Most clinicians favor thyrotropin suppressive therapy with levothyroxine for patients with papillary cancer, although the benefit of such suppression has not been clearly documented in patients with low- risk tumors. Cancer recurrence and the mortality rate may be higher in patients who are inadequately treated with levothyroxine, possibly because of thyrotropin stimulation of thyroid cancer cell growth.[11] If thyrotropin suppressive therapy is used, it is not currently certain to what level the serum thyrotropin must be suppressed to maximize the benefit of therapy, while avoiding long-term potential complications of excessive levothyroxine administration (eg, increased bone loss [particularly in postmenopausal women], cardiac hypertrophy, or cardiac arrhythmias).[12] [13] In patients with low-risk tumors, it may be reasonable to give levothyroxine in doses that maintain thyrotropin at or just below the lower limits of normal. In patients with higher-risk tumors, however, more aggressive therapy to produce thyrotropin levels that are undetectable in third-generation thyrotropin assays is recommended by some experts, although the benefit of such therapy and how long to maintain thyrotropin suppression has not been established.