Defining a Valid Age Cutoff in Staging of Well-Differentiated XXXX .

@entity1 @entity66 @entity5 @entity3 @entity259
BACKGROUND: Age 45  years is used as a cutoff in the staging of well-differentiated @entity259 (WDTC) as it represents the median age of most datasets. The aim of this study was to determine a statistically optimized age threshold using a large dataset of @entity1 treated at a comprehensive @entity5 center. METHODS: Overall, 1807 @entity1 with a median follow-up of 109  months were included in the study. Recursive partitioning was used to determine which American Joint Committee on @entity5 (AJCC) variables were most predictive of disease-specific death, and whether a different cutoff for age would be found. From the resulting tree, a new age cutoff was picked and @entity1 were restaged using this new cutoff. RESULTS: The 10-year @entity66 ( @entity66 ) by Union for International @entity5 Control (AJCC/UICC) stage was 99.6, 100, 96, and 81  % for stages I-IV, respectively. Using recursive partitioning, the presence of distant @entity3 was the most powerful predictor of @entity66 . For M0 @entity1 , age was the next most powerful predictor, with a cutoff of 56  years. For M1 @entity1 , a cutoff at 54  years was most predictive. Having reviewed the analysis, age 55  years was selected as a more robust age cutoff than 45  years. The 10-year @entity66 by new stage (using age 55  years as the cutoff) was 99.2, 98, 100, and 74  % for stages I-IV, respectively. CONCLUSION: A change in age cutoff in the AJCC/UICC staging for WDTC to 55  years would improve the accuracy of the system and appropriately prevent low-risk @entity1 being overstaged and overtreated.
