Impact of the updated TNM staging criteria on prediction of persistent disease in a differentiated thyroid carcinoma cohort

ABSTRACT Objective: The 8th TNM system edition (TNM-8) released in 2018 presents significant changes when compared to the 7th edition (TNM-7). The aim of this study was to assess the impact of changing the TNM staging criteria on the outcomes in a Brazilian cohort of differentiated thyroid carcinoma (DTC). Subjects and methods: DTC patients, attending a tertiary, University-based hospital, were classified by TNM-7 and TNM-8. Prediction of disease outcomes status of the two systems was compared in a retrospective cohort study design. Results: Four hundred and nineteen DTC patients were evaluated, comprised by 82% (345/419) women, with mean age at diagnosis of 46.4 ± 15.6 years, 89% (372/419) papillary thyroid carcinoma, with a median tumor size of 2.3 cm (P25-P75, 1.3-3.5). One hundred and sixty patients (38%) had lymph node metastases and 47 (11%) distant metastases at diagnosis. Using the TNM-7 criteria, 236 (56%) patients were classified as Stage I, 50 (12%) as Stage II, 75 (18%) as Stage III and 58 (14%) as Stage IV. When evaluated by the TNM-8, 339 (81%) patients were classified as Stage I, 64 (15%) as Stage II, 2 (0.5%) as Stage III and 14(3%) as Stage IV. After a median follow-up of 4.4years (P25-P75 2.6-6.6), the rate of incomplete biochemical and/or structural response was 54% vs. 92% (P = 0.004) and incomplete structural response was 42% vs. 86% (P = 0.009) for patients classified as stage IV by TNM-7 vs TNM-8, respectively. Only 4 (1%) disease-related deaths were recorded. Conclusions: In our cohort, 37% of DTC patients were down staged with the application of TNM-8 (vs. TNM-7). Additionally, TNM-8 seems to better stratify the risk of structural incomplete response at follow-up.

Thyroglobulin measurements in washout of fine needle aspirates in cervical lymph nodes for detection of papillary thyroid cancer metastases / Determinação da tireoglobulina no lavado da agulha da punção aspirativa de linfonodos cervicais para detecção de metástases do câncer papilar de tireoide

OBJECTIVE: The aim of this study was to evaluate the accuracy of the measurement of thyroglobulin in washout needle aspiration biopsy (FNAB-Tg) to detect papillary thyroid cancer (PTC) metastases. SUBJECTS AND METHODS: Forty-three patients (51.4 ± 14.6 years) with PTC diagnosis and evidence of enlarged cervical lymph nodes (LN) were included. An ultrasound-guided fine-needle aspiration of suspicious LN was performed, for both cytological examination and measurement of FNAB-Tg. RESULTS: The median values of FNAB-Tg in patients with metastatic LN (n = 5) was 3,419 ng/mL (11.1-25,538), while patients without LN metastasis (n = 38) showed levels of 3.7 ng/mL (0.8-7.4). Considering a 10 ng/mL cutoff value for FNAB-Tg, the sensitivity and specificity was 100 percent. There were no differences on the median of FNAB-Tg measurements between those on (TSH 0.07 mUI/mL) or off levothyroxine (TSH 97.4 mUI/mL) therapy (3.3 vs. 3.8 ng/mL, respectively; P = 0.2). CONCLUSION: The results show that evaluation of FNAB-Tg in cervical LN is a valuable diagnostic tool for PTC metastases that can be used independent of the thyroid status.

OBJETIVO: O objetivo deste estudo foi avaliar a acurácia da dosagem de tireoglobulina no lavado da agulha da punção aspirativa (PAAF-Tg) de linfonodos (LN) cervicais para detecção de metástases do câncer papilar de tireoide (CPT). SUJEITOS E MÉTODOS: Foram incluídos 43 pacientes (51,4 ± 14,6 anos) com diagnóstico de CPT e evidência de LN cervicais aumentados. Os LN suspeitos foram submetidos à punção aspiração com agulha fina guiada por ecografia para análise citológica e dosagem de tireoglobulina (PAAF-Tg). RESULTADOS: A mediana dos valores de PAAF-Tg nos LN metastáticos (n = 5) foi 3.419,0 ng/mL (11,1-25.538), enquanto nos LN não metastáticos (n= 38) a mediana foi de 3,7 ng/mL (0,8-7,4). Utilizando-se o nível de 10 ng/mL como ponto de corte, observaram-se sensibilidade e especificidade de 100 por cento. Os níveis de TSH sérico não interferiram na dosagem de PAAF-Tg (3,3 e 3,8 ng/mL nos grupos com TSH supresso (TSH 0,07 mUI/mL) e hipotireoidismo (TSH 97,4 mUI/mL), respectivamente, P = 0,2). CONCLUSÃO: Os resultados demonstram que a dosagem de PAAF-Tg é uma ferramenta importante no diagnóstico de metástases do CPT, podendo ser utilizada independente do "status" tireoidiano.