The outcome of surgery for acromegaly: the need for a specialist pituitarysurgeon for all types of growth hormone (GH) secreting adenoma

OBJECTIVE Acromegaly is associated with reduced life expectancy, while ther apeutic 'cure' (defined by achievement of GH levels <5 mU/l) is associated with normalization of life expectancy. Surgery remains the treatment of cho ice but in those in whom operative 'cure' is not achieved, radiotherapy and /or medical treatment are valuable treatment modalities. The chance of subs equent 'cure' with radiotherapy or somatostatin analogue therapy is increas ed if the post-operative GH level is reduced below 30 mU/l. Using strict cr iteria for cure and a single dedicated pituitary surgeon, two large Europea n studies reported 'cure' rates of 42% and 56%. In the Manchester region, s urgery for these patients has been performed by a number of neurosurgeons, with no specific designated pituitary surgeon dominating the picture. We wi shed to examine the impact of this surgical strategy on cure rates and the incidence of a post-operative GH level below 30 mU/l. DESIGN We reviewed the GH results between 1974 and 1997 for every acromegal ic who had been referred to the endocrine departments of the two Manchester hospitals responsible for the majority of pituitary disease referrals in M anchester and who had been subsequently referred for pituitary surgery. PATIENTS AND MEASUREMENTS Seventy-three (33 male) patients had had GH statu s assessed before and after surgery by an OGTT or GH profile. The patients were aged between 19 and 70 (mean 43) years at surgery. Seventy-one underwe nt transsphenoidal and 2 transfrontal surgery. Nine surgeons performed oper ations. RESULTS Eighteen(24.7%) had microadenomas and 51 (69.9%) macroadenomas. In 4 patients (5.5%) insufficient data were available to size the adenoma. 17. 8% of patients were cured by surgery, 38.8% with microadenomas and 11.8% wi th macroadenomas. In addition, of 52 patients whose GH levels were >30 mU/l before surgery, only 27 (51.9%) had GH levels below 30 mU/l post-operative ly (81.8% of microadenomas, 43.2% of macroadenomas). CONCLUSION In comparison with other series, the cure rate in this study is significantly lower. The success in reducing GH levels below 30 mU/l postop eratively is difficult to compare with previously published studies, as few groups have analysed their data in this manner. Nonetheless, of our acrome galic patients with a pretreatment GH level in excess of 30 mU/l, nearly 50 % have similar GH status postoperatively, thereby rendering them less amena ble to cure by alternative therapeutic modalities. This highlights the impo rtance of a specialist pituitary surgeon, not only for GH secreting microad enomas but also for GH secreting macroadenomas. If these patients are not ' cured', the cost of continuing therapy becomes a significant burden on heal th-care costs. In addition, if the postoperative GH levels remain above 30 mU/l the chances of achieving adequate control of GH levels are greatly red uced, thereby increasing mortality rates as well as morbidity in these pati ents.