Long-term effects on fertility after central nervous system cancer: A systematic review and meta-analysis

Background Central nervous system (CNS) cancer represents a common group of solid tumors in childhood and young adults, and less frequently in adults aged 30-40. Due to treatment advancements with increasing survival rates, disorders of the hypothalamus-pituitary axis have become increasingly relevant for patients' future fertility plans. Most guidelines recommend that physicians should counsel their patients about fertility prognosis before initiating gonadotoxic therapy. However, for fertility preservation measures, gonadal toxicity as the only relevant risk factor has not yet been systematically reviewed.Methods A systematic literature search was performed in MEDLINE, Embase, and Cochrane in January 2024. The systematic review included studies of patients who had undergone treatment for all types of malignant CNS cancer. The outcomes were defined as clinically relevant gonadal toxicity as well as preserved fertility. The study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.Results The qualitative analysis included 31 studies with a total of 4590 patients after CNS cancer. The overall pooled prevalence of gonadal toxicity was found to be 20% (95% confidence intervals [CI]: 10%-34%). Preserved fertility was present in 75% (95% CI: 64%-83%) of the patients and was maintained after at least 5 years following treatment (75%, 95% CI: 46%-91%).Conclusions This initial meta-analysis provides a basis for fertility counseling after diverse CNS cancer treatments. Due to the high heterogeneity of the study population and lack of individual patient data on fertility outcomes, it is not possible to provide an exact estimation of the fertility prognosis following a specific treatment. Thus, fertility preservation measures should still be recommended.