostate gland is added to the sperm to form semen.
A man’s lifetime chance of having testicular cancer is about one in 300. Because treatment is so successful, the risk of dying from this cancer is very low: about one in 5,000.
A risk factor is something that affects a person’s chance of getting a disease. Different cancers have different risk factors.
Some risk factors, such as smoking, can be controlled. Others, like a person’s age or race, can’t be changed.
But having a risk factor, or even many, does not mean that a person will get the disease. Just as having no risk factors doesn’t mean you won’t get the disease.
Most men with testicular cancer do not have any of the known risk factors and we do not know the exact cause of most cases of testicular cancer.
The most significant risk factor for testicular cancer is an undescended testicle.
Men who have had testicular cancer are at increased risk of developing cancer in the other testicle and the risk is also greater in men whose brother or father has had the disease.
About 10 per cent of testicular cancer cases occur in men who have had an undescended testicle (cryptorchidism) and this topic has been covered previously in this column.
Normally, the testicles descend from inside the abdomen into the scrotum before birth. The risk of testicular cancer is increased in males with a testicle that does not move down into the scrotum.
The risk is higher for men with a testicle in the abdomen as opposed to one that has moved down at least part way towards the scrotum. This risk does not change even after surgery to move the testicle into the scrotum.
Most cancers develop in the testicle that has not descended. However, up to 25 per cent of cases occur in the normal testicle.
Because of this it has been postulated that cryptorchidism is not the direct cause of testicular cancer but that some other problem causes both the cancer risk and the cryptorchidism.
The testicles have several kinds of cells and any of these may develop a cancer.
It is important to know which kind of cell the cancer started from because these types of cancer are treated differently and differ in their clinical course.
Germ cell tumours arise in the “germ” or sperm-producing cells and are the most common type of testicular tumours, with nine out of 10 cancers starting here. The two main types are seminomas and non-seminomas.
Seminomas usually develop in men between their late 30s and early 50s whereas non-seminomas tend to develop earlier in life, in men from their late teens to early 40s. There are four main sub-types and most tumours are mixed, having at least two different sub-types.
Tumours can also grow in the cells that make hormones and in the supportive tissues, or stroma, of the testicles.
They are often benign (not cancer), they usually do not spread beyond the testicle and can be cured by surgical removal.
But a few stromal cell tumours spread to other parts of the body (metastasise). Metastatic stromal cell tumours have a poor outlook because they do not respond well to chemotherapy or radiation therapy.
The two main types of stromal tumours are Leydig cell tumours and Sertoli cell tumours. Secondary testicular tumours rarely develop from cancer that has spread to the testicles from other parts of the body.
Most testicular cancers are found by men themselves. It is advisable for all men to examine themselves regularly for any abnormalities even if they do not have any risk factors.
Men should see a doctor if they notice any change in the testicle such as any enlargement or lump in the testicle.
You may suddenly notice some discomfort in the testicle or a sudden collection of fluid in the scrotum.
These symptoms can be caused by cancer but more often there is nothing to worry about and a simple check by your general practitioner will reassure you.
This weekly column is edited by Thomas Lynch, consultant urological surgeon, St Jamess Hospital, Dublin.
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