Prediction models for 5-year, 10-year, and 20-year overall survival (OS) and cause-specific survival (CSS) rates in patients with medullary thyroid carcinoma (MTC) based on lymph node ratio (LNR) have been constructed in a cohort study, with results of the analysis published in the journal Frontiers in Surgery.
The investigators sought to explore the predictive value of LNR for the prognosis of patients with MTC. LNR was defined as “the number of positive lymph nodes divided by the number of lymph nodes resected,” which is widely accepted as a potential prognostic factor in tumors.
The LNR reflects the extent of a tumor, which harbors a high value suggestive of tumor stage and prognosis, and also reflects surgical and pathologic standards. Although prior studies have explored the predictive ability of the number of positive lymph nodes on the prognosis of MTC, the predictive value of LNR for the short-term and long-term outcomes of patients with MTC remains to be elucidated.
The current study obtained data involving 2093 adults with MTC who were undergoing total thyroidectomy and neck lymph node dissection. Kaplan-Meier curves and log-rank tests were utilized to compare the survival curves of 2 groups: those with an LNR of less than 15% and those with an LNR of 15% or greater. All data were divided into 2 sets: the training set (n=1465) and the testing set (n=628).
The random survival forest model was constructed in the training set and subsequently validated in the testing set. Area under the curve (AUC) was utilized for assessment of the predictive ability of the model.
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Results of the study demonstrated that 5-year, 10-year, and 20-year OS and CSS rates of patients with MTC and an LNR under 15% were higher than those with an LNR of 15% or higher. After a 20-year follow-up period, the OS was 46% and the CSS was 75%.
The AUC of the model for 5-year, 10-year, and 20-year OS rates in patients with MTC was 0.878 (95% CI, 0.856-0.900), 0.859 (95% CI, 0.838-0.879), and 0.843 (95% CI, 0.823-0.862), respectively, in the training set. In the testing set, the respective AUCs were 0.845 (95% CI, 0.807-0.883), 0.841 (95% CI, 0.807-0.875), and 0.841 (95% CI, 0.811-0.872).
Additionally, the AUCs for 5-year, 10-year, and 20-year CSS rates in patients with MTC were 0.869 (95% CI, 0.845-0.892), 0.843 (95% CI, 0.821-0.865), and 0.819 (95% CI, 0.798-0.840), respectively, in the training set. In the testing set, the respective AUCs were 0.857 (95% CI, 0.822-0.892), 0.839 (95% CI, 0.805-0.873), and 0.826 (95% CI, 0.794-0.857).
The researchers concluded, “The models displayed good predictive performance.” This might help to “identify [patients with] MTC [who] might have poor outcomes and [in whom] appropriate interventions should be applied.”
An Y, Lu J, Hu M, Cao Q. A prediction model for the 5-year, 10-year and 20-year mortality of medullary thyroid carcinoma patients based on lymph node ratio and other predictors. Front Surg. 2023;9:1044971. doi:10.3389/fsurg.2022.1044971