EP55 – The McGill Thyroid Nodule Score – Improved Accuracy through Multivariate Logistic Regression

      Sasson, Mark1; Hua, Gordon1; Forest, Veronique-Isabelle2; Payne, Richard2 1 Faculty of Medicine, McGill University, Montreal, QC, Canada 2 Department of Otolaryngology – Head and Neck Surgery, McGill University, Montreal, QC, Canada   Background: The incidence of thyroid nodules in North America is increasing.1,2 While a minority of these nodules are malignant, diagnosis remains challenging.3,4,5 The McGill Thyroid Nodule Score (MTNS+) was developed to calculate the preoperative risk of thyroid malignancy.6 This study proposes an improved MTNS (iMTNS). Methods: A retrospective chart review of 394 patients who underwent thyroidectomies was performed. The MTNS+ variables, thyroid hormones, and American Thyroid Association ultrasound (ATA-US) classification for each patient were compared to their postoperative pathology. Odds ratios were calculated through multivariate logistic regression and new scoring values were consequently assigned to each variable. The iMTNS was compared to the MTNS+ through sensitivity, specificity and area under the receiver operating characteristic (AUC-ROC). Results: A total of 267 cases and 127 controls were gathered. The overall sensitivity and specificity of the iMTNS were 75.3% and 69.3% respectively, while the AUC-ROC was 0.776 (0.731, 0.816, p<0.0001). In comparison, MTNS+ scored a sensitivity and specificity of 61.0% and 70.1% respectively using the gathered data set, and the AUC-ROC was 0.678 (0.629, 0.724, p<0.0001). A score of 5 is the point of maximum convergence for the iMTNS, with the risk of cancer <=5 being 42.8% and the risk >=5 being 80.5%. Discussion & Conclusion: This study incorporates a T4/T3 ratio, and the ATA-US into the iMTNS, allowing for a more accurate malignancy risk prediction in patients with a thyroid nodule. Moreover, it suggests that the iMTNS can improve clinical decision making for these patients.   References:
    1. Bongiovanni M, Spitale A, Faquin WC, Mazzucchelli L, Baloch ZW. The Bethesda System for Reporting Thyroid Cytopathology: a meta-analysis. Acta cytologica. 2012;56(4):333-9.
    2. Dean DS 2008 Epidemeology of thyroid nodules. Best Pract Res Clin Endocrinol Metab. 22(6):901-911.
    3. Yassa L, Cibas ES, Benson CB, Frates MC, Doubilet PM, Gawande AA, et al. Long-term assessment of a multidisciplinary approach to thyroid nodule diagnostic evaluation. Cancer. 2007;111(6):508-16.
    4. Werk EE, Vernon BM, Gonzalez JJ, Ungaro PC, McCoy RC 1984 Cancer in thyroid nodules: a community hospital survey. Arch Intern Med. 144(3):474.
    5. Frates MC, Benson CB, Doubilet PM, Kunreuther E, Contreras M, Cibas ES, Orcutt J, Moore  FD, Larsen PR, Marqusee E, Alexander EK 2006 Prevalence and distribution of carcinoma in patients with solitary and multiple thyroid nodules on sonography. J Clin Endocrinol Metab. 91(9):3411-3417.
    6. Varshney R, Forest VI, Mascarella MA, Zawawi F, Rochon L, Hier MP, et al. The Mcgill thyroid nodule score – does it help with indeterminate thyroid nodules? Journal of otolaryngology – head & neck surgery = Le Journal d’oto-rhino-laryngologie et de chirurgie cervico-faciale. 2015;44:2.


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