Disparities in the impact of the AJCC 8th edition staging system on differentiated thyroid cancer outcomes

• Published in: Head & neck Vol. 44; no. 10; pp. 2129 - 2141
• Main Authors: Santamaria‐Barria, Juan A., Graff‐Baker, Amanda N., Chang, Shu‐Ching, Khader, Adam, Scholer, Anthony J., Garland‐Kledzik, Mary, Goldfarb, Melanie
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01-10-2022; Wiley Subscription Services, Inc
• Subjects: cancer staging; differentiated thyroid cancer; disparities; Ethnicity; Hispanic people; Minority & ethnic groups; Race; Survival; Thyroid cancer
• ISSN: 1043-3074; 1097-0347
• DOI: 10.1002/hed.27122

Background
The impact of AJCC8 among self‐reported racial/ethnic groups on differentiated thyroid cancer (DTC) outcomes is unknown.
Methods
Multivariate‐regression evaluated the association between AJCC7 to AJCC8 stage change and race/ethnicity in patients with DTC in the NCDB. Cox‐proportional‐regression evaluated whether AJCC7 to AJCC8 stage change affects overall survival (OS) differently based on reported race/ethnicity.
Results
After adjusting for confounders, Hispanics and Asian‐Pacific‐Islanders (APIs) were 27% and 12% less likely to be down‐staged compared to white‐non‐Hispanics (WNHs) (p < 0.001); black‐non‐Hispanics (BNHs) had no significant down‐staging difference. Down‐staged patients had an increased risk of death compared to patients with unchanged staging, regardless of race/ethnicity. However, based on two‐way interaction, the magnitude of this negative change on survival from down‐staging was only different between WNHs (HR = 2.64) and BNHs (HR = 1.77), (p = 0.04).
Conclusions
Outcome disparities persist among self‐reported racial/ethnic groups with AJCC8. Down‐staged patients across all racial/ethnic groups had decreased survival compared to those with unchanged stage, with the least impact in BNHs.