It’s Movember! Movember was founded to improve awareness of men’s health worldwide, particularly around prostate cancer, testicular cancer and mental health.
Today, we’re focusing on testicular cancer.
What is testicular cancer?
As the name suggests, testicular cancer refers to cancers that start in the testicles. Testicular cancers can spread to other parts of the body, so early diagnosis and treatment is key.
Testicular cancer accounts for around 1% of all cancers in men and is the most common cancer to affect those between aged 15 and 49, although it can affect men at any age. The prognosis for men diagnosed with testicular cancer is usually positive because of the availability of effective treatment: approximately 95% of men with testicular cancer will survive for 5 or more years after diagnosis, and approximately 90% will survive for 10 or more years after diagnosis.
Are there different types of testicular cancer?
There are two main types of primary testicular cancer — germ cell tumours and sex cord-gonadal stromal tumours. It is also possible for cancer from other parts of the body to spread (metastasise) to the testicles. These cancers are named and treated based on the site of the original tumour and are referred to as secondary testicular tumours. The most common type of secondary testicular tumour is lymphoma, which accounts for about 10% of testicular malignancies.
Germ cell tumours
Around 90–95% of primary testicular cancers are germ cell tumours, meaning that they originate from the cells that make sperm. Germ cell tumours can be further divided into two main types, seminomas and non‑seminomas.
Seminomas
Seminomas make up about 50% of germ cell tumours, and tend to grow and spread more slowly than non-seminomas. They are further split into two subtypes:
- Classical seminomas account for more than 95% of seminomas, and mostly affect men aged 25–50 years
- Spermatocytic seminomas are a rare type of seminoma, usually seen in men aged 55–65 years
Non-seminomas
There are four subtypes of non-seminomas. Most non-seminomas are a mix of the types listed below, and can also include some seminoma cells.
- Embryonal carcinoma is the most common non-seminoma, found in about 40% of testicular tumours, and usually grows and spreads quickly
- Yolk sac carcinoma (also known as yolk sac tumour, endothermal sinus tumour, infantile embryonal carcinoma or orchidoblastoma) is the most common form of childhood testicular cancer, although it can occur in adults
- Choriocarcinoma is a rare tumour that is fast-growing and spreads quickly to other parts of the body, such as the brain; it mainly occurs in adults
- Teratomas are usually seen in mixed germ cell tumours, and come in three main types:
- Mature teratomas are usually benign and do not spread often
- Immature teratomas are more likely to grow and spread
- Teratomas with somatic type malignancy are rare, and include areas that look like mature teratomas and areas where the cells have become a type of cancer that normally occurs in other body parts
Sex cord-gonadal stromal tumours
Gonadal stromal tumours start in the stroma, which are the supportive and hormone-producing tissues around the testicles. They are most common in children, where they account for up to 20% of primary testicular tumours, versus less than 5% of primary testicular tumours in adults. Most gonadal stromal tumours are benign, but sometimes spread. Metastatic stromal tumours don’t respond well to chemotherapy or radiation therapy. There are two main types:
- Leydig cell tumours form from Leydig cells, which produce male sex hormones
- Sertoli cell tumours originate from the Sertoli cells that support and nourish the sperm-making cells
What are the symptoms of testicular cancer?
The most common symptoms are a lump or swelling in one of the testicles, as well as changes to the shape and texture of the testicles. That means that it’s important to carry out regular (e.g. monthly) self-examinations to check your testicles, and speak to your doctor about any lumps or changes.
Other possible symptoms include a sharp pain or dull ache in the testicles, flank or lower back, which may come and go; a feeling of heaviness in the scrotum; or a change to the firmness of a testicle.
How is testicular cancer diagnosed?
A range of factors are included when making a diagnosis of testicular cancer, including patient history, imaging results and, if necessary, pathological examination of the tumour.
Patient history
A doctor will review the patient’s history to look for any risk factors that make testicular cancer more likely. These include:
- Undescended testicles (cryptorchidism)
- A close family history of testicular cancer — if your father has had testicular cancer, you are four times more likely to have it; if your brother had testicular cancer, your risk is increased by eight times
- Previous testicular cancer — patients with testicular cancer in one testicle are 12–18 times more likely to develop it in their other testicle as well
- Carcinoma in situ (CIS), also known as intratubular germ cell neoplasia. CIS is a non-invasive form of testicular germ cell tumours that is hard to detect, as there are no lumps to be found. Most commonly, it is found during a biopsy for other reasons (such as fertility problems). For around 50% of men with CIS, it develops into testicular cancer.
Diagnostic tools
Ultrasound
A scrotal ultrasound can show whether a lump is solid or filled with fluid, which can help determine if a tumour is malignant or benign.
Blood tests
Some, but not all, types of testicular cancer cause the levels of tumour marker proteins in your blood to increase, which can be detected by a blood test. These markers include:
- Human chorionic gonadotropin (HCG) – indicative of some seminomas and some non-seminomas like embryonal carcinoma and choriocarcinoma
- Alpha-fetoprotein (AFP) – indicative of non-seminomas like embryonal carcinoma and yolk sac carcinoma, but not pure seminomas
Blood tests can also detect increased levels of the enzyme lactate dehydrogenase (LDH), which can indicate how active and widespread a cancer is; however, it’s not a specific marker for testicular cancer and can result from other conditions.
Gonadal stromal tumours (Leydig and Sertoli tumours) can’t be detected using these blood markers.
Other imaging tests
To check if testicular cancer has spread, other tests such as chest x-rays, full body computed tomography (CT) scans and magnetic resonance imaging (MRI) scans may be used.
Pathologist examination
The only definitive way to diagnose testicular cancer is for a pathologist to examine the tumour under a microscope. If a testicular cancer diagnosis is suspected, the recommended approach is to remove the affected testicle and review the histology of the whole tissue afterwards, to reduce the risk of the cancer spreading.
Stages of testicular cancer
The tumour stage is a description of the progression of the cancer in terms of the size of the primary tumour, and whether it has spread to nearby lymph nodes or distant sites. There are two main staging systems used for staging testicular cancer.
The first is a three-stage system based on degree of spread and blood marker levels. This system is commonly used in the UK:
- Stage 1 – the cancer is contained within the testicle
- Stage 2 – the cancer has spread into nearby lymph nodes in the pelvis and stomach
- Stage 3 is split into three sub-stages:
- Stage 3A – the cancer has spread into distant lymph nodes (such as near collarbone) or the lungs. Marker levels are normal or slightly raised
- Stage 3B has two forms:
- The cancer has spread to nearby lymph nodes and there are higher marker levels, OR
- The cancer has spread to distant lymph nodes or to the lungs, and there are higher marker levels
- Stage 3C – either the same cancer spread as 3B but there are very high marker levels, or the cancer has spread into another of the organs (such as liver or brain)
The second way of staging is the TNM staging system, which is commonly used in the USA.
- T indicates the tumour size
- The range is TX, T0, TIS, T1, T2, T2, T3, T4
- N indicates whether the cancer has spread to nearby lymph nodes
- The range is NX, N0, N1, N2, N3
- M indicates whether the cancer has spread to other parts of the body (metastasis)
- The range is MX, M0, M1a, M1b
- S indicates the serum levels of the tumour marker proteins in the blood
- The range is SX, S0, S1, S2+, S3+
How is testicular cancer treated?
Treatment depends on the type of testicular cancer and the stage of progression.
The first option is usually surgical removal of the affected testicle (orchidectomy). This normally does not impact sexual or reproductive function. The removed testicle is examined by a pathologist to confirm the diagnosis and type of testicular cancer.
To reduce the risk of recurrence and treat any remaining cancerous tissue after surgery, chemotherapy or radiotherapy may be recommended. If the cancer has metastasised to other parts of the body, further treatments may be needed.
All types of testicular cancer increase the risk of further testicular cancer, so follow-up appointments are required to catch any reoccurrence early.
To hear about testicular cancer from a patient’s perspective, take a look at José’s story:
To find out more about testicular cancer, check out these resources:
https://www.cancerresearchuk.org/about-cancer/testicular-cancer
https://www.nhs.uk/conditions/testicular-cancer/
