Formerly known as intratubular germ cell neoplasia (ITGCN) or carcinoma in situ.
Most malignancy post-pubertal GCTs originate from GCNIS (pre-pubertal yolk sac and teratomas, and spermatocytic tumours do not).
GCNIS is a common finding in testes removed with for germ cell tumour (?present in 80 – 90 % invasive testis cancer)
Risk of contra-lateral GCNIS is about 10 % (higher risk if atrophic testis and/or cryptorchidism).
The 5 year risk of developing testicular cancer in a testis with GCNIS is about 50 % (and 70 % at 7 years)
The only way GCNIS can be diagnosed is histologically on a biopsy (does not raise markers).
- 2 x different biopsy sites, aiming for 3 x 3 mm cubes, preferably in Bouin’s solution not formalin
It is unclear if treating GCNIS improves survival, but treatment is offered based on the high progression rate to testicular cancer.
Treatment options include:
- Surveillance
- Regular self-exam, clinician exam, and ultrasound
- Radiation
- 20 Gy in 10 fractions
- Curative
- Will reduce androgen and sperm production
- Chemo
- Dose dependent cure rates – reportedly cures 2/3
- Associated systemic effects make it reasonably unattractive
- Surgery
- Curative – but obvious downsides esp if single testis
Who should be biopsied looking for GCNIS?
- Controversial
- EAU – “discuss biopsy of contralateral testis with those at high risk for GCNIS” (atrophic testis, history of cryptorchidism)
- Morbidity of treatment of GCNIS needs to be considered, and biopsy itself is not without potential complication in single testis