Background: In most staging systems, 45 years of age is used to differentiate low risk thyroid cancer from high risk thyroid cancer. However, recent studies have questioned both the precise 45 year age point and the concept of using a binary cut off as accurate predictors of disease specific mortality. Methods: A cohort of 3664 thyroid cancer patients that received surgery and adjuvant treatment at Memorial Sloan Kettering Cancer Center (MSKCC) from the years 1985 to 2010 were analyzed to determine the significance of age at diagnosis as a categorical variable at a variety of age cutoffs (5 year intervals between 30 and 70 years of age). The unadjusted and adjusted hazard ratio for the association between disease-specific survival and age was determined using a Cox proportional hazards model adjusted for other predictive variables sex, histology, and pathological T, N, and M status. Furthermore, predictive nomograms of disease-specific mortality were created and validated on an external dataset of 4551 patients to evaluate the impact of age at diagnosis as both a categorical and continuous variable. Results: In the MSKCC cohort, with a median follow-up time of 54 months (range 1–332), there were 59 deaths from thyroid cancer with a 10 year disease-specific survival of 96%. Adjusted hazard ratios for all age cutoffs from age 30 to age 70 years were significant. There was no specific cutoff age which risk stratifies patients with differentiated thyroid cancer (DTC). Categorizing age into five strata (<40, 40–49, 50–59, 60–69 and >70 years) showed a 37-fold increase in hazard ratio from age <40 years to age >70 years. A predictive nomogram using age as a continuous variable with other predictive variables had a high concordance index of 96%. Validation on the external cohort had a concordance index of 73%. Conclusions: Mortality from DTC increases progressively with advancing age. There is no specific cutoff age which risk stratifies patients with DTC. A predictive nomogram using age as a continuous variable may be a more appropriate tool for stratifying patients with DTC and for predicting outcome.
<p>Supplementary Video S1 shows a Keratin Pearl. Keratin pearls are often present in oral squamous cell carcinoma (OSCC). They are composed of concentric rings of squamous cells showing gradual keratinization.</p>
<p>Supplementary Figure S11 shows in vivo RCM images of a tumor in a 26-year-old male, with no history of tobacco or alcohol exposure. The patient harbored a 2.0 cm poorly differentiated oral squamous cell carcinoma on the right lateral tongue.</p>
<p>Supplementary Figure S5 shows in vivo RCM images of a tumor area in an 84-year-old female patient, with a history of 2 packs of cigarettes per day for 65 years and no history of alcohol exposure, harboring a 3.2-cm infiltrating moderately differentiated oral squamous cell carcinoma of the right lateral tongue.</p>
