LGG-42. BEVACIZUMAB-ASSOCIATED SECONDARY AMENORRHEA AND PREMATURE OVARIAN FAILURE IN ADOLESCENT FEMALE PATIENTS WITH LOW-GRADE CNS DISEASE

Compelling body of evidence exists to use bevacizumab, a humanized monoclonal anti-VEGF antibody, in selected paediatric patients with low-grade CNS tumours. Common toxicities of bevacizumab, hypertension, proteinuria, epistaxis, mucosal perforation, decreased wound healing are well reported. However, the effect of bevacizumab on female ovarian function and long-term fertility is still being documented. Current evidence for bevacizumab-associated decline in ovarian function is largely from breast and colon cancer cohorts where exposure to multimodal chemotherapy confounds causative relationships. Fertility counseling and oocyte cryopreservation is currently offered as standard of care to post-pubertal females at high risk of infertility due to high-dose radiation and chemotherapy. Adolescent females with low-grade CNS tumours on bevacizumab represent a unique population which could potentially be at high risk for infertility. We report 2 cases of adolescent girls treated with bevacizumab as a single agent and in combination with vinblastine for NF2-associated vestibular schwannomas and brainstem glioma respectively. Both patients were post-pubertal with established menstrual cycles and normal baseline FSH/LH/oestradiol/AMH values prior to commencement of therapy. They became amenorrhoeic shortly after starting of therapy with levels of FSH/LH/oestradiol suggestive of premature ovarian failure. One patient has remained asymptomatic, whereas the other has developed profound post-menopausal symptoms interfering with quality of life which necessitated commencement of hormone-replacement therapy. Appropriate pretreatment fertility investigation and consultation should be offered to all post-pubertal females starting on bevacizumab. Further research into the long-term effects of gonadal toxicity in both females and males with drugs inhibiting angiogenesis is needed.