Predicting recurrence of papillary thyroid cancer using the eighth edition of the AJCC/UICC staging system

Abstract

Background: The AJCC/UICC classification is widely used for predicting survival in papillary thyroid cancer (PTC), but has not been evaluated as a predictor of recurrence. The hypothesis of this study was that the eighth edition of the AJCC system can be used in this novel way. Methods: All patients in the study underwent surgery for PTC at a high-volume endocrine surgery centre in France between 1985 and 2015. The seventh and eighth editions of the AJCC/UICC staging system for PTC were employed to predict recurrence and disease-specific survival using the Kaplan–Meier and log rank tests. Results: Among 4124 patients (79.7 per cent female), median age was 50 (i.q.r. 38–60) years; 3906 patients (94.7 per cent) underwent total thyroidectomy, with lymph node dissection in 2495 (60.5 per cent). The eighth edition placed 91.8, 7.1, 0.4 and 0.7 per cent of patients in stages I–IV respectively. After reclassifying patients from the seventh to the eighth AJCC/UICC edition, the disease was downstaged in 23.8 per cent. Over a median follow-up of 7 years, 260 patients (6.4 per cent) developed recurrent disease, including 5.2 per cent of patients with stage I, 19.6 per cent with stage II, 59 per cent with stage III and 50 per cent with stage IV disease, according to the eighth edition. The eighth edition was a better predictor of recurrence than the seventh edition. Conclusion: The eighth edition of the AJCC/UICC staging system appears to be a novel tool for predicting PTC recurrence, which is a meaningful outcome for this indolent disease. The eighth edition can be used to risk-stratify patients, keeping in mind that other molecular and pathological predictive factors must be integrated into the assessment of recurrence risk.

Survival in differentiated thyroid carcinoma: Comparison between the 7th and 8th editions of the AJCC/UICC TNM staging system and the ATA initial risk stratification system

“…Conversely, the ATA IRSS was designed to stratify the DTC patients according to the risk of tumor progression, instead of the death of the disease 3,8 . As the relationship between the events is unquestionable, 3,11,12 TNM has also been frequently used in clinical practice to assess the risk of cancer recurrence and to guide treatment and follow‐up 11 …”

“…Relapses, in turn, affect survival with mortality rates reaching more than 10% if locoregional disease and if an incomplete response to additional treatment is found, 9 escalating to 55% with the development of distant metastases 3,10 . Therefore, disease‐free survival (DFS) has been considered a better predictor of outcome than overall survival (OS), as the death of the disease can actually happen decades after the tumor diagnosis 11,12 . In clinical practice, nonetheless, the applicability of TNM system for recurrence prediction has been suggested 13,14 …”

5‑Hydroxymethylcytosine as a potential epigenetic biomarker in papillary thyroid carcinoma

“…This study also endeavors to evaluate the patients' survival data by directly associating the low 5-hmC levels with PTC prognosis. However, recurrence of PTC following optimized surgery is uncommon, and the latent durations prior to detection of distant and lethal metastases may vary from years to decades (35). The follow-up duration of the current study is not long enough to observe the prognostic value of 5-hmC in PTC.…”

European Thyroid Association and Cardiovascular and Interventional Radiological Society of Europe 2021 Clinical Practice Guideline for the Use of Minimally Invasive Treatments in Malignant Thyroid Lesions

“…Moreover, after complete surgical resection, a followup by US may detect local recurrence in up to 7% of DTC as a whole and in up to 2.4% of PTMC patients [9,10]. Repeat compartment-oriented surgery is the established therapeutic approach for DTC metastases which progressively grow during follow-up, but lymphadenectomy results in biochemical remission only in 21-61% of these patients [11,12].…”