Endocrine Abstracts

Objective: Several studies reported that a long-time therapy with somatostatin analogs (SSTa) in acromegaly could induce persistent remission event after drug withdrawal. The aim of this study was to evaluate GH/IGF-I secretion after SSTa discontinuation in a series of acromegalic patients.

Materials and methods: Data of 21 patients regularly referred to our Centre and previously included in a multicentre study, have been updated at the last available follow up. We then extended the analysis to other 7 acromegalic patients selected for SSTa withdrawal from 2008 and 2018. We retrospectively analysed all biochemical data prior and after SSTa withdrawal, including the last follow up available. Drug suspension was suggested after sustained reduction of IGF1 levels towards the lower limit of normal range concomitant with a progressive reduction of the SSTa therapy. Previous irradiation was considered as an exclusion criteria.

Results: We analysed data of 28 patients, mean age 51±14 years, 9 (32%) males, 9 (32%) de novo and 19 (68%) previously operated. After SSTa withdrawal, 23 (82%) patients had a disease relapse after a mean time of 10.9±11.1 months (median 6 months). After a mean time of 9±4 years (median 10 years) from drug withdrawal, 5 (18%) patients are still on remission. In the long term remission group, 2 (7%) patients had been described in the first multicentre study and are still in remission since 12 and 13 years respectively, the remaining 3 (11%) patients are in remission since 10, 9 and 2 years respectively. Overall, the mean duration of treatment before withdrawal was 5±3 years. In a subgroup of 4 (14%) patients who needed to restart therapy, a second trial of withdrawal was possible, but it failed again. We did not observe any difference between patients with and without relapse, in terms of mean dosage, mean time of treatment, GH and IGF1 levels before drug suspension.

Conclusions: our data challenge the previously held concept that medical therapy is always a lifelong requirement and suggest that a successful withdrawal of SSTa is possible, at least in a subset of acromegalic patients.