Treatment options and outlook
Monday, May 4th, 2009
Treatment for papillary or follicular cancer, the two most common forms of thyroid cancer that usually don't spread beyond the neck area, generally consists of surgically removing the thyroid gland, putting the patient on a short-term low-iodine diet, and then administering a dose of radioactive iodine in capsule form. Once patients swallow and digest the capsule, any thyroid cells not removed during surgery will absorb the radioactive iodine; the radioactive iodine then ablates, or destroys, the cells.
Although radioactive iodine, or I-131, is known to cause thyroid cancer (because the thyroid gland functions to absorb iodine, whether radioactive or not), a form of radioiodine (RAI) works as a cure to kill off any remaining cancerous cells.
Depending on the dose a physician prescribes, the radioiodine treatment does not always include a hospital stay. Patients receiving a dose of less than 30 millicurie can return home; however, they must be sequestered so as not to expose others to the radioiodine.
The so-called “magic bullet,” does not work on all types of thyroid cancer. Patients diagnosed with medullary and anaplastic thyroid cancer often undergo radiation therapy and chemotherapy because the cancers do not respond to radioiodine. That's because medullary cancer develops in C cells, which produce hormones that regulate the amount of calcium in the blood. In contrast, papillary and follicular thyroid cancers, develop in follicular cells, which use iodine from the blood to make thyroid hormones, according to the National Cancer Institute. These cells are destroyed when they absorb the radioiodine.
Anaplastic thyroid cancer, a rare but aggressive cancer that spreads quickly, looks very different from normal thyroid cells under a microscope. Experts say it is the most lethal thyroid cancer.
Long-term survival rate is high
Still, 95 percent of thyroid cancer patients who have their thyroids removed and radioactive iodine treatment have an expected survival rate of 40 years.
In addition, many cancer centers now offer clinical trials for new drugs to help patients with the more aggressive forms of thyroid cancer.
“The gratifying thing is we are seeing patients who have progressive, metastatic thyroid cancer who in the past we had nothing for, are now having the cancer not only stabilize but a substantial minority of patients, not a majority, but certainly a minority of them are seeing tumor shrinkage,” said Dr. Robert Smallridge, the chair of endocrinology at Mayo Clinic Jacksonville.
He says many doctors still don’t know the clinical trials are now available, so patients need to ask about them.
