Discontinuation of somatostatin analogs while acromegaly is in long-term remission

Purpose: We aimed to evaluate the disease activity of medically controlled patients with acromegaly after withdrawal of somatostatin receptor ligands (SRL). Methods: Sixteen patients who were on a stable dose of SRL for more than 2 years and had at least 1 year of remission were included in the study. Five patients were on 10 mg, four were on 20 mg and three were on 30 mg of octreotide; whereas for lanreotide, one was on 60 mg, two were on 90 mg, and one was on 120 mg. All patients had received SRL with 28-day intervals. Basal GH, IGF1, glucose-suppressed GH levels were measured with 3-month intervals for a total of 12 months after withdrawal. Sella MRI evaluation was obtained at 6-month intervals. If the nadir GH level after glucose suppression was >1 ng/ml or IGF1 was above the normal limits during the follow-up period, SRL was restarted. Results: Three months after stopping SRL, 10 (63 %) had biochemical disease recurrence. After 12 months of follow-up, in total 13 (81 %) of the patients recurred. The final basal GH levels before withdrawal, basal GH at month-3, and glucose suppressed GH levels were significantly lower in patients with sustained remission (p = 0.003, p < 0.001, and p = 0.001). Basal GH and glucose suppressed GH levels at month-3 were correlated with the basal GH levels at month-0 (r = 0.6, p = 0.008 and r = 0.5, p = 0.03). Conclusion: The final GH levels prior to discontinuation of SRL should be taken into consideration in patients with acromegaly in long-term remission. Moreover, the first visit 3 months after withdrawal is critically important for determining the future status of remission.