Testis cancer represents 1% of all male cancers. As the second most common cancer in young men aged 18 to 39 years, over 700 new cases will be diagnosed in Australia each year.
The majority of testis cancers (90-95%) arise from germ cells, the cells from which the sperm develop. Tumours can also arise from structural and supporting cells within the testis, or rarely as spread of lymphoma.
We classify germ cell tumours as either seminoma or non-seminoma. Seminoma makes up 65% of cases and typically occurs in men aged 30 to 50. It is sensitive to both radiotherapy and chemotherapy. Non-seminoma is more common in younger men, aged 20 to 35. Most subtypes of non-seminoma are sensitive to chemotherapy but not radiotherapy. One type of non-seminoma, called teratoma, is resistant to chemotherapy and must be removed surgically.
What are the symptoms of testis cancer?
Men with a testis cancer may notice a painless mass or swelling in the testis. Only one in ten men will experience pain in the testis from cancer. About 5-10% of men present with fluid around the testis, called a hydrocele.
Some men may notice enlargement or tenderness in the breast tissue, due to hormones released by cancer cells.
Back pain can occur if the cancer has spread outside the testis to the lymph glands on the back wall of the abdomen. This area is called the retroperitoneum.
What are the risk factors for testis cancer?
- A family history of testis cancer in the father or brother
- A prior history of cancer in the other testis
- As a child, having a testis that did not descend into the scrotum from where it usually develops inside the abdomen
- Sub-fertilility, which is associated with a three times greater risk of testis cancer than the general population
- Caucasian race
- HIV infection
Diagnosis and staging
A patient with suspected testis cancer should have an ultrasound of the scrotum to confirm the diagnosis. In most cases the patient will require an operation to remove the testis. Unlike other cancers, where a diagnosis can be reached by removing a small piece of tissue (called a biopsy), testis cancer can spread to other parts of the body if a cut is made into it. Therefore the entire testis must be removed.
If testis cancer is confirmed, a CT scan of the chest, abdomen and pelvis will help determine whether and how far the cancer has spread. Sometimes a brain CT or MRI is also required, depending on the patient’s symptoms and the specific subtype of cancer.
Prior to removal of the testis, blood tests are taken for specific tumour markers (alpha-fetoprotein, beta human chorionic gonadotrophin and lactate dehydrogenase). These chemicals can be elevated in men with testis cancer, and persistence of these markers after treatment suggests the presence of cancer in other parts of the body.
How is testis cancer treated?
Treatment of testis cancer depends on its stage. Stage 1 cancers are confined to the testis and, in these cases, removal of the testis may be the only treatment needed. Such an approach, however, requires strict and intensive follow-up to detect and treat any cancer recurrence. Another option is to give a small dose of chemotherapy to reduce the risk of recurrence, however this approach has side effects including the risk of infertility. All patients should undergo sperm banking prior to starting chemotherapy.
Stage 2 cancers have spread to the lymph glands in the abdomen or pelvis. Depending on the type of cancer, these patients will require either radiotherapy or chemotherapy. If cancer is still present after a full course of treatment, major surgery will be required to remove it.
Chemotherapy is also used for Stage 3 cancers, where the cancer has spread beyond the lymph nodes to other areas of the body such as the lungs and liver. Again, surgery may be required after chemotherapy to remove residual disease.