Endocrine Abstracts

Objective: Long acting somatostatin analogs commonly used as adjuvant treatment of acromegalic patients after noncurative surgery. We aimed to compare the efficacy of octreotide LAR (OCT) and lanreotide Autogel (LAN) in acromegalic patients.

Methods: Sixty-eight patients that cure could not be achieved by transsfenoidal endoscopic or microscopic pituitary surgery between 2003 and 2009 were retrospectively analyzed (25 men and 43 women; mean age 41.1±10.9 years (range 18–65)). The patients, who found to be had a noncurative surgery at controls performed in the postoperative 3rd month were assigned randomly to OCT (30 mg, n=36) and LAN (120 mg, n=32) groups. The patients were evaluated with IGF1 (ng/ml), and OGTT–GH suppression test in the 3rd, 6, 12 and 18th months; pituitary MRI was performed before the treatment and in the 3rd and 12th months. IGF1 levels in the normal boundaries according to age and gender and GH level suppressed below 1 ng/ml as a response to OGTT–GH suppression test were considered to be ‘biochemical cure’.

Results: The OCT and LAN groups were age and sex matched (39.3±12.0 vs 42.7±9.6 years; female/male 25/11 vs 18/14). Average IGF1 and GH values and tumor volumes (cm³) of the patients in LAN and OCT groups were similar in the post-operative period before the medical treatment. A statistically significant decrease was obtained for both OCT and LAN groups in GH and IGF1 levels at each follow-up visit performed in 3rd, 6, 12 and 18th months compared to previous value ((OCT: 8.5±9.2, 6.6±7.6, 4.5±6.5, 3.0±4.0 and 2.3±3.4; 782.3±392.3, 674.9±386.8, 471.7±291.8, 403.7±296.6, and 326.6±228.2), (LAN: 7.9±7.0, 5.4±5.5, 3.2±3.9, 1.7±1.7, and 1.4±1.4; 729.0±237.1, 630.4±253.2, 451.7±219.5, 356.8±211.8 and 259.0±112.7), baseline, 3rd, 6, 12 and 18th months respectively). Tumor shrinkage that evaluated in the 12th month of the treatment was statistically significant in both groups but the percentages of tumor shrinkages (28.5 vs 34.9%, P=0.166) and the rate of patients achieved biochemical cure (69.4 and 78.1%, P=0.154) were similar between OCT and LAN groups.

Conclusion: In acromegalic patients who had noncurative surgery, OCT and LAN treatment options have equal efficacy for ensuring biochemical cure and tumor shrinkage.