Endocrine Abstracts

Introduction: Survivors of childhood, adolescent or young adult cancers are at risk of endocrine dysfunction from their tumours, surgery, chemotherapy and/or radiotherapy treatment. The hypothalamic pituitary axes and gonads are at risk of dysfunction depending on a number of risk factors. Endocrine dysfunction can occur from before diagnosis of cancer, soon after but mostly a number of years later, even after survivors have been discharged from oncology follow-up. We aim to evaluate the burden of endocrinopathies and tempo of hormonal losses during long-term follow-up in survivors.

Methods: All patients currently attending our Late Effects Endocrine Clinic (LEEC) were included and following data extracted from notes: demographics, primary tumour, cancer therapy received, endocrinopathies along with year of diagnosis.

Results: 137 patients are currently under long-term follow-up in LEEC, with a F:M of 1:2. 75% of patients had previous solid intracranial tumours and 15% suffered from haematological malignancies. Mean age at diagnosis of cancer was 17 years with 80% diagnosed before 20 years of age. Mean duration of follow-up is 18 years. Treatment modalities for cancer included surgery (50%), cranial radiotherapy (85%), spinal radiotherapy (25%) and chemotherapy (60%). 7% of patients had four anterior pituitary hormone deficiencies (thyroid, steroid, gonadal and growth hormone). 70% of patients had up to 3 hormone deficiencies and 23% had none. Notably 36% of eugonadal patients had steroid and/or adrenal deficiency. Overall hormonal losses mostly occur between 6 and 15 years post cancer treatment. Adrenal deficiency occurred mostly soon after cancer treatment with no further loss after 10 years of follow-up. Thyroid deficiency occurs progressively during the first 15 years of follow-up. In contrast, gonadal hormones were progressively loss throughout the 30 years of follow-up available.

Conclusion: Gonadotrophin-sparing pituitary deficiency is not infrequent in our LEEC cohort. Tempo of hormonal losses suggest that surveillance for steroid and thyroid axes can be stopped after 15 years but surveillance for gonadal axis should continue beyond 20 years.