Restoration of gonadal function in males during long-term primary treatment with octreotide-LAR in acromegaly

Safety and tolerability of a very prolonged primary treatment (median follow-up 30 months, range 18–66) with octreotide (OC)-LAR were retrospectively evaluated in 55 acromegalic patients (12 naive, 19 males, aged 58 years, median, range 28–85). IGF-I normalized in 40 patients (73%): from 833±41 (mean±SE) to 291±21µg/L, P <0.0001, and their levels were progressively further suppressed. GH fell to below 2.5µg/L in 39 patients (71%): from 27.7±4.1µg/L to 2.3±0.2µg/L, P <0.0001. No tachyphylaxis was observed throughout the study period, no patient was lost to follow-up and all of them are still on treatment with OC-LAR. Tumor size reduction (ranging from 25 to 70% of basal volume) was observed at MRI control in 43 patients (77% of the whole series and 92% of naive patients) and no increase in tumor size was recorded in any patient. No patient was withdrawn from the study because of adverse effects. No change in thyroid and adrenal function occurred during the treatment. Among the male patients, 50% had low total testosterone levels at treatment start. After 6–18 months of treatment, without any substitutive treatment, testosterone levels increased from 3.1±0.6 to 4.6±0.6µg/L (p=0.03). The percent change vs. baseline was 72±32%. Worsening was not observed in any patient and testosterone levels reached normal range in 100%. Clinical picture was improved in parallel, as for desire, erections and satisfying intercourses. Semen quality and fertility were not evaluated. There was no relationship between testosterone changes and tumor size or shrinkage or PRL levels or GH/IGF-I changes on treatment. In conclusion, the great effectiveness of a 5-year OC-LAR treatment on hormonal levels (IGF-I normalization in 73%) and tumor size (shrinkage in 77%, up to 92% in naive), coupled to the efficacy on gonadal restoration, strengthens its role as primary treatment for acromegaly, even in young males with poor surgical prognosis due to size or invasiveness of the adenoma.