Endocrine Abstracts

Introduction: Elevated levels of somatotropin (ST) and IGF1 in acromegalic patients are associated with high morbidity and mortality. The normalization of ST and IGF1 allows the reversal of most of their negative effects.

Objective: To evaluate characteristics present at diagnosis, predictive of cure, after surgery, in patients with ST-producing tumors.

Methods: Retrospective study including acromegalic patients diagnosed between 1982 and 2012. Patients that underwent surgery and postoperative evaluation were selected. Data regarding tumor characteristics, ST nadir, IGF1 levels and clinical parameters was collected. Independent samples t-test and partial correlation were used for statistical analysis.

Results: We evaluated 47 patients with ST-producing tumors. Mean age at diagnose was 42.0±12.4 years, delay in diagnosis 6.0±4.4 years, tumor size (considering the largest diameter) 18.7±12.6 mm, ST nadir, prior to surgery, 19.2±24.3 ng/ml, and after surgery 5.1±12.0 ng/ml. Patients with cure criteria after surgery were compared with patients with persistent disease (ST nadir after surgery 0.39±0.36 vs 10.24±16.78 ng/ml, P=0.025). No differences were found between the two groups relating the delay in diagnosis (6.1±5.1 vs 6.1±4.4 years, P=0.985), prolactin levels (44.2±98.1 vs 45.9±52.3 ng/ml, P=0.946), IGF1 (807.3±344.9 vs 744.4±323.4 ng/ml, P=0.576) and tumor size (18.6±14.1 vs 18.7±8.7 mm, P=0.982). Differences were found regarding age at diagnosis (48.2±14.3 vs 40.0±9.3 years, P=0.04) and ST nadir before surgery (10.8±9.4 vs 21.9±19.2, P=0.047), this with moderate correlation with postoperative nadir (r=0.415, P=0.008), after controlling for age. There were no differences in the frequency of symptoms and manifestations of the disease between the two groups.

Discussion: Higher levels of ST nadir at diagnostic OGTT confer greater risk of persistent disease after surgery.