Posted: June 6, 2013

At the annual meeting of the American Society of Clinical Oncology researchers have finally revealed what people have been gossiping about for a couple of years: that Tyrosine Kinase inhibitors might work against advanced thyroid cancer, those cancers that no longer respond to treatment with radioiodine.  This class of drugs, TKI’s for short, achieved notoriety with the release of Gleevec over ten years ago for the treatment of Chronic Myelogenous Leukemia.  Since then many additional TKI’s with a variety of structural changes, have been designed to fight the novel enzymes that cancer cells produce.  Sutent, or Sunitinib, has been used with some success in the treatment of liver and kidney cancers.   Dr. Marcia Brose, from the University of Pennsylvania, led a discussion of her results at the meeting.  Patients who received Sutent did much better than those who did not, but the treatment is still not a magic bullet.  Still, the idea of producing molecules that target the products of the genes mutated in cancer cells, received another boost with the presentation of her results.  How this treatment will fit into the overall plan for patients with thyroid cancer not cured with surgery and follow-up radioiodine remains to be seen, but the results are encouraging.

Update 2020: since this post was created in 2014, additional multifunctional tyrosine kinase inhibitors have become available.  The field is in some disarray over this, since it is difficult to do randomized clinical trials in this uncommon disease.  The big new news is the ability to test for tumor-specific mutations such as the BRAF mutation, usually thought of a occurring in melanoma.  If BRAF is mutated consultants recommend a BRAF inhibitor such as vemurafenib.   Some patients treated with a BRAF inhibitor can regain senstivitiy to radioiodine, making subsequent treatments with radioactive iodine possible.  Other mutations such as RET and TRK are also being looked for in the tumors of these patients.  Stay tuned for future developments!