Acromegaly - Frequently Asked Questions

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Can Acromegaly Shorten My Life?
Patients with uncontrolled Acromegaly have an increased risk of dying earlier than expected. Lowering of the excessive hormone level to normal reduces this risk. Complications associated with acromegaly that can affect your life span include: heart failure, high blood pressure, abnormal cholesterol, diabetes, snoring and other sleep-related breathing problems, and joint disease.
Why Should I Have Treatment After I’ve Had Surgery to Remove the Tumor and I Feel Better?
Unfortunately, by the time most patients are diagnosed with acromegaly (usually a delay of many years after beginning of symptoms), the pituitary tumor is large and may invade areas that the surgeon cannot easily access or the tumor has invaded surrounding structures. The surgical remission rates depend on the size of the tumor and expertise of the surgeon. Surgery is usually effective in removing the bulk of the tumor, relieving headaches, and improving visual problems, but it may not be possible to remove the entire tumor. Additional treatments are often necessary to lower serum GH and IGF-I levels to normal, in order to reduce the risk of the complications of continued excessive growth hormone production.
My Tumor Makes Growth Hormone, What is the IGF-I Test and Why is it Important?
While the tumor makes growth hormone, its action and effect is dependent on production of IGF-I (insulin-like growth factor-one); Blood IGF-I is produced, primarily in the liver, in response to the amount of GH made by the pituitary gland. The blood IGF-I level is a reliable indicator of overall growth hormone production. Since blood growth hormone levels fluctuate every few minutes over 24 hours, a single growth hormone level is only a “snapshot” in time and does not reflect overall growth hormone production. The blood IGF-I level is the most reliable indicator of overall growth hormone production. A normal blood IGF-I level usually indicates remission or, in patients taking medication, control of acromegaly.
What is Somatomedin-C?
Somatomedin-C is an older name for the same hormone, IGF-I.
What is the Role of Medical Treatment for a Growth Hormone Producing Tumor?
Medical treatment is usually given if patients are not cured by surgery. In some cases, medical therapy may be used as the first line of therapy or for few months before surgery. This depends on the size and location of the tumor. Although medications can lower growth hormone and/or IGF-I levels, they do not always shrink the tumor. Because of the long-term complications of excessive growth hormone (joint problems, diabetes, high blood pressure, facial changes, risk of colon polyps, and premature heart disease and premature death), it is important to reduce growth hormone and/or IGF-I to normal. Radiation therapy to the remaining tumor is another option. Since it may take several years before the radiation therapy is effective, medical treatment is used to control excessive growth hormone production while waiting for the effects of radiation. Medications do not cure the problem - they control it. The medication is effective only as long as it is taken as prescribed.
What Medications are Available for Treatment of Acromegaly?

Currently used drugs include:

  • Dopamine agonist: Cabergoline (Dostinex)
  • Somatostatin analogs: Octreotide (Sandostatin), octreotide LAR (Sandostatin LAR), lanreotide autogel (Somatuline depot).
  • Growth hormone receptor antagonist: Pegvisomant (Somavert).
How Do the Medications Differ?

The dopamine agonist drug cabergoline may improve symptoms but is not very effective, resulting in a normal hormone levels in less than 30%. In addition, patients more likely to respond are those in whom IGF-I and GH levels are only slightly elevated.

Octreotide-LAR and lanreotide autogel lower growth hormone, and therefore, IGF-I levels. They are given as an injection every 28 days or sometimes less frequently. They reduce growth hormone and IGF-I levels in approximately 90% of patients. However lowering these hormone levels to normal occurs in approximately 45% to 60% of patients. Some patients have a better response to the combination of octreotide or lanreotide and cabergoline. In patients who still have mild elevations of IGF-I levels during octreotide or lanreotide treatment, the addition of cabergoline may reduce IGF-I levels to normal. Regardless of which regimen in used, these medications do not cure the disease; they control excessive growth hormone production by the tumor. Therefore, the medication(s) is effective only as long as it is taken regularly.

Pegvisomant (Somavert): This medication does not act on the pituitary tumor - it blocks the action of growth hormone at the liver and other sites to reduce production of IGF-I. Approximately 80% of patients treated with Somavert have a reduction in IGF-I to normal. Because the medication doesn’t act on the tumor, the tumor itself is not treated. Although most tumors that secrete growth hormone grow slowly, there is a risk of continued growth of the tumor in Somavert-treated patients. This medication therefore is not typically used without other treatments if the tumor is large or showing signs of growth. Regular MRI scans are necessary to find out if there is growth of the pituitary tumor in patients treated with Somavert. This medication is given as an injection under the skin with a small needle similar to the needle used to give insulin for diabetes and is self-administered once a day. Sometimes pegvisomant is administered less frequently (one or twice a week) or daily in lower doses in association with octreotide, lanreotide or cabergoline when GH and IGF-I are not completely controlled by these medications alone.

What Are the Side Effects of These Medications?

Cabergoline: Occasional nausea, vomiting, dizziness (especially with standing up quickly). At much higher dosages (us used in patients with Parkinson’s disease) it may cause damage to the heart valves.

Octreotide, lanreotide: When beginning treatment: loose stools, light-colored stools, occasional diarrhea and abdominal cramping. This side effect usually lessens or disappears within 1 to 2 weeks. The long-term side effect is the risk of developing gallstones - approximately 25% of people develop gallstones or gall bladder sludge seen on ultrasound testing. The gallstones usually do not cause a problem, and in most patients do not cause symptoms. However, there is always a small risk of developing problems.

Pegvisomant (Somavert): Development of abnormal liver tests occurs in some patients, more frequently if they have diabetes and/or are co-treated with octreotide or lanreotide. The tests return to normal when the medication is stopped. Therefore, it is recommended that liver tests be measured before beginning treatment and every month for the first 6 months of pegvisomant treatment and at regular intervals afterward. Growth of the remaining tumor has occurred in a few patients; this means that regular MRI studies are necessary to detect this. Previous radiation treatment to the tumor appears to make it less likely that there will be tumor growth, but regular MRI scans are necessary to make sure there is no growth.

Can Medical Treatment Be Used Instead of Surgery for Acromegaly?
Occasionally, but not usually. Most patients have a macroadenoma (tumor greater than 1 cm) at the time of diagnosis. In this situation, surgery to remove as much of the tumor as possible is usually the first treatment. This is particularly important if the tumor is close to the eye nerves (optic chiasm). If the patient cannot undergo surgery, or there is no clear benefit of surgery, medical treatment, preferably with is used.

Does Medical Treatment Shrink the Tumor?
Approximately one-third of patients have a reduction in tumor size when treated with octreotide or lanreotide. The amount of tumor shrinkage is usually modest, approximately 30%. Pegvisomant (Somavert): No; this medication does not act directly on the growth hormone producing tumor - it acts to block the action of growth hormone on the liver and reduces IGF-I production and does not cause reduction in tumor size.
Can Patients Receive Financial Assistance in Receiving These Medications?
  • Sandostatin LAR: The Novartis patient assistance telephone number is: 1-877-LAR-HELP.
  • Somatuline depot: The Ipsen patient assistance number is called PACE and the number is 1-866-435-5677.
  • Pegvisomant (Somavert): The Pfizer Bridge program telephone number is 1-800-645-1280.