Predictive factors for the recurrence of Cushing's disease after surgical treatment in childhood.

ABSTRACT

INTRODUCTION: Cushing's disease (CD) is a rare cause of hypercortisolaemia caused by excessive adrenocorticotropic hormone (ACTH) excretion by a pituitary adenoma. Data on the predictive factors for the recurrence of the disease are limited in comparison with those for the adult population. The identification of the predictive factors for CD recurrence in patients after surgical treatment in childhood was the aim of the presented study. MATERIAL AND METHODS: A retrospective analysis of 26 CD patients, mean age at the time of diagnosis 13.46 years, treated at the Children's Memorial Health Institute (CMHI) in the years 1994-2018. Two time points were set at which the follow-up (FU) of patients was finished. The first time point (shorter FU, 24 patients) was set when the patients completed their treatment at the CMHI. The second time point (longer FU, 26 patients) was determined on the basis on the time when adult patients (previous CMHI patients) completed the author's questionnaire. In the case of the other patients (current CMHI paediatric patients and patients who did not respond to the questionnaire), the latest FU in this second time point was made during the last visit to the CMHI. The predictors of disease recurrence were evaluated by the construction of a logistic regression model and receiver operating characteristics. RESULTS: The average FU after transsphenoidal pituitary surgery (TSS) of 26 patients was 10.23 years (0.67-24.50). Recurrence of CD occurred in four out of 26 patients (15.4%) after an average time of 3.6 years (0.92-8.08) following definitive treatment. The results of the statistical analysis of potential predictive factors for CD recurrence were not conclusive, with no variables confirmed above the statistical significance threshold of p < 0.05. As regards the longer FU, two potential predictors mean cortisol level at night (p = 0.10) and max. ACTH level after ovine corticotropin-releasing hormone (oCRH) test (p = 0.10), were the closest to meeting the assumed threshold of statistical significance. CONCLUSION: Recurrence of CD may be diagnosed even a long time after its effective treatment. It is possible that cortisol levels at night and ACTH values in oCRH test before TSS may be helpful to predict which patients may experience a recurrence after successful initial treatment. However, further studies on a larger sample are needed to confirm this hypothesis.