DAVID KLEINBERG, MD: Acromegaly is a disease of excess growth hormone. And the effects that excess growth hormone has usually comes from a pituitary tumor and accounts for overly 99% of the acromegalic cases. So the tumor can cause a problem or the excess growth hormone can cause a problem.
ANNOUNCER: The problems related to the tumor itself are called "mass effects." They occur when the tumor grows against structures in the brain.
ANN DANOFF, MD: The mass effect can result in symptomatic headaches and can also result in cranial nerve problems. There are a bunch of nerves that are very important for visual function that run right in the area of the pituitary. The optic chiasm, which supplies the nerve to the eyes, sits right, very close to the top of the pituitary gland. And if the pituitary gland enlarges, it can press on the optic chiasm and cause visual field problems.
ANNOUNCER: The hormonal effects stem from the increase in growth hormone, and include arthritis, trouble sleeping, tumors, heart problems and lung problems.
The hormonal effects also cause the growth and thickening of tissue, leading to the enlargement of internal organs, as well as noses, the brow, feet and hands. The growth of the tumors responsible for acromegaly is very slow, and so is the increase in levels of growth hormone. Often patients do not notice signs of change.
ANN DANOFF, MD: I remember the first patient I ever took care of with acromegaly, who just didn't realize that he had a problem. He was an auto mechanic and his kind of understanding about why his hands were getting bigger was because he was using his hands, working on cars all the time.
ANNOUNCER: When a doctor suspects acromegaly, diagnosis is usually quite simple. Blood tests detect elevated levels of growth hormone, and a related hormone called insulin-like growth factor 1, or IGF-1.
When discovered early, treatment with surgery can have a very good outcome.
ANN DANOFF, MD: For the lucky people who have small tumors there's a very good chance of having a surgical cure. So if you've got a small tumor causing acromegaly, something that's caught early, surgery would be a very reasonable first approach.
ANNOUNCER: When the tumor is large, or spread around blood vessels or the optic nerve, surgery is less likely to cure the disease. Doctors sometimes will try radiation therapy. But usually they move on to treatment with medicines. A drug that mimics a naturally-occurring hormone, somatostatin, is often very effective.
DAVID KLEINBERG, MD: Somatostatin normally controls growth hormone secretion. So it is produced in the body and it has a very important mechanism in the normal control of production of growth hormone.
ANN DANOFF, MD: In the situations where surgery is not a cure, somatostatin analogues play a key role in normalizing both growth hormone and IGF-1 levels.
ANNOUNCER: The somatostatin analogue available in the US is called Sandostatin. It is very effective in relieving the symptoms of acromegaly, and there is some evidence it also affects the growth of the tumor.
DAVID KLEINBERG, MD: Somatostatin analogues or Sandostatin can be effective in reducing tumor size. So either 30 or 50% of tumors will have some shrinkage. The others may not have shrinkage, but it's very rare to see growth of tumor when people are on this medication, so it is possible that there is prevention of further growth once you start treating the tumor when it's a certain size.
ANNOUNCER: Another drug useful in treating a acromegaly in a minority of patients are dopamine agonists. Like somatostatin analogues, they attach to receptors on tumor cells, and reduce the secretion of hormones.
A much different approach is to limit the effects of growth hormone, rather than cut its production by the tumor. This can be done with a drug called Somavert. It's called a growth hormone, or GH, receptor antagonist.
DAVID KLEINBERG, MD: The GH receptor antagonists are actually a kind of growth hormone. And the growth hormone molecule has been changed so that it binds to the growth hormone receptor, but it prevents growth hormone action. And this medication helps symptoms and signs of acromegaly because it blocks the effect of growth hormone, not the growth hormone itself.
ANNOUNCER: However, growth hormone receptor antagonists do not appear to reduce tumor size.
Doctors using it monitor their patients, to make sure there are no ill effects from possible increases in tumor mass.
DAVID KLEINBERG, MD: One has to be very cognizant of the fact that these tumors might grow while you're taking the medication. I think that the jury is not in on the exact incidence of tumor growth after taking this medication for a relatively long period of time. But we do know that it doesn't inhibit tumor growth.
ANNOUNCER: While acromegaly usually progresses slowly, it can have significant impact on peoples lives. But much progress has been made in recent years, especially in medical therapy.
ANN DANOFF, MD: I think in this day and age, with the appropriate diagnosis, and hopefully earlier diagnosis, and appropriate treatments, people, most people, can be very well-controlled and very well-managed. And shouldn't need to suffer from the consequences associated with acromegaly.