By analogy with the mouse, the activity of control pathways for transposable elements (TE) in foetal primordial germinal cells could prove to be a determinant for fertility in adulthood in humans. Moreover, defects in the control of transposable elements (TE) could also contribute to the aetiology of germinal testicular cancer, by inducing chromosomal instability and tumorigenesis. In this context, the aim is to analyse a specific type of adult germinal testicular cancers, seminomas. Directly related to our research interest, the histological, transcriptomic and epigenetic features of theses adult tumours are reminiscent of germinal cells normally present in foetuses. The investigator postulates that these similarities could also extend to the biology of transposable elements (TE), and in particular to the initiation of the control of these elements. The management of seminomas requires surgery, orchiectomy, which consists of the total excision of the affected testicles. Using high-resolution high-throughput sequencing techniques, we propose to analyse the control pathways of transposable elements (TE) in tumour samples harvested from surgical pieces in comparison with adjacent healthy tissue. The results obtained in these tumour samples will be compared with those in normal foetal gonad samples.

Inclusion Criteria:

• men who have provided oral consent
• men with germinal testicular cancer with negative or low serum markers (Alpha Foeto Protein AFP and Human Chorionic Gonadotrophin hCG), indicators of a seminomatous-type tumour
• men who have undergone orchiectomy (total excision of the affected testicle)
• confirmation of the diagnosis of seminomatous or non-seminomatous type by histology of the surgical piece
• absence of hepatitis B or C or infection with human immunodeficiency virus (HIV).

Exclusion Criteria:

• men without national health insurance cover
• Adults under guardianship

men with germinal testicular cancer