The Journal of clinical endocrinology and metabolism 2017 12 06() doi 10.1210/jc.2017-02255
Age at diagnosis has been identified as a major determinant of thyroid cancer-specific survival with older patients being at higher risk for mortality, but the association of age with risk of recurrence has not been studied to date.
To examine the effect of patient’s age on response to therapy and disease-specific mortality in a cohort of thyroid cancer patients at high-risk of recurrence as defined by the American Thyroid Association (ATA) risk stratification system.
Retrospective cohort study of 320 patients, median age 49.3 years, with follicular-cell derived thyroid carcinoma classified at ATA High-Risk and followed for a median of 7 years.
Main Outcomes Measured
Association of age with response to therapy, overall mortality, disease-specific mortality and timing of metastases.
Age was a major determinant of response to therapy. There was a significantly larger percentage of excellent responders among young patients (age <55) than among old patients (age ≥ 55), 40.3% vs. 27.5%, p=0.002, respectively, while the proportion of structural incomplete responders was higher in the old group compared to the young group, 53% vs. 33%, p=0.002, respectively. ATA high-risk young patients with a structural incomplete response to therapy had a significantly better disease-specific survival than old patients (74% vs. 12%, p<0.001, respectively). Conclusions
Age was a key predictor of response to therapy and disease-specific survival in ATA High-risk thyroid cancer patients. Its incorporation as a variable in the ATA risk stratification system would improve its power to predict response to therapy as well as mortality.