LONG-STANDING ACROMEGALY WITH PERSISTENT DISEASE RESPONSIVE TO PASIREOTIDE

A CASE REPORT

Abstract

INTRODUCTION/BACKGROUND
In acromegaly patients, chronic hypersecretion of growth hormone from pituitary adenoma results in significant morbidity and mortality. Achieving biochemical control can be challenging, requiring a combination of pituitary surgery, radiotherapy and medical therapy. Pasireotide, a new multireceptor-targeted somatostatin receptor ligand, has a broader binding profile and an increased affinity for SSTR1, 2, 3, and 5 that has demonstrated superiority compared to Octreotide LAR.

CASE
We report a case of long-standing acromegaly with persistent disease despite pituitary surgery, radiotherapy and Octreotide LAR treatment being switched to pasireotide treatment. A 63-year-old female was diagnosed with acromegaly 12 years ago with an initial pituitary tumour size of 2.6 x 2.7 x 3.8 cm. She underwent initial transsphenoidal resection of the pituitary tumour but post-operatively she still had a residual tumour of 1.0 x 0.9 x 1.4cm. She received initial medical therapy (Octreotide LAR). However, due to persistent disease and residual tumour, she was then subjected to 11 cycles of radiotherapy. Despite radiotherapy, her serum IGF-1 levels remained elevated and she also developed uncontrolled diabetes. At this juncture, she also refused further pituitary surgery and refused an MRI scan due to claustrophobia. Over the next few years, she would be maintained on Octreotide LAR 40 mg. Her IGF-1 levels would fluctuate slightly but never achieved control. Pasireotide treatment was subsequently started for the patient 1 year ago. After initiation of pasireotide, she had shown significant improvement of serum IGF-1 levels from 628.5 ng/ml to 203.4 ng/ml after 4 months of treatment. She also finally agreed to a repeat MRI pituitary which showed minimal residual tumour.

CONCLUSION
This case demonstrated the difficulty in achieving remission in an acromegaly patient despite surgery and radiotherapy. Despite long standing acromegaly disease and long duration of Octreotide LAR treatment, initiation of pasireotide has benefit to bring patient into biochemical and symptom control.