Impacts of the American Joint Committee on Cancer (AJCC) 8th edition tumor, node, metastasis (TNM) staging system on outcomes of differentiated thyroid cancer in Thai patients

Abstract

Background: In 2018, the American Joint Committee on Cancer (AJCC) 8 th edition (AJCC8) was introduced to replace the previous version (AJCC7) due to superiority of AJCC8 over AJCC7 for better prediction of survival from thyroid cancer. Aim: To compare AJCC staging systems with the American Thyroid Association (ATA) risk classification for the prediction of 5-year disease-free survival (DFS), and 5-year disease-specific survival (DSS) in Thai patients. Methods: We retrospectively reviewed all patients with histopathologic diagnosis of DTC who were treated at Theptarin Hospital, Bangkok, Thailand from 1987 to 2019. Results: The study cohort included 262 differentiated thyroid cancer (DTC) patients (papillary thyroid cancer 89.7% with a median time of follow-up 7.8 years). The number (%) of patients within each stage group by AJCC7 and AJCC8 respectively are as follows: Stage I: 173 (66.0%) vs. 232 (88.5%), Stage II: 33 (12.6%) vs. 24 (9.2%), Stage III: 36 (13.7%) vs. 2 (0.8%), Stage IV: 20 (7.7%) vs. 4 (1.5%). The ATA high risk group was found in 24.3% of AJCC7 Stage I compared with 23.7% of AJCC8 Stage I. The 5-year DFS rates in patients classified as stages I, II, III, and IV by AJCC8 were 87.9%, 45.8%, 0% and 25%, respectively. The 5-year DSS rates in patients classified as stages I, II, III and IV by AJCC8 were 98.7%, 100%, 100% and 0%, respectively. AJCC8 was more predictive of DFS rate than AJCC7. Conclusions: Our study is in accord with previous studies that AJCC8 downstage a significant percentage of patients with DTC and correlated with better prognostic validity. However, even a person at low risk for mortality can be at high risk for recurrence.

Comparison of the prognostic value of AJCC cancer staging system 7th and 8th editions for differentiated thyroid cancer

“…Although the TNM classification was created to evaluate mortality in patients with DTC, it is worth noting that in the present study, a significantly higher proportion of patients with structural persistence was observed in SIII TNM8 compared to TNM7, as also demonstrated by Thai research [ 12 ] These findings can be explained by the fact that all tumors with gross local extension were eventually downstaged from SIV.…”

Clinical inertia in thyrotropin suppressive therapy for low-risk differentiated thyroid cancer: A real-world experience at an endocrine center in Bangkok

“…[21] Our previous study also confirmed that a 5-year disease-specific survival was 98.7% in patients with American Joint Committee on Cancer 8th edition stages I. [22] Complications from RAI and TSH suppression therapy have received less attention than surgical complications due to the longer temporal relationship between exposure and development of adverse events. The primary goal of DTC treatments is to ensure the most effective and least invasive treatment and reducing the risk of persistent/recurrent disease.…”

PSG7 indicates that age at diagnosis is associated with papillary thyroid carcinoma: A study based on the cancer genome atlas data

“…Growing lines of studies and the latest American Joint Committee on Cancer staging system for differentiated thyroid carcinoma have indicated that the cut-off value of age at diagnosis used for staging increasing from 45 to 55 can allow low-risk patients to avoid aggressive surgical resections and postoperative therapies, improve disease management strategies, and reduce psychosocial and financial burdens ( Mazurat et al, 2013 ; Amin et al, 2017 ; Pontius et al, 2017 ; Kim et al, 2018 ; Shteinshnaider et al, 2018 ; Thewjitcharoen et al, 2021 ). That is, when the age at diagnosis exceeds 55, the overall prognosis worsens because of the increased cause-specific mortality in patients with PTC, and the mechanisms underlying this phenomenon remain elusive.…”

“…It is widely acknowledged that age at diagnosis is a self-contained element of danger for the outcome of PTC patients ( Kim et al, 2017 ; Kauffmann et al, 2018 ). The cutoff value of age at diagnosis increased from 45 to 55 years, which is one of the most prominent features of the AJCC 8th staging system for judging the prognosis of individuals with differentiated thyroid carcinoma, allowing surgeons to better stratify patients to avoid radical surgical procedures and postoperative treatments ( Amin et al, 2017 ; Thewjitcharoen et al, 2021 ). Furthermore, one study combined clinical data with genetic data (differential gene expression, copy number variation, classical pathway alteration, and somatic mutation) and discovered that this current version for thyroid cancer can predict the recurrence rate and survival more accurately compared with the previous version ( Kim et al, 2018 ).…”