Endocrine Abstracts

Background

Acromegaly is an infrequent chronic multisystemic disease associated with a significant morbidity and mortality rate. The treatment of choice is transsphenoidal surgery (TSS) because of its low risk of mortality and few complications.

Aims

To determine the cure prevalence after TSS of growth hormone (GH) secreting pituitary adenomas. To analyze the predictive factors of non-remission after the surgery.

Materials and methods

Retrospective study of 97 patients with acromegaly diagnosis who underwent surgery (n=86) in La Paz University Hospital from 2000 to 2020. The surgery was carried by three neurosurgeons who meet the requirements of being experts in pituitary gland surgery. We performed a descriptive analysis of the patient`s baseline characteristics and surgery outcomes. A multivariate regression analysis was used to review the possible predictive factors of non-healing. Remission was defined if the age and sex-adjusted IGF-1 level were normal and either the basal GH was <1ng/ml or the nadir GH was <0.4ng/ml following oral glucose tolerance test and absence of tumor on MRI.

Results

Out of the total sample, 56.1% were female and 43.9% were male. Diagnostic suspicion was due to symptoms that were secondary to hormonal hypersecretion in 76.3%. GH-secreting pituitary adenoma was found in 94.1% (36.5% microadenomas and 57.6% macroadenomas) of the total patients. 70% of pituitary adenomas showed signs of extension (51% microadenomas and 65% macroadenomas). The surgical cure rate overall was 53.4% (76.9% microadenomas). Tumor remnants were found on MRI in 40% of the patients (23.07% microadenomas and 57.7% macroadenomas). Recurrence occurred in 2.7% of them. Surgical reintervention was performed in 13.3% and radiation therapy was required in 26.5%. Medical treatment was indicated in 94.1% of patients who were not cured and in 6.8% of patients with recurrence. Median GH levels after surgery were 1.6ng/dl (IQR 73.93ng/dl) and IGF-1 257ng/dl (IQR 1095 ng/dl). Multivariate analysis indicated that the non-healing post-surgical predictive factors were IGF-1 values above the upper limit of normal (x LSN) [OR: 9.95 (2.71-53.82)], GH x LSN [OR: 9.62 (3.04-41.65)], macroadenoma [OR: 21.57 (3.08-228.04)], GH + PRL cosecretion [OR 10.84 (1.68-103.4)] and GH + PRL + TSH [OR 33.86 (1.30-1390)].

Conclusions

1) TSS continues to be the first line treatment in acromegaly, although in large and/or invasive adenomas other therapies may be required. 2) Tumor size and initial GH and IGF-1 values are factors that most influence surgical outcomes. 3) TSS performed by an expert surgeon increased higher cure rates.