There are a number of
options to treat thyroid cancer. Surgery, in which a part or the entire thyroid
is removed, can be done in some cases. Radiation therapy with external or
internal radiation is also used. In some cases, the patient is administered
radioactive iodine. In this procedure, the patient takes radioactive iodine
orally, which gets concentrated in the thyroid gland. The radiation selectively
destroys the cells of the thyroid gland without affecting other parts of the
body. Chemotherapy and thyroid hormone therapy are the other options for
treating thyroid cancer.
Vandetanib is a novel anticancer drug already approved for the
treatment of medullary thyroid cancer that has advanced locally or spread to
It follows the principle of targeted therapy, that is, it attacks cancer cells
without affecting normal cells.
A small study evaluated the
efficacy and safety of vandetanib in the treatment of advanced differentiated
thyroid cancer that did not respond to radiotherapy. The study was conducted in
145 patients equal or over the age of 18 years with thyroid cancer (papillary,
follicular or poorly differentiated) in Europe. The patients received either
300 mg of vandetanib per day (72 patients) or a placebo (73 patients).
At the end of the study, it
was observed that 52 patients in the vandetanib group and 61 patients in the
placebo group showed disease progression. The deaths reported at the end of the
study were 19 in the vandetanib group and 21 in the placebo group. Patients in
the vandetanib group had a significantly longer progression-free survival as
compared to those who did not.
Vandetanib is known to be
associated with a serious cardiac side effect called QTc prolongation. This is
an abnormality in the cardiac rhythm, which can even lead to death. QTc
prolongation was observed in 10 patients receiving vandetanib in the study.
Other complications like diarrhea, asthenia and fatigue were also more common
in patients receiving vandetanib.
Three deaths in the study
were attributed to treatment. Among these, the two deaths in the vandetanib
group were due to bleeding from skin metastases and pneumonia, whereas the
death in the placebo group was due to pneumonia.
Further investigation is
necessary to establish the role of vandetanib in the treatment of
differentiated thyroid carcinoma that has spread locally or to distant sites.
Sophie Leboullex et al; Vandetanib in locally advanced or metastatic
differentiated thyroid cancer: a randomised, double-blind, phase 2 trial; The
Lancet Oncology, Volume 13, Issue 9, Pages 897 - 905, September 2012