What Is a Germ Cell Tumour and How Does It Spread?

Germ Cell Cancer Explained: Metastatic Risks & Therapies

Metastatic germ cell tumour is a form of cancer that begins in your body's reproductive cells, known as germ cells, and spreads to other areas. The word 'metastatic' refers to tumours spreading beyond their original site. These tumours usually develop in the testes or ovaries but may also appear in parts like your chest, abdomen, or brain. Let us discuss its causes, types and treatment options.

What is a Germ Cell Tumour?

‘Germ’ refers to ‘germinal’ meaning these are the cells that give rise to gametes (sperm and eggs). These cells mature into eggs in females and sperm in males. A germ cell tumour refers to a collection of reproductive cells which can be benign or malignant. Malignant germ cell tumours are cancerous and spread to other parts of the body.

This condition is more common in men between the ages of 15 and 35, although women can also be affected.

How Do Metastatic Germ Cell Tumours Spread?

Germ cells are responsible for producing sperm in men and eggs in women. When these cells become cancerous, they may grow uncontrollably, forming a tumour. In some cases, the cancer spreads through your bloodstream or lymphatic system to distant organs.

For instance, a testicular germ cell tumour may spread to your lungs, liver, or brain. However, these can also form in your chest or other parts where germ cells are present.

What are the Types of Germ Cell Tumours?

You will find that germ cell tumours are mainly divided into two types:

• Seminomas: These usually grow slowly and tend to respond well to treatment.
• Non-seminomas: These grow faster and are more likely to spread early. They are aggressive and may include yolk sac tumours, embryonal carcinoma, choriocarcinoma, or teratoma.
   

Both types have the potential to become metastatic, but non-seminomas are usually at a higher risk.

What are the symptoms of metastatic germ cell tumours?

Metastatic germ cell tumours can cause various symptoms depending on their location. These include:

• A painless lump or swelling in the testicle or lower abdomen
• Pain or heaviness in the scrotum or pelvic area
• Problem passing stool
• Chest pain or breathing difficulty if the lungs are involved
• Abdominal pain
• Fatigue or weight loss
• Headaches, seizures, or other neurological issues occur if the brain is affected.
   

How do doctors diagnose metastatic germ cell tumours?

Your doctor will conduct a physical exam and use a range of tests to confirm the diagnosis. These typically include:

• Ultrasound or CT scans to locate the tumour
• Blood tests for tumour markers like AFP (alpha-fetoprotein), hCG (human chorionic gonadotropin), and LDH (lactate dehydrogenase)
• Biopsy to identify the type of cancer cells
   

Once confirmed, your healthcare provider will inform you of the stage of your tumour. It entails understanding how far the tumour has spread and planning the most effective treatment.

What are the treatment options for metastatic germ cell tumours?

Your doctor will treat you based on the stage, type and location of the cancer. Some common treatment options include:

• Surgical Intervention: Doctors usually recommend surgery to eliminate the tumour. This may include ovarian cystectomy or salpingo-oophorectomy. For men, doctors usually remove the testicle along with the tumour.
• Chemotherapy: The treatment sequence depends on the stage. For metastatic disease, chemotherapy is often the first treatment to shrink tumours throughout the body. Surgery is then used afterward to remove any remaining cancer cells.
• Radiation Therapy: It destroys cancer cells by using high-energy X-rays. Seminomas are very sensitive to radiation therapy, which can be an effective treatment for early-stage disease. Non-seminomatous tumours are primarily treated with chemotherapy, as they are less responsive to radiation.
   

Metastatic germ cell tumours have among the highest cure rates of any solid cancer. Survival rates are excellent, especially for good-prognosis groups, where cure rates exceed 90%. Even in poor-prognosis groups, modern chemotherapy regimens can cure approximately half of all patients.