What is it?
Testicular cancer is an abnormal, uncontrolled growth of cells that forms a tumour in one or both testicles. Men have two testicles (testes, gonads) that are located in the scrotum, the pouch of loose skin below the base of the penis. The testicles are responsible for producing sperm and male hormones (mainly testosterone) that regulate reproductive organ development.
Testicular cancer is the most common cancer in males between 20 and 40 years of age. About 2,000 men are diagnosed with the condition in the UK each year. It is several times more common in white males than in men of African, Hispanic, or Asian descent, although the cause for this additional risk is not known. Other factors that can increase risk include undescended testicles (cryptorchidism) if not corrected before the age of 11, abnormal development of the testes (gonadal dysgenesis), inflammation of the testes (orchitis) which can rarely occur after mumps, genetic disorder called Klinefelter’s syndrome, and a family history of testicular cancer. Individuals who handle pesticides, leather workers, miners, oil well workers, and HIV positive persons also appear to be at higher risk.
Germ cells, which normally develop into sperm, account for about 94% of testicular tumours. These tumours are devided into two groups, seminomas (40%) and non-seminomas (60%). Seminomas occur most ofter in men in their thirties. They tend to grow very slowly and usually do not spread (metastasize). Non-seminomas mainly affect men in their twenties and tend to grow and spread more quickly.
About 4-5% of all testicular tumours (20% children) form in the cells that produce hormones. These tumours may secrete oestradiol, a female sex hormone which can then cause breast growth (gynaecomastia).
Testicular cancer is usually first detected as a painless lump or swelling about the size of a pea on the front or side of one testicle. It is most often found by the patient, but may also be found during a routine physical examination or during a medical examination done for other purposes such as the investigation of infertility. The cancer may give no warning signs or it may be due to symptoms such as a heaviness or collection of fluid in the scrotum, a dull ache in the abdomen or groin, pain in the testicle and an enlargement or tenderness in the breasts. If you have these symptoms you should discuss them with your GP, but you should keep in mind that they may not be due to cancer.
If testicular cancers are found early they can be easily treated, and so young men should examine themselves once a month or so after a warm bath or shower when the skin of the scrotum is relaxed.
The reasons for testing are to detect and help diagnose testicular cancer, to distinguish between different types, to determine how far it has spread, to follow the effectiveness of treatment and to monitor for recurrence.
Non-laboratory tests
The diagnosis of testicular cancer begins with a physical examination by your GP after you have explained your symptoms. If your GP suspects that the lump in your testicle may be cancer, you will be referred to a hospital for further tests.
A scrotal ultrasound scan is a painless procedure that uses high-frequency sound waves to produce an image of your testicle. It will help the radiologist decide whether the lump is solid or filled with fluid. A lump filled with fluid is known as a cyst and is usually harmless. A more solid lump may be a sign of cancer.
If laboratory tests (below) suggest testicular cancer, you may have a chest X-ray to check for signs that the tumour has spread. You may also need a scan of your entire body, such as magnetic resonance imaging (MRI) or computerised tomography (CT).
Laboratory tests
Testicular cancer often produces substances that can be measured in your blood. The tumour markers that are usually measured to help confirm the diagnosis are
- AFP (alpha-fetoprotein)
- hCG (human chorionic gonadotropin)
- LDH (lactate dehydrogenase)
AFP is almost always elevated in non-seminomas while hCG may be elevated in both seminomas and non-seminomas. As well as helping the diagnosis of testicular cancer, if the initial levels are raised they can be used to follow response to treatment and monitor for recurrence. LDH is elevated in most testicular cancers. It is an enzyme found in many body tissues that is released into the bloodstream when cellular damage occurs. It is not specific for testicular cancer but can help the doctor decide the stage and risk for both tumour types. There is still a small chance that you have testicular cancer even if all your blood test results are normal.
The only way to be sure whether a testicular mass is cancerous is to do a biopsy. If cancer is suspected, the testicle is usually removed and looked at by a pathologist. A cut is made in the groin and the testicle and spermatic cord (which contains the vas deferens) are taken out of the scrotum.
If the lump is cancerous, a pathologist will report the type of testicular cancer and the risk that cancer has spread. The preferred treatment will depend on the type and stage of cancer.
Testicular cancer is one of the most curable forms of cancer, more than 95% of men with early stage disease being completely cured. However, most types will spread if left undiscovered, invading blood and lymph vessels and being carried to other body organs such as the lungs. Early detection and treatment is important to improve the likelihood of a cure.
The main form of treatment for testicular cancer is removal of the affected testicle - orchidectomy. (Losing a single testicle does not affect sex life or the ability to have children.) Often radiation or chemotherapy is used as well. Radiation is a common follow-up treatment for seminomas because these tumours are particularly sensitive to it. Non-seminomas respond better to chemotherapy using anti-cancer drugs. Chemotherapy may also be used when treating advanced or resistant cases.
Depending on the results of the laboratory investigations, raised levels of LDH, AFP or hCG may be monitored to watch the response to treatment and look for possible recurrence. Doctors may also use X-rays and CT or MRI scans for monitoring.
Testicular cancer treatments continue to evolve. High-dose chemotherapy in conjunction with stem cell (bone marrow) transplantation has offered some encouraging results. Since every case of testicular cancer and every man's response is unique, those affected should work with their doctor and/or cancer team to determine the best course of action.