Progression of pituitary tumours: impact of GH secretory status and long-term GH replacement therapy

Background: Most patients treated for hypothalamic–pituitary tumours develop GH deficiency. Long-term GH replacement treatment in adults with a previous history of hypothalamic–pituitary tumour could represent a concern about increasing the risk of tumour enlargement or recurrence. Purpose: To assess the progression risk of hypothalamic–pituitary tumours according to the GH secretory status (normal GH secretion, non-treated and treated GH deficiency). and determine the predictors of neoplasm recurrence. Methods: We retrospectively reviewed 309 patients with tumours of the hypothalamic–pituitary region (294 subjects underwent neurosurgery while 81 radiotherapy) who were followed for 9.9 ± 8.3 years. Results: Out of 309 patients, 200 were affected by severe GH deficiency; 90 of these underwent GH therapy. The tumour progression rate did not differ among GH-sufficient, not-treated and treated GH-deficient patients (16.5%, 16.4%. and 10.0%, respectively). In a multivariate analysis, previous radiotherapy (HR 0.12, CI 0.03–0.52, p < 0.005) and residual tumour (HR 8.20, CI 2.38–28.29, p < 0.001) were independent predictors of recurrence. After controlling for multiple covariates, the tumour recurrence risk in GH-sufficient and GH-treated patients was similar to that observed in not-treated GH-deficient patients. Conclusions: With limitations of retrospective analysis, GH therapy is not associated with an increased progression rate of tumours of the hypotalamic–pituitary region during long follow-up, thus supporting the long-term safety of GH treatment. The only predictors of tumour recurrence appear to be the presence of residual disease and the lack of radiotherapy.