Mayo Logo Thyroid cancer rates are probably increasing worldwide and novel discoveries may help improve treatment. The following article can probably be added to the list of treatments for thyroid cancer. Scientists from the Mayo Clinic claim that the drug pazopanib aids in revolutionizing care of patients with metastatic, rapidly progressive differentiated thyroid cancers.

The study was undertaken on 37 patients with the most aggressive form of thyroid cancer. This type of cancer apparently develops in less than 5 percent of patients with differentiated thyroid cancer. The authors observed that 18 patients had a long-lasting response to pazopanib. Among the study subjects 12 are still alive without disease progression. It was mentioned that the median progression-free survival time was 11.7 months, with an overall survival rate of 81 percent at one year.

Keith Bible, M.D., Ph.D., a medical oncologist and researcher who led the multicenter clinical trial, alleged, “In this group of patients, we would have expected the cancer to have progressed in everyone within six months, but instead the median time to progression was almost a year in response to pazopanib therapy.”

Though the drug supposedly displayed positive effects, experts caution that pazopanib is not meant to be used in slow-growing differentiated thyroid cancers. It was also noted that scientists were unable to gauge the survival advantage this drug offers to study subjects. A randomized clinical trial can be commenced for ascertaining survival benefits that inhibit all three vascular endothelial growth factor (VEGF) receptors, as compared to other treatments or a placebo.

Dr. Bible, commented, “Further studies of pazopanib in advanced thyroid cancer remain ongoing at Mayo Clinic and associated cancer centers to continue to learn more about how best to use the drug in these cancers. Such clinical trials also may provide patients access to this drug, which otherwise may be unobtainable due to cost, given that it is not yet approved for use in thyroid cancers.”

Significant side effects also appeared on completion of the investigations. Since oncologists judged that side effects have become potentially threatening or debilitating, drug dose was lowered in 16 patients. On the other hand, two patients went through immense bleeding. Two patients died due to pre-existing disease, wherein it has been presumed that the drug must have contributed in some way. Currently authors are planning a larger phase III clinical trial with aggressive differentiated thyroid cancer patients in Europe.

The study will be published in The Lancet Oncology.