New Guidelines for Acromegaly Include Advice on Pregnancy

November 10, 2014

The US Endocrine Society has issued a clinical practice guideline for the diagnosis and treatment of acromegaly, a rare condition caused by excess growth hormone in the blood. The guidance, which is cosponsored by the European Society of Endocrinology, is published online October 30 in the Journal of Clinical Endocrinology & Metabolism.

Guidelines on acromegaly were issued by the American Association of Clinical Endocrinologists in 2011, but these are the first recommendations from the Endocrine Society on this condition, chair of the task force that developed the new guidance, Dr Laurence Katznelson (Stanford University, California), told Medscape Medical News.

"It's a review of all the available data, combined with the extensive experience of our task-force members to create a thoughtful approach to the diagnosis and management of this disease," he noted.

"What's new is that there are a number of diagnostic cut points and biochemical tests that are utilized in the diagnosis of acromegaly, and we tried to simplify these…to create more of a standard."

There are also novel recommendations on the place for medical therapy, the use of combination medical therapy, "and guidelines on the approach to a woman patient who has acromegaly and is trying to conceive or who is already pregnant," Dr Katznelson added.

"These guidelines certainly could be used by academic endocrinologists in specialty centers, but also we've written guidance that will meet the needs of clinical endocrinologists and neurosurgeons in the approach to a patient who, for example, may have a new pituitary tumor or who has signs and/or symptoms of acromegaly."

And importantly, "they could also…be used by gynecologists and obstetricians, because we are also dealing here with what to do with a patient who is pregnant," and this guidance is much needed, he emphasized.

Acromegaly Predisposes to Diabetes, Heart Disease, and Sleep Apnea

Acromegaly is usually caused by a noncancerous tumor in the pituitary gland, which manufactures too much growth hormone and spurs the body to overproduce insulinlike growth factor-1 (IGF-1).

Due to the overabundance of growth-promoting hormones, a person with acromegaly may have large hands and feet, thick lips, coarse facial features, a jutting forehead and jaw, and widely spaced teeth. The condition is quite rare, with an estimated three cases diagnosed out of a million people each year. Acromegaly most often occurs in middle-aged men and women. In children, excess growth hormone causes gigantism.

For diagnosis, physicians should not rely on random growth hormone measurements; rather, IGF-1 levels should be assessed in people who have facial features or large extremities associated with acromegaly. When a person has a mass on the pituitary gland, IGF-1 should be measured to rule out acromegaly.

In patients with elevated or equivocal serum IGF-1 levels, the task force recommends confirmation of the diagnosis by finding lack of suppression of growth hormone (to <1 µg/L) following documented hyperglycemia during an oral glucose load.

Acromegaly also predisposes people to a number of medical conditions, including diabetes, hypertension, heart disease, osteoarthritis, and sleep apnea. All patients presenting with acromegaly should be assessed for these associated comorbidities, the guidance states.

"Overabundance of growth hormone and IGF-1 can reduce life span and lower quality of life for people with acromegaly, so it is crucial to identify a treatment plan to control hormone levels and the tumor itself," Dr Katznelson said.

Surgery First, but Individualize Therapy

In the new guideline, the Endocrine Society recommends that surgery to remove tumors from the pituitary gland be considered as the primary therapy for most acromegaly patients.

Successful surgery has the advantage of immediately lowering growth-hormone levels. Five-year disease recurrence rates are small, ranging from 2% to 8%. This approach also provides an opportunity to examine the tumor sample to learn more about the individual's condition.

After surgery to remove the pituitary tumor, an imaging study (usually an MRI scan) to visualize any residual tumor tissue should be conducted at least 12 weeks later.

Patients should also be assessed to see whether the pituitary tumor has caused damage and created a deficiency of other pituitary hormones, a condition called hypopituitarism.

Medical therapy is recommended only in a patient with persistent disease following surgery, and treatment guidance is provided.

Radiation therapy in advised if medical therapy is unavailable, unsuccessful, or not tolerated; stereotactic radiotherapy is recommended over conventional radiotherapy where available.

And people who develop gigantism as children should be treated using surgery as the primary therapy and then using medication or radiation treatment based on the individual's condition and response to treatment.

"The condition often requires individualized treatment because signs and symptoms can vary from patient to patient," Dr Katznelson concluded.

Dr Katznelson, MD reports financial or business/organizational interests with Novartis, Roche, and Pfizer. Disclosures for the coauthors are listed in the article.

J Clin Endocrinol Metab. Published online October 30, 2014. Abstract

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