Testicular cancer

The cause of testicular cancer, as with other cancers, is damage to cellular DNA. This damage results in uncontrolled cell growth, which leads to the formation of a tumour. A tumour can continue to grow and invade surrounding tissues, at which point it becomes a cancer. It can also spread to other areas of the body (metastasise). The exact cause for this cellular damage in the testes is not known.

The male reproductive system

The male reproductive system comprises certain key structures: testes, epididymis, vas deferens, seminal vesicles, prostate and the penis.

The male reproductive system. 

There are generally two testes that are contained in the scrotum, a loose pouch of skin, which can contract and stretch to help keep a constant temperature for the testes. The left testis normally hangs lower than the right. The testes have two major functions - to produce sperm and male sex hormones. For the testes to function optimally, they need to be kept at a constant temperature. The testes are made up of several types of cells. Germ cells are the sperm-producing cells, Sertoli cells are the supporting cells, and Leydig cells are the hormone-producing cells.

The sperm migrate up through the epididymis, where they continue to mature. They are then delivered, via the vas deferens, to the seminal vesicles, which is where they are stored until time for ejaculation through the prostate and penis.

Types

Testicular cancer can be categorised based upon the type of cell it originates from. Each of the cell types can develop into a cancer. It is important to distinguish between these different cell types, as the treatment and prognosis can differ accordingly. The types of testicular cancer include:

Germ cell tumours

The vast majority of testicular cancers (90%) originate from germ cells. Generally, there are two main types of germ cell tumours - seminomas and non-seminomas.

Seminomas

Most seminomas occur in men mainly between the ages of 25 and 45 years. Rarely, there is also a slow-growing seminoma, which occurs mainly in older men, around the age of 65. They tend to grow and spread slower than non-seminomas. Some seminomas produce a hormone called human chorionic gonadotropin (hCG), which can be measured by a blood test called a tumour marker (see below).

Non-seminomas

There are four main types of non-seminomas - teratoma, embryonal carcinoma, choriocarcinoma and yolk sac carcinomas (orchidoblastoma). These tend to occur in men between the ages of 15 and 35 years. Yolk sac carcinomas are the most common type of testicular cancer affecting children.

Non-seminomas also produce hormones that can be measured by tumour markers - embryonal carcinoma produces alpha-fetoprotein (AFP) and HCG, choriocarcinoma produces HCG, and yolk sac carcinoma produces AFP. Commonly, non-seminomas are a mix of the different types. This usually does not change the general approach to treatment. In some cases, there can also be a mix of seminoma and non-seminoma cells, in which case it is referred to as a mixed germ cell tumour. These are generally treated as non-seminomas, as they share similar growth patterns and treatment responses.

Stromal tumours

A rare type of testicular cancer, stromal tumours, originate in the supportive and/or hormone-producing cells of the testes. The two types of stromal tumours are Sertoli cell and Leydig cell tumours. These are usually benign tumours, but can occasionally be cancerous.

Other cancers

Cancers from other areas of the body can spread to the testes. These include lymphoma, leukaemia, prostate cancer, lung cancer and melanoma.

Stages

Signs and symptoms

The symptoms of testicular cancer include:

• A painless lump or swelling in a testicle;
• A heavy-feeling scrotum;
• A hard, rough-textured feeling of a testicle;
• Ache in the affected testicle, or lower abdomen, and;
• Enlargement or tenderness of the breast tissue.

Although most lumps found in the testicles are not cancerous, you should see your doctor if you notice any of the above symptoms.

Methods for diagnosis

Physical examination and medical history

Your doctor may take a thorough medical history and perform a physical exam. This would likely include examining the testes and the abdomen for any abnormalities.

Laboratory tests

Tumour marker test

Testicular cancers can produce specific hormones, such as human chorionic gonadotropin (hCG) or alpha-fetoprotein (AFP). Blood tests, known as tumour markers, can measure these hormones, and if found to be elevated, can suggest the presence of testicular cancers. These tumour markers are produced by certain types of testicular cancers, but can also occur with other conditions, such as liver disease.

Scans

Scans can more accurately suggest the presence of testicular cancers. These include:

• Ultrasound, which uses soundwaves to create an image of the testes and nearby structures;
• Computerised tomography (CT) scan, which uses X-rays to develop a 3D image of the body;
• Magnetic resonance imaging (MRI), which is like a CT scan, but uses magnetism instead of X-rays, and;
• Positron emission tomography (PET), in which an injection with a radioactive label is administered, then images are captured using a nuclear medicine scanner. When combined with a CT scan, it produces more detailed internal images.

Procedures

Biopsy

The surgical removal of the suspected testicle is the only accurate way of diagnosing testicular cancer. Unlikely other cancers, a biopsy of only a small sample of tissue is not appropriate, as it increases the likelihood of spreading the cancer elsewhere.

The removal of the testicle is generally performed only if your doctor is very suspicious that you may have a cancer, based on the above diagnostic tests.

Types of treatment

Surgery

Surgery involves the removal of the affected testicle (orchidectomy). This is performed by a surgeon, generally under general anaesthesia, in a hospital. An incision is made in the groin (medically known as inguinal orchidectomy), rather than directly through the scrotum, to prevent the inadvertent spread of the cancer. The whole testicle and the spermatic cord are removed through the groin. This is then sent to the laboratory for diagnosis. The surgical site is thoroughly rinsed with sterile solution, then the wound stitched up and a dressing applied.

If the cancer has not spread outside the testicle, then surgical removal of the testicle is sufficient. If the cancer has spread, then additional therapies, described below, may be needed.

Adjuvant therapy

Adjuvant therapy is given after surgery, with the aim of preventing the cancer from returning. It can take the form of radiotherapy and/or chemotherapy.

Neoadjuvant therapy

Like adjuvant therapy, neoadjuvant therapy also uses one or more of radiotherapy and chemotherapy, but is provided before surgery. This is not frequently used for testicular cancers.

Chemotherapy

Chemotherapy works by attacking cells, including cancer cells, and stopping their reproduction. Various medications are used, which can be administered intravenously or orally. They are often given in cycles, followed by rest periods, which help to reduce the toxic side effects of chemotherapy. Your doctor will monitor your dosage and treatment schedule to ensure an optimal therapeutic dosage is administered, with minimum side effects.

Chemotherapy is used to stop the growth of cancerous cells. 

Radiotherapy

In this type of therapy, focused X-rays are applied to the area where the cancer is located. Radiotherapy is commonly used in addition to surgery and/or chemotherapy. It may be used to treat men with seminoma cancers, but not for non-seminoma cancers.

Other therapies

Some people diagnosed with cancer seek out complementary and alternative therapies. None of these alternative therapies have been proven to cure cancer, but some can help people feel better when used together with conventional medical treatment. It is important to discuss any alternative treatments with your doctor before starting them.

Potential complications

Treatment side effects

Side effects of treatment for testicular cancer can include the following:

• Sterility (infertility) due to chemotherapy treatment and erectile dysfunction due to radiation treatment;
• Nausea, vomiting and fatigue from chemotherapy. Whether or not the treatment makes you feel sick is not an indication of how well the treatment is working;
• Altered bowel habits - constipation or diarrhoea;
• Joint and muscle pain can occur after a treatment session and can last a few days;
• Temporary hair loss from the head and body can result from chemotherapy. The hair will generally grow back after the treatment has ended, and;
• Tingling in the hands and feet - some chemotherapeutic agents can affect the nerves. It is important to tell your doctor if you develop these symptoms.

Advanced testicular cancer

The cancer can spread to other parts of the body through the bloodstream and lymphatic system. The cancer can then have a destructive effect on the affected organs.

Prognosis

Prognosis varies according to the type and stage of the cancer, but it is generally very good. In Australia, as of 2010, the overall five-year survival rate for testicular cancer at the point of diagnosis is 98%. For those who survive the first year, the survival rate increases to 99%. At 10 years after diagnosis, the five-year survival rate is 100%, meaning those who survived that long after diagnosis have the same odds of survival as the general population.

It is important to remember survival rates are only an indication, and are based upon the averages of previously treated patients. It is not an absolute prognosis for an individual. It is often difficult to accurately predict an individual's cure or survival rate. However, constant advances in treatment are continually improving these statistics.

Prevention

Testicular cancer cannot be prevented. Also, there are no routine screening tests for testicular cancer. Regular self-examination of the testes and getting acquainted with the way they normally feel may help you to detect any changes. However, self-examination has not conclusively been proven to detect cancers early or improve outcomes. If any abnormalities are detected, it is best to promptly see your doctor.