Abstract
BACKGROUND: Many cancer treatment methods can affect fertility by damaging the reproductive organs and glands that control fertility. Changes can be temporary or permanent. In order to preserve the fertility of cancer patients and protect the genital organs against gonadotoxicity, methods of fertility preservation are increasingly used. Considering that some patients ultimately decide not to use cryopreserved reproductive material, this review analysed the percentage of post-cancer patients using cryopreserved reproductive material, collected before treatment as part of fertility preservation. METHODS: A systematic search of studies was carried out in accordance with the Cochrane Collaboration guidelines, based on a previously prepared research protocol. The search was conducted in Medline (via PubMed), Embase (via OVID), and the Cochrane Library. In addition, a manual search was performed for recommendations/clinical practice guidelines regarding fertility preservation in cancer patients. RESULTS: Twenty-six studies met the inclusion criteria. The studies included in the review discussed the results of cryopreservation of oocytes, embryos, ovarian tissue, and semen. In 10 studies, the usage rate of cryopreserved semen ranged from 2.6% to 21.5%. In the case of cryopreserved female reproductive material, the return/usage rate ranged from 3.1% to 8.7% for oocytes, approx. 9% to 22.4% for embryos, and 6.9% to 30.3% for ovarian tissue. In studies analysing patients' decisions about unused reproductive material, continuation of material storage was most often indicated. Recovering fertility or death of the patient were the main reasons for rejecting cryopreserved semen in the case of men. CONCLUSION: Fertility preservation before gonadotoxic treatment is widely recommended and increasingly used in cancer patients. The usage rate is an important indicator for monitoring the efficacy of these methods. In all of the methods described in the literature, this indicator did not exceed 31%. It is necessary to create legal and organizational solutions regulating material collection and storage and to create clear paths for its usage in the future, including by other recipients.