Testicular cancers are malignancies that develop in one or both of the testicles. The testicles (or testes) are two egg-shaped glands of the male reproductive system that sit outside of the body in a skin sac called the scrotum.
The testicles are responsible for the production and storage of sperm, the male gamete (reproductive cell) that swims to fertilise the female gamete, called ova or eggs. They are also responsible for producing and secreting testosterone, the primary male hormonea chemical substance produced by glands in the endocrine system that regulates various functions in the body. Testosterone is responsible for the regulation of sexual development (including development of male reproductive organs, and secondary sex characteristics such as facial hair and voice deepening), bone and muscle massthe total amount of skeletal muscle tissue in the body, fat distribution, sex drive (or libido), sperm production and red bloodthe red bodily fluid that transports oxygen and other nutrients around the body cell production.
Testicular cancers are generally diagnosed in men between the ages of 25-40, however, it can affect anyone with testicles – including men, teenagers, transgender women, non-binary individuals, and intersex people – at any age.
Types of Testicular Cancers
There are several types of testicular cancers, which are categorised by the types of cellsthe basic structural and functional unit of all living things they develop from.
Seminoma – Germ Cell Tumours
Seminomas are one of the most common forms of testicular cancers. They develop from germ cellsa cell that develops into reproductive cells (eggs in females, sperm in males), which are the biological cells that develop into gametes during fetal development. In general, seminomas develop between the ages of 25-45, and are slow growing, rarely metastasise, and usually have a good prognosisto predict how a disease/condition may progress and what the outcome might be.
In some cases, seminomas can increase levels of human chorionic gonadotropin (HCG), which is a hormone produced by the placenta (an organ that develops alongside a fetus during pregnancy) during early stages of pregnancy. In men, this hormone acts similarly to the luteinising hormone (LH), which is responsible for regulating sperm production and signalling for the production of testosterone. Excess levels of these hormones can cause a variety of side effects, including fertility issues.
Non-Seminoma – Germ Cell Tumours
Non-seminoma germ-cell tumours are also a common form of testicular cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs. They often develop between their late teens and early 20’s, and often develop and metastasise more quickly than seminomas. There are four primary types of non-seminoma germ-cell tumours.
Embryonal Carcinomas
Embryonal carcinomas are a common type of testicular tumours that often develop from primordial germ cells, which are germ cells that have not yet developed into gametes. While this type of tumoura tissue mass that forms from groups of unhealthy cells can be aggressive, it often has a good prognosis.
In some cases, embryonal carcinomas can increase levels of alpha-fetoprotein (AFP), which is responsible for transporting heavy metal ions in fetal blood during early stages of pregnancy, and HCG in the blood.
Choriocarcinomas
Choriocarcinomas are rare and aggressive tumours that often develop from trophoblastic cells, which are specialised cells in the placenta. It is often fast growing, has a high metastasiswhen the cancer has spread to other parts of the body, also known as mets rate, and may be a part of a mixed germ-cell tumour. While they are aggressive, they may have a good prognosis when caught early.
In most cases, testicular choriocarcinomas increases the levels of HCG in the blood.
Endodermal Sinus Tumours
Endodermal sinus tumours, or yolk sac tumours, are the most common form of testicular cancer in children. These types of tumours develop in the lining of the yolk sac of an embryo, and often increase levels of AFP in the blood. While this type of tumour is highly aggressive, they can have a good prognosis.
Teratomas
A teratoma is a rare type of germ-cell tumour that contains bodily tissuea group of cells that work together to perform a function, such as hair, bone, muscle and teeth. They usually are non-functional (do not secrete hormones), and may be seen as part of a mixed germ-cell tumour. While it is often aggressive, it can have a good prognosis when caught early.
Teratomas can be classified based on how the cells look under the microscope:
- Mature teratoma: cells look similar to healthy tissue but contain bodily tissue that shouldn’t be present within the brain (such as skin, hair, muscle, bone, etc.). These tumours are generally benignnot cancerous, can grow but will not spread to other body parts (non-cancerous).
- Immature teratoma: cells look similar to those found in a foetus, and also have components not generally found in the brain. These tumours are generally malignantcancerous, may grow and spread to other areas of the body (cancerous), but can have a good prognosis when found early.
- Teratoma with malignant transformation: a malignant GCT transforms into a malignant non-germ cell tumour, also known as a somatic (all cells that are not germ cells) malignancy. These tumours are highly aggressive, and may not have as good of a prognosis as other GCTs.
Mixed Germ Cell Tumours
Mixed germ-cell tumours are cancers that develop from a variety of different cancerous cells. These cells can be a mix of seminoma and non-seminoma tumour cells, or cells from various non-seminoma tumours. When a mixed germ-cell tumour is found, they are often treated similarly to non-seminoma tumours due to their similar growth and metastasis rates.
Stromal Tumours
Stromal tumours are cancers that originate from the supportive hormone-producing tissues of the testicles, called the stroma. They are very rare, and develop from Sertoli and Leydig cells, which are support cells in the male reproductive system.
Sertoli-Leydig cell tumours are cancers that produces male hormones, such as testosterone. These types of tumours are often benign (non-cancerous) and slow growing, however, in rare instances they can be cancerous. Malignant (cancerous) Sertoli-Leydig cell tumours usually don’t respond well to chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells and radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells, and may have a poorer prognosis than other testicular cancers.
Intratubular Germ Cell Neoplasias (ITGCNs)
Intratubular germ-cell neoplasias (ITGCNs) is a condition where cells in the testicles look abnormal, but they haven’t spread beyond their point of origin. While this condition is not a malignancy, there is a high riskthe possibility that something bad will happen that it can transform into a form of testicular cancer. ITGCN is considered rare, and is often difficult to diagnose.
Treatment
If testicular cancer is detected, it will be staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body) and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
Cancers can be staged using the TNM staging system:
- T (tumour) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for testicular cancer may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Unilateral orchidectomyremoval of one testicle /orchiectomy.
- Bilateral orchidectomyremoval of both testicles /orchiectomy.
- Lymphadenectomysurgical removal of lymph node(s).
- Testicular prosthetic surgeryinsertion of a prosthetic testicle(s) after an orchidectomy.
- Radiation therapy.
- Chemotherapy.
- Watch and waitthe close monitoring of a cancer without giving treatment until symptoms appear or worsen (for early-stage testicular cancers or after an orchidectomyremoval of one or both testicles, also known as orchiectomy).
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Testicular Cancer Treatment and Fertility
Treatment for testicular cancer may make it difficult to conceive a child. If fertility is important to you, discuss your options with your doctor and a fertility specialist prior to the commencement of treatment.
Risk factors
While the cause of testicular cancer remains unknown, the following factors may increase the risk of developing the disease:
- Having a personal history of testicular cancer.
- Having a family history of testicular cancer.
- Being infertile.
- Having certain conditions, such as
- Human immunodeficiency virus (HIV).
- Acquired immunodeficiency syndrome (AIDS).
- Cryptorchidism (undescended testicle(s)).
- Hypospadias (penile abnormality).
- Inguinal herniathe protrusion of organs or tissue through a weakened section of the abdomen (lump in the groinarea between the abdomen and thighs – repaired or not repaired).
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
In some cases, testicular cancers appear asymptomatic.
Common symptoms of testicular cancer may include:
- A painless swelling in the testicle(s).
- A lump in the testicle(s).
- Changes in testicular size and/or shape.
- A feeling of heaviness in the scrotum.
- A feeling of unevenness in the scrotum.
- Pain or discomfort in the testicle(s) and/or scrotum.
- Fluid build-up in the scrotum.
- Aches in the lower abdomenstomach, stomach area, belly, testicle(s) and/or scrotum.
- Back pain.
- Enlargement and/or tenderness of breast tissue caused by excess hormones.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have testicular cancer, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Physical examinationan examination of your current symptoms, affected area(s) and overall medical history.
- Imagingtests that create detailed images of areas inside the body tests, most commonly an ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body .
- Blood teststesting done to measure the levels of certain substances in the blood.
- Exploratory surgeryan exploratory surgical procedure used for conditions that cannot be confirmed by scans and tests alone.
Exploratory Surgery
After conducting the previously mentioned diagnostic tests, your doctor may strongly suspect that you have a testicular cancer. In most cases, a diagnosis can be confirmed after a biopsyremoval of a section of tissue to analyse for cancer cells, where a section of tissue is removed and analysed for cancer cells. However, doctors avoid conducting a biopsy in patients who have suspected testicular cancer as there is a small risk that making an incision in the scrotum could cause cancer cells to spread. As such, the only way to confirm the diagnosis safely is to perform a unilateralaffecting one side orchidectomy.
Once the testicle has been removed, it will be sent to a laboratory and analysed for cancer cells.
