Contents
Introduction
Testicular cancers are usually germ cell tumours (>95%). There are two main types (these account for 80% of all tumours):
- Seminoma (dysgerminoma in women). These arise from the seminiferous tubules. They are a low-grade tumour and metastasis can occur via lymphatics and to the lungs.
- Teratoma. A teratoma has a mixture of both mature and immature cells. Initially, these arise from germ cells, and often contain muscle, bone, fat and a variety of all sorts of other tissue. They are classified according to the degree of differentiation. As always, well-differentiated tumours have the best prognosis.
More recent classification systems divide tumours into Seminoma (about 50%) and Non-Seminoma germ cell tumours (also about 50%) – which includes teratomas.
Occasionally both types of tumour occur together.
Rarely, germ cell tumours can occur at extragonadal sites. They generally occur along the midline in the mediastinum, pituitary and retroperitoneum. These tumours should be treated in the same way.
Testicular cancers can secrete tumour markers which provide a good way to diagnose the condition.
Of all the urological tumours – testicular cancer is the most quickly progressing.
The prognosis for testicular cancer is generally good – with >95% survival rates. Testicular cancers are typically treated with chemotherapy.
Epidemiology
- Testicular cancers account for 1-2% of all tumours
- The incidence is very low, with prevalence being about 5 per 100 000
- They are the most common cancer in men ages 15-35
- Can occur at any age but most commonly between 15 and 40
- Ovarian cell cancers are far less common than testicular cancers
- Teratomas tend to occur in younger populations than seminomas
- Incidence of testicular cancer is much higher in developed countries – for example:
- Norway – 12 per 100 000
- India – 0.5 per 100 000
Risk factors
- Cryptorchidism (failure of testes to descend)
- Klinefelter’s syndrome
- Male infertility
- 3x increased risk
- Low birth weight
- Infantile hernia
- Height – taller men are at greater risk
- Previous testicular cancer (in contralateral testes)
- Family history
- 50x increased risk in carriers of the TGCT1 gene
- Carried by 20% of the population
Presentation
95% of cases of testicular cancer will present as a firm lump on the testes. It may or may not be painful, but is usually painless.
- This lump will feel like it is “stuck on” to the side of the testes and may have concerning tumour-like characteristics – craggy, feels rock hard.
- A globally swollen and / or tender testes is much less likely to be testicular cancer. Consider epididymo-orchitis, epididymal cyst, hydrocoele or varicocoele, or hernia.
- Some patients complain of a testicular “ache” or abdominal pain
- There may be a sensation of “dragging” or “anchoring” in the scrotum
- Hydrocoele
- Gynaecomastia – due to beta-hCG production by the tumour
- Metastasis – there may be some evidence of spread to para-aortic lymph nodes with associated back pain.
Differentials
- Hernia
- Epididymo-orchitis
- Testicular torsion
- Hydrocoele
- Varicocoele
- Epididymal cyst
- Infection
Testicular Pain
Testicular pain should be considered to be testicular torsion until proven otherwise!
- Torted testes are more likely in a young patient
- Epididymitits or epididymo-orchitis is more likely in an older (>35) patient.
- Always seek urgent (i.e. emergency) urological review of testicular pain – i.e. referer to the emergency department for urological review
Investigation
If testicular cancer is suspected on the basis of history and examination alone then refer immediately and do not wait for investigation results.
- All suspicious testicular lumps should be examined by ultrasound. Diagnosis is often confirmed with USS.
- Thoracic-abdominal CT should be performed for staging purposes after the diagnosis is made
- Bloods can be performed for serum tumour markers:
- α-fetoprotein (AFP)
- β-human chorionic gonadotrophin(HCG)
- Lactate dehydrogenase (LDH)
- These tests are NOT diagnostic. Levels can be raised in other conditions, and normal marker levels do NOT exclude testicular cancer
- The above markers tend to be increased more with more severe disease.
- Additional CT / MRI may be performed to check for distant metastasis (particularly in the lungs, liver, and retronperitoneally)
Staging
Staged on a scale of I – IV
I – no disease outside testes
II – Local lymph node involvement
III – local and distal lymph node involvement
IV – Extralymphatic metastases
- Most commonly in the lungs and liver
Even metastatic testicular cancer can be curable and generally has a good cure rate compared to other cancers.
- 80% of seminoma are stage I at diagnosis
Management
Depends on the tumour type and the stage. Seminoma has a better prognosis than NSGCT although both have relatively good prognoses compared to other cancers.
- Radical orchidectomy (removal of the testes) is usually performed.
- The affected testis is removed – typically via the inguinal route to minimise the risk of highly malignant cells spilling into the scrotum. The testicle and spermatic cord are removed as far as the inguinal ring.
- Patients should be offered testicular prostheses.
- Chemotherapy is used to treat metastatic disease
- BEP chemotherapy is often used
- BEP – bleomycin, etoposide, cisplatin
- In those who do not require chemotherapy then surveillance should be performed to check for spread. This is often in the form of a PET and / or CT scan at regular intervals – e.g. every 3 months initially, gradually becoming less frequent. If no disease is seen at 5 years then this may be ceased
Seminoma
- Even with stage I disease, there is a 30% chance of recurrence. Adjuvant therapy decreases this to less than 5%. Chemotherapy is not associated with long-term side effects (Such as secondary malignancy) that you find in those that have been treated with radiotherapy.
- Combination chemotherapy will cure 90% of those with metastatic disease.
- 5-year survival is 90-95%
Teratoma
- Relapse is twice as likely as in Seminoma.
- About 20% of men will be infertile at the time of diagnosis, but almost all of the rest will retain fertility and be able to father children.
- 5-year survival is 60-95% depending on tumour stage and metastatic spread at the time of diagnosis.
Long-term outcomes
- Risk of reduced fertility – both as a consequence of removal of a testis and of chemotherapy
- Long-term side effects of the chemotherapy can include:
- Increased risk of other cancers
- Small intestine
- Bladder
- Kidney
- Lung
- Increased risk of cardiovascular disease
- Late relapse (>2-3 years after treatment) has a poor prognosis and tends not to respond well to chemotherapy
Screening
There is no formal screening program for testicular cancer as there is insufficient evidence to prove its benefit. However – self-examination of the testicles should be encouraged. It is advised that all men from teenagers to those over 50 should examine their testicles on a monthly basis. Any abnormality should be investigated with testicular ultrasound.
- Patients with increased risk should be advised of this increased risk and encouraged to perform regular self checks (family history, history of undescended testes, testicular atrophy)
Differentiating Teratoma and Seminoma
|
Feature
|
Teratoma
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Seminoma
|
|
Age of onset
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20-30
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30-40
|
|
αFP
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Produced
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Not produced
|
|
Β-HCG
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Produced
|
Produced
|
|
Clinical picture
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Painless, palpable, hard irregular swelling
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Painless, palpable, hard, irregular swelling
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References
- Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
- Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
- Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy
- Testicular Cancer – patient.info
- Testicular Cancer – RACGP red book guidelines