The variable phenotype and low-risk nature of RAS-positive thyroid nodules

Table 1 Baseline characteristics of the study population and the RAS-positive subgroup

	Number of patients	Number of nodules	Female (%)	Age (years)	Nodule size (cm)	Proportion malignant^a	Mutations detected
Total population	318	362	78.7 %	Range: 21.8–87.7 Median: 55.0	Range: 1.0–6.6 Median: 1.9	33 nodules^b (9.1 %)	17 RAS + 9 BRAF + 3 PAX8-PPARγ +^c
RAS-positive nodules	17	17	88.2 %	Range: 27.1–63.5 Median: 46.0	Range: 1.0–5.6 Median: 1.8	8 nodules (47.1 %)^d	8 HRAS+ (3 G12V, 2 Q61K, 2 Q61R, 1 G13R) 7 NRAS+ (6 Q61R, 1 Q61K) 2 KRAS+ (1 G12V)

^aHistologically proven; ^bof the 362 nodules, 63 were referred to surgery because of non-benign cytology, of which 33 proved malignant; ^cof the three PAX8-PPARγ-positive nodules, two underwent surgery and were proven benign. The third nodule underwent Afirma GEC testing, which was also benign; ^dof the 17 RAS-positive nodules, ten were referred to surgery because of indeterminate or malignant cytology, of which eight proved malignant. GEC, gene expression classifier

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