ESPE Yearbook of Paediatric Endocrinology

Brief Summary: This retrospective cohort study included 54 pre- or peri-pubertal boys affected by hematological cancer who underwent a testicular biopsy for fertility preservation at the time of diagnosis, before any gonadotoxic treatment. The presence of cancer cells in immature testicular tissue of young boys was assessed by histology, immunohistochemistry (IHC) and PCR at the time of cryopreservation, before treatment. Contamination by cancerous cells was found in 10/28 boys using IHC, with a higher rate in patients with acute lymphoblastic leukemia, compared to those affected by lymphoma. PCR showed contamination in 3/15 patients who had specific bone marrow rearrangements at the time of diagnosis. Mean spermatogonial number was decreased in patients of all age groups when compared to healthy reference cohorts.

In past decades, the prepubertal testis was considered a preferential site for leukemia and lymphoma relapse. Testicular biopsy was used to assess the presence of residual cancer cells, as an indicator of treatment effectiveness and recurrence risk. Tissue fragments were analysed with histology and immunohistochemistry and cancer cell contamination ranged from 15% to 45%. The results of these analyses indicated the spreading potential of cancer cells and their ability to persist in the testis after treatment. However, it is not directly comparable with assessment of cancer cell contamination of cryopreserved testicular tissue taken for fertility preservation.

This is the first study to demonstrate a high risk of contamination by cancer cells in immature tissue collected before any therapy and analyzed with modern techniques. In clinical practice, it is essential to identify patients who might benefit from the cryopreservation without relapse risk. The risks of contamination have led many groups to collect immature testicular tissue after the first cycles of chemotherapy, as in prepubertal and adult females this modality is shown to reduce ovarian tissue contamination by cancer cells, without altering fertility potential.

Reference: 1. Kourta D, Kanbar M, Amorim CA, Wyns C. Cancer cell contamination and decontamination methods for ovaries and testes: special focus on prepubertal gonads with a view to safe fertility restoration. Hum Reprod 2023; 38:780–798.