Establishing Risk Factor Assessment in Papillary Thyroid Microcarcinoma

Thyroid cancer, medically 3D illustration, front view: © Axel Kock - stock.adobe.com

Establishing an assessment that incorporates radiomics may serve as a useful clinical tool for determining the risk of developing central lymph node metastasis in patients with clinically node-negative papillary thyroid microcarcinoma.¹

While outcomes of papillary thyroid microcarcinoma are generally positive, patients with node metastases can experience higher rates of local recurrence and disease metastasis. Moreover, the decision to perform prophylactic lymph node dissection among these patients is controversial and has its own associated risks.

While several studies have attempted to develop predictive models for node-negative papillary microcarcinoma, this marks the first that has used radiomics, converting imaging data into quantitative values for analysis.

“The 6 feature–based Rad score exhibited a significant association with the risk of [central lymph node metastasis]. Moreover, combining this score with other clinical and US factors, the nomogram provided strong predictive power in the training and validation cohorts. These results suggest that this radiomics-based predictive model is a noninvasive, objective, and reliable tool for the preoperative prediction of [central lymph node metastasis],” authors wrote in the study published in Thyroid Research.

According to a multivariate analysis, a higher Rad score (P <.001), younger age (P =.006), and the presence of capsule invasion (P =.030) were independently associated with higher risk of central lymph node metastasis. Following this analysis, researchers created a nomogram accounting for these 3 factors, which yielded promising results.

The area under the curve values of the Rad score for predicting central lymph node metastasis were 0.768 (95% CI, 0.714-0.821) and 0.745 (95% CI, 0.665-0.826) in the training and validation cohorts, respectively.

The study also investigated the role of BRAF mutations papillary thyroid microcarcinoma initiation, progression, and metastasis. Previous studies have identified a link between BRAF mutations and central lymph node metastasis.^2,3 This study also observed the same; however, researchers controlled for BRAF status, so the predictive accuracy of the scoring system was not confounded by this.

As this was a retrospective study with a small sample size of 327 and 153 patients in the training and validation cohorts, respectively, these limitations may impact the validity of the findings. However, these preliminary results warrant investigation in a larger cohort, according to study authors.

REFERENCES:

1. Liu, J., Yu, J., Wei, Y. et al. Ultrasound radiomics signature for predicting central lymph node metastasis in clinically node-negative papillary thyroid microcarcinoma. Thyroid Res. 2024;17(1):4. Published 2024 Feb 19. doi:10.1186/s13044-024-00191-x

2. Zhu D, Wu X, Zhang L, Chen Z. Predictive Value of Ultrasound Imaging Characteristics and a BRAF V600E Nomogram for Central Lymph Node Metastasis Risk in papillary thyroid microcarcinoma. Altern Ther Health Med. 2023;29(8):139-143.

3. Zhao F, Wang P, Yu C, et al. A LASSO-based model to predict central lymph node metastasis in preoperative patients with cN0 papillary thyroid cancer. Front Oncol. 2023;13:1034047. Published 2023 Jan 25. doi:10.3389/fonc.2023.1034047