M.D. Anderson Studies Drug for Thyroid Cancer Testing

The University of Texas M.D. Anderson Cancer Center is studyinga drug that may save thyroid cancer patients time, inconvenience,and discomfort.

M.D. Anderson is one of 14 institutions worldwide studying syntheticrecombinant thyroid stimulating hormone, or TSH (Thyrogen; Genzyme,Inc, Massachusetts). The drug is given to thyroid cancer patientspreparing to have a radioiodine scan.

In the past, patients scheduled for the radioiodine scan wererequired to stop their thyroid hormone replacement therapy. Thishormone "drain," which allows the radioiodine to givethe most accurate image, takes approximately 5 weeks. This periodleaves many patients with severe symptoms of fatigue, bloating,weight gain, muscle swelling, and depression and continues forabout 2 weeks after the patient has had the scan and resumes medication.

The phase III study of recombinant TSH tests whether future patientswill be able to forego the hormone "drain." Instead,the synthetic hormone could be given in a series of injectionsbefore the scan while the patient continues his or her regularhormone medication without interruption. This possibly could savethe patient the discomfort associated with the suspension of themedication.

Recombinant TSH is a synthetic substitute for the substance normallyproduced by the pituitary gland when thyroid hormone levels decline.High levels of TSH are necessary to make the thyroid an absorbent"sponge" for an effective radioiodine test. However,elevated TSH levels may also stimulate tumor growth. RecombinantTSH may provide the temporary TSH boost to make the radioiodinescan effective while reducing the chances of tumor growth.

Possible Cure With Less Severe Side Effects

The purpose of the new study is to demonstrate whether injectionof recombinant TSH is as effective as stopping hormone medicationwith regard to getting accurate radioiodine test results.

"Potentially, this new drug may save patients a tremendousamount of physical discomfort and emotional distress," saidDr. Steven I. Sherman, the endocrinologist who is spearheadingthe study at M. D. Anderson. "Thyroid cancer is a very curabledisease, and this will hopefully be one more way to get our patientsback on their feet more quickly without missing a beat at homeor work."

Although some patients have reported side effects of nausea, fatigueand headache from the new drug, they are minimal compared to theconventional regimen.

Thyroid cancer is a rare disease with fewer than 200,000 casesin the United States; about 13,000 new cases are diagnosed annually.It is a very treatable with surgery and radioiodine, with 85%to 90% of patients considered cured.

The recombinant TSH study is open to any thyroid cancer patientwho would require a radioiodine scan, regardless of where he orshe was diagnosed or underwent treatment, and will require 8 to10 visits to M.D. Anderson over about a 6-week period. Patientsmust have had thyroidectomies or a series of surgeries that wouldbe equivalent to a thyroidectomy.

Individuals who would like more information about the study shouldcall Dr. Sherman's office at (713) 796-7879.