Testicular germ cell tumours

Testicular germ cell cancer is mainly a disease of young men

• 85% of cases are between the ages of 15 and 44 years (1)
• life-time risk is around 1 in 200 in the UK (1)
• If diagnosed early, 95% of cases can be cured and treatment can be less intensive (1)
• between 90% and 95% of testicular cancers are germ cell tumours (GCTs) (2)
• mean age at diagnosis for testicular cancer is 33 years (2)

Germ cell tumours are broadly divided into:

• pure seminomas,
  • account for approximately 40% of tumours
• non-seminomas
  • account for approximately 60% of tumours
  • include multiple cell types - e.g. embryonal cell carcinoma, choriocarcinoma, yolk sac tumour
  • clinically more aggressive (3)

Risk factors for testicular germ cell tumours include (2):

• cryptorchidism
• family history of testicular cancer
• gonadal dysgenesis
• infertility
• cannabis use
• genetic conditions such as Klinefelter syndrome

Initial presentation (4):

• for about 90% of patients, a painless lump in the testicle is the initial symptom of testicular cancer
  • about 10% have acute pain in the testicle due to rapid tumour growth
• testicular cancer spreads to retroperitoneal lymph nodes (behind the abdominal cavity) in 10% to 20% of patients and can cause side or back pain; nausea, bloating, or constipation; and enlarged veins in the scrotum
• testicular cancer that spreads to the lungs can cause breathlessness, cough, chest pain, or haemoptysis
• in about 2% of people with testicular cancer, breast enlargement occurs

Stage of germ cell testicular tumours at diagnosis (2):

• stage I (localised to the testicle) in 70% to 75% of patients
• stage II (metastatic only to the retroperitoneal lymph nodes) in 20%
• stage III (widely metastatic) in 10%.

Management principles:

• early diagnosis and treatment, starting with a radical inguinal orchiectomy, are important in optimising outcomes
• treatment is guided by histology, clinical staging, and risk classification

Prognosis

• 5-year survival rates are 99%, 92%, and 85% for stages I, II, and III, respectively (2)

References:

1. Horwich A et al. Testicular germ cell tumour. BMJ. 2013;347:6205.
2. Singla N, Bagrodia A, Baraban E, Fankhauser CD, Ged YMA. Testicular Germ Cell Tumors: A Review. JAMA. Published online February 03, 2025.
3. Sohaib SA, Koh DM, Husband JE. The role of imaging in the diagnosis, staging, and management of testicular cancer. AJR Am J Roentgenol. 2008;191(2):387-95.
4. Voelker R. What Are Testicular Germ Cell Tumors? JAMA. Published online May 29, 2025.