Sperm DNA integrity in testicular cancer patients

We evaluated the impact of testicular germ cell cancer (TGCC), its treatment and length of follow-up on sperm DNA integrity.

In 96 TGCC patients, semen was collected at specific intervals until 5 years after treatment. Sperm DNA integrity was assessed by the sperm chromatin structure assay (SCSA, n = 193) and by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL, n = 159) assay. Results were expressed as DNA fragmentation index (DFI). Controls comprised of 278 military conscripts.

Post-surgery testicular cancer (TC) patients did not differ from controls. Compared with pretreatment values, radiotherapy induced a transient increase in SCSA(DFI) (medians: 12 versus 19%; P = 0.03), normalizing after 3-5 years. One year or more after therapy, 5/13 (38%) of normozoospermic, irradiated patients had SCSA(DFI) >27% compared with 7% of normozoospermic controls (P = 0.002). More than two cycles of chemotherapy decreased DFI 3-5 years post-therapy (median SCSA(DFI): 12 versus 9.1%, P = 0.02; median TUNEL(DFI): 11 versus 7.5%, P = 0.03).

Irradiation increases sperm DNA damage 1-2 years after treatment, and 38% of irradiated patients with normozoospermia had high (>27%) DNA damage, which may affect the sperm-fertilizing ability. TC per se is not associated with an increase of DFI, and DFI is reduced by three or more cycles of chemotherapy.