Drug Shows Promise for Thyroid Cancer

Pazopanib, a drug that halts blood-vessel growth in tumors, has been shown to be effective in a large number of patients with advanced differentiated thyroid cancers.

Of these patients, it's estimated two-thirds of them will have a response lasting longer than a year.

Thyroid cancer patients have doubled over the past 10 years, but most of these patients face a favorable prognosis thanks to surgery and radioiodine treatments. About 5 percent of patients go on to develop a rapidly progressive life-threatening variant of the disease that is resistant to most treatments.

In patients with differentiated thyroid cancers, antiangiogenetic drugs (those that target new blood-vessel growth in tumors) have shown promising clinical activity.

For this study, Keith Bible from the Mayo Clinic, Rochester, and cohorts from around the world analyzed the efficacy and safety of the antiangiogenetic pazopanib and found that of 37 patients with advanced, rapidly progressing thyroid cancer, 18 (49 percent) had their tumors shrink.

This partial response rate suggests very favorable results for the drug in patients with differentiated thyroid cancers, the researchers concluded.