Epidemiology, treatment trends and outcomes of acromegaly

The changing landscape of acromegaly - an epidemiological perspective

Acromegaly is a rare disease and thus challenging to accurately quantify epidemiologically. In this comprehensive literature review, we compare different approaches to studying acromegaly from an epidemiological perspective and describe the temporal evolution of the disease pertaining to epidemiological variables, clinical presentation and mortality. We present updated epidemiological data from the population-based Danish cohort of patients with acromegaly (AcroDEN), along with meta-analyses of existing estimates from around the world.Based on this, we conclude that the incidence, prevalence and age at acromegaly diagnosis are all steadily increasing, but with considerable variation between studies. An increased number of incidental cases may contribute to the increase in incidence and age at diagnosis, respectively. The clinical features at presentation are trending toward a milder disease phenotype at diagnosis, and advances in therapeutic options have reduced the mortality of patients with acromegaly to a level similar to that of the general population. Moreover, the underlying cause of death has shifted from cardiovascular to malignant neoplastic diseases.

Hypertension and Acromegaly

Hypertension is one of the most frequent complications in acromegaly, with a median frequency of 33.6% (range, 11%-54.7%). Although the pathogenesis has not been fully elucidated, it probably results from concomitant factors leading to expansion of extracellular fluid volume, increase of peripheral vascular resistance, and development of sleep apnea syndrome. Because the effect of normalization of growth hormone and insulinlike growth factor 1 excess on blood pressure levels is unclear, an early diagnosis of hypertension and prompt antihypertensive treatment are eagerly recommended, regardless of the specific treatment of the acromegalic disease and the level of biochemical control attained.

National acromegaly registries

Acromegaly is a rare disease, associated with multiple organs and systems damage. Thanks to implementation of registries, systematic data gathering, knowledge sharing and standardizing medical practices for optimal care greatly improved. Data concerning 19 national acromegaly registries are available, involving more than 16,000 patients. The weighted mean age of diagnosis is 45.2 years and seems stable over time. A macroadenoma is found in 75% of the cases. The proportion of patients operated (>80%) did not change along time. By contrast, use of radiotherapy has decreased while use of medical therapy increased. If judged on IGF-I levels, acromegaly is controlled in 61.3% of the patients. The disease control rate has improved over time. This is likely due to the development of medical treatment strategies. The collection of data about comorbidities in national registries is much less comprehensive than those about epidemiology, disease control or treatment strategies. The most reported comorbidities are arterial hypertension and diabetes. Data concerning mortality trends are controversial. It seems that cancer has become a leading cause of death in acromegaly patients in the last decade, period in which life expectancy improved, while cardiovascular mortality decreased. In conclusion, acromegaly registries offer a global view of the disease with no "a priori" assumptions. This is of outmost importance, because of the large amount of data and the huge number of associated comorbidities. This will help to establish guidelines for management of this rare disease.

Systemic Complications of Acromegaly and the Impact of the Current Treatment Landscape: An Update

Acromegaly is a chronic systemic disease with many complications and is associated with increased mortality when not adequately treated. Substantial advances in acromegaly treatment, as well as in the treatment of many of its complications, mainly diabetes mellitus, heart failure, and arterial hypertension, were achieved in the last decades. These developments allowed change in both prevalence and severity of some acromegaly complications and furthermore resulted in a reduction of mortality. Currently, mortality seems to be similar to the general population in adequately treated patients with acromegaly. In this review, we update the knowledge in complications of acromegaly and detail the effects of different acromegaly treatment options on these complications. Incidence of mortality, its correlation with GH (cumulative exposure vs last value), and IGF-I levels and the shift in the main cause of mortality in patients with acromegaly are also addressed.

Changes in the management and comorbidities of acromegaly over three decades: the French Acromegaly Registry

CONTEXT

Acromegaly is a rare disease associated with chronic multisystem complications. National registries have been created in several countries.

DESIGN

The French Registry contains data on acromegaly epidemiology, management and comorbidities recorded over more than three decades, retrospectively until 1999 and prospectively from 1999 to 2012.

RESULTS

Data could be analyzed for 999 of the 1034 patients included in the registry (46% males). Disease control, defined as IGF-I normalization (adjusted for age and sex), was achieved in 75% of patients at the last follow-up visit. Half the patients with uncontrolled disease had IGF-I levels below 1.5 times the upper limit of normal (ULN). The proportion of patients with surgically cured disease did not change markedly over time, whereas the proportion of patients with uncontrolled disease fell and the proportion of patients with medically controlled disease rose. Cardiovascular, metabolic, respiratory and rheumatologic comorbidities and their outcomes were recorded for most patients, and no noteworthy overall deterioration was noted over time. Cancer occurred in 10% of patients, for a standardized incidence ratio of 1.34 (95% CI: 0.94-1.87) in men and 1.24 (0.77-1.73) in women. Forty-one patients died during follow-up, for a standardized mortality ratio of 1.05 (0.70-1.42). Most deaths were due to cancer.

CONCLUSIONS

The majority of patients with acromegaly now have successful disease control thanks to the multistep management. The incidence of comorbidities following diagnosis of acromegaly is very low. Life expectancy is now close to that of the general population, probably owing to better management of the GH/IGF-I excess and comorbidities.

The risks of overlooking the diagnosis of secreting pituitary adenomas

Secreting pituitary adenomas that cause acromegaly and Cushing’s disease, as well as prolactinomas and thyrotroph adenomas, are uncommon, usually benign, slow-growing tumours. The rarity of these conditions means that their diagnosis is not familiar to most non-specialist physicians. Consequently, pituitary adenomas may be overlooked and remain untreated, and affected individuals may develop serious comorbidities that reduce their quality of life and life expectancy. Because many signs and symptoms of pituitary adenomas overlap with those of other, more common disorders, general practitioners and non-endocrinology specialists need to be aware of the “red flags” suggestive of these conditions. A long duration of active disease in patients with secreting pituitary adenomas is associated with an increased risk of comorbidities and reduced quality of life. Appropriate treatment can lead to disease remission, and, although some symptoms may persist in some patients, treatment usually reduces the incidence and severity of comorbidities and improves quality of life. Therefore, correct, early diagnosis and characterization of a pituitary adenoma is crucial for patients, to trigger timely, appropriate treatment and to optimize outcome. This article provides an overview of the epidemiology of hormonal syndromes associated with pituitary adenomas, discusses the difficulties of and considerations for their diagnosis, and reviews the comorbidities that may develop, but can be prevented, by accurate diagnosis and appropriate treatment. We hope this review will help general practitioners and non-endocrinology specialists to suspect secreting pituitary adenomas and refer patients to an endocrinologist for confirmation of the diagnosis and treatment.

The place of medical treatment of acromegaly: current status and perspectives

INTRODUCTION

Acromegaly is characterized by elevated growth hormone (GH) and insulin-like growth factor-I (IGF-I) levels and by progressive somatic disfigurement and systemic manifestations, which lead to a mortality rate higher than the general population. Therefore, diagnosis and properly treatment should be performed as soon as possible.

AREAS COVERED

This article focuses on the state of the art of acromegaly medical treatment. Somatostatin analogs, dopamine agonists and GH receptor antagonist were reviewed. Somatostatin analogs, the first-choice pharmacotherapy, can be used as primary or pre-operative treatment or as secondary therapy after failed surgery. Dopamine agonists have been used in patients with slightly elevated hormone levels and/or mixed GH/prolactin adenomas. Pegvisomant is indicated for resistant to somatostatin analogs/dopamine agonists. Combined treatment is also an option for resistant cases. Other non-conventional therapies and perspectives of treatment were also been discussed.

EXPERT OPINION

The control of disease activity in acromegaly is of paramount importance. Medical treatment is an important option for cases in which surgery was unsuccessful or not indicated. Despite the achievements in medical treatment, somatotropic tumor aggressiveness and/or resistance to the drugs currently available remain a concern. Therefore, novel therapy targets based on molecular pathogenesis of GH-secreting tumors are currently in development, aiming at fulfilling this important gap.