[Acromegaly].

Acromegaly is an infrequent disease attributable to endogenous excess of GH and IGF-I. Human studies have associated the GH-IGF-I axis with the development of colorectal cancer; however, the question of whether colorectal cancer is a problem in acromegaly is currently unresolved. We performed a cross-sectional study to assess the risk of colonic neoplasia in patients with acromegaly. Colonoscopic screening was performed in 235 patients with acromegaly at five tertiary care hospitals in Italy between January 1, 1996, and December 31, 2001. A repeat colonoscopy was performed in 121 patients after a mean interval of 32.1 months. Colonoscopic findings in patients with acromegaly were compared with those of 233 patients with nonspecific abdominal complaints who were referred for endoscopy during the study period. A total of 65 patients (27.7%) and 36 controls (15.5%) had colonic neoplasia. In 55 patients (23.4%) and 34 control subjects (14.6%), the most important findings were adenomas (odds ratio, 1.7; range, 1.1-2.5), whereas 10 patients (4.3%) and two control subjects (0.9%) had carcinoma (odds ratio, 4.9; range, 1.1-22.4). The risk of colonic neoplasia was higher for younger patients with acromegaly compared with age-matched controls. Patients with acromegaly with or without colonic neoplasia did not differ significantly for IGF-I levels or duration of disease. A neoplastic recurrence was found in 16.5% of patients who underwent follow-up; 90% of them had had a neoplasm removed at the first colonoscopy. Acromegaly carries with it a moderate, but definitive, increase in the risk of colonic neoplasia that occurs at a younger age than in the general population. Patients who are found to harbor a colonic neoplasia are at risk for recurrence.

Acromegaly↗

PubMed2004

Predicting therapeutic response and degree of pituitary tumour shrinkage during treatment of acromegaly with octreotide LAR.

BACKGROUND/AIMS: The efficacy of transsphenoidal surgery in the treatment of patients with acromegaly is largely dependent on tumour size. A reduction in pituitary tumour volume by medical therapy might therefore improve subsequent surgical cure rates. This study prospectively determined the effects of the depot somatostatin analogue octreotide LAR on pituitary tumour size, GH and IGF-I levels and clinical symptoms in a cohort of previously untreated patients with acromegaly. METHODS: Six patients newly diagnosed with acromegaly (mean age 53 years; range 42-76 years) received intramuscular octreotide LAR every 28 days for 6 months. The initial dose of LAR was 20 mg, but increased to 30 mg after the initial 3 injections if mean GH levels were >5 mU/l. Prior to commencing LAR therapy, each patient received 3 injections of subcutaneous octreotide (50, 100 and 200 mug) in a randomized order on separate days, and the serum GH response was measured. Pituitary tumour volume was calculated from MRI or computed tomography scans at baseline, then 3 and 6 months after initiation of treatment, and assessed by a 'blinded' radiologist in random order. At baseline, 4 patients had a macroadenoma and 2 patients had a microadenoma. For the latter, the whole gland volume was measured. RESULTS: Serum GH levels decreased from 29.6 +/- 19.2 mU/l (mean +/- SD) at baseline to 12.1 +/- 10.5 mU/l at 3 months and 10.4 +/- 9.3 mU/l at 6 months. Three patients achieved a mean serum GH level of <5 mU/l. In these patients, the serum GH had declined to <5 mU/l in response to a single 100 mug subcutaneous octreotide injection. Serum IGF-I levels decreased by a mean of 45 +/- 7.4%. Tumour volume decreased in all patients: mean baseline volume 2,175 mm(3) (range 660-6,998) decreasing to 1,567 mm(3) (range 360-4,522) at 3 months (p < 0.05) and 1,293 mm(3) (range 280-4,104) at 6 months (p < 0.002). The mean percentage decrease in size was 29% (range -54 to +4%) at 3 months (p < 0.02) and 47% (range 21-97%) at 6 months (p < 0.002). There was no statistically significant correlation between GH response and tumour shrinkage. CONCLUSIONS: A single test dose of subcutaneous octreotide may be useful in predicting the subsequent efficacy of octreotide LAR. Octreotide LAR results in significant shrinkage of pituitary tumours of newly diagnosed patients with acromegaly. Whether its administration to such patients for 6-12 months can improve the efficacy of subsequent transsphenoidal surgery will require further study.

Acromegaly↗