*Article* **CONUT Score: A New Tool for Predicting Prognosis in Patients with Advanced Thyroid Cancer Treated with TKI**

**Cristina Dalmiglio 1, Lucia Brilli 1, Michele Campanile 1, Cristina Ciuoli 1, Alessandra Cartocci <sup>2</sup> and Maria Grazia Castagna 1,\***


**Simple Summary:** Many studies have shown that an impaired nutritional status correlated with a worse prognosis in cancer patients. The aim of our retrospective study was to evaluate the potential role of baseline Controlling Nutritional Status (CONUT score) in predicting prognosis of advanced thyroid cancer treated with tyrosine kinase inhibitors (TKI). We were able to confirm that baseline CONUT score significantly correlated with progression free survival (PFS) and overall survival (OS) and was the only independent prognostic factor for both outcomes. In particular, a CONUT score ≥3 was associated with a worse PFS and OS. The CONUT score represents a relatively new screening tool that is useful in predicting prognosis in thyroid cancer patients before the beginning of anti-tumoral treatment.

**Abstract:** (1) Background: The Controlling Nutritional Status (CONUT) score is an immuno-nutritional screening tool based on serum albumin, total cholesterol, and lymphocyte count. The aim of the study was to assess the CONUT score as a potential prognostic factor of response to therapy in patients with advanced thyroid cancer treated with tyrosine kinase inhibitors (TKIs). (2) Methods: We retrospectively evaluated 42 metastatic thyroid cancer patients (54.8% female). The median age at the time of TKI treatment was 69 years. Histological diagnosis was differentiated thyroid cancer in 66.7%, poorly differentiated thyroid cancer in 21.4%, and medullary thyroid cancer in 11.9% of patients. CONUT score was assessed before starting TKI therapy. (3) Results: Progression-free survival (PFS) and overall survival (OS) were significantly influenced by baseline CONUT score. The best CONUT cut-off able to predict the response to treatment was 3. Both PFS and OS were better in patients with CONUT score <3 than in those with CONUT score ≥3 (*p* < 0.0001). CONUT score was the only independent prognostic factor associated with PFS (*p* = 0.021) and OS (*p* = 0.007). (4) Conclusions: CONUT score represents a relatively new screening tool, easily applicable in clinical practice and potentially useful in predicting prognosis in thyroid cancer patients treated with TKIs.

**Keywords:** CONUT score; thyroid cancer; tyrosine kinase inhibitors
