High Growth Rate of Benign Thyroid Nodules Bearing RET/PTC Rearrangements

• Published in: The journal of clinical endocrinology and metabolism Vol. 96; no. 6; pp. E916 - E919
• Main Authors: Sapio, Maria Rosaria, Guerra, Anna, Marotta, Vincenzo, Campanile, Elisabetta, Formisano, Raffaele, Deandrea, Maurilio, Motta, Manuela, Limone, Paolo Piero, Fenzi, Gianfranco, Rossi, Guido, Vitale, Mario
• Format: Journal Article
• Language: English
• Published: United States Oxford University Press 01.06.2011
• Subjects: Adult; Aged; Benign; Blotting, Southern; Cytology; Female; Gene Rearrangement; Growth rate; Humans; Male; Middle Aged; Nodules; Oncogene Proteins, Fusion - genetics; Papillary thyroid carcinoma; Prospective Studies; Proto-Oncogene Proteins c-ret - genetics; Ret protein; Thyroid; Thyroid gland; Thyroid Nodule - diagnostic imaging; Thyroid Nodule - genetics; Thyroid Nodule - pathology; Ultrasonography
• ISSN: 0021-972X; 1945-7197; 1945-7197
• DOI: 10.1210/jc.2010-1599

Context:Benign thyroid nodules display a broad range of behaviors from a stationary size to a progressive growth. The RET/PTC oncogene has been documented in a fraction of benign thyroid nodules, besides papillary thyroid carcinomas, and it might therefore influence their growth.Objective:The aim of the present work was to evaluate whether RET/PTC in benign thyroid nodules associates with a different nodular growth rate.Study Design:In this prospective multicentric study, 125 subjects with benign nodules were included. RET rearrangements were analyzed in cytology samples; clinical and ultrasonographic nodule characteristics were assessed at the start and at the end of the study.Results: RET/PTC was present in 19 nodules. The difference between the mean baseline nodular volume of the RET/PTC− and RET/PTC+ nodules was not significant. After 36 months of follow-up, the RET/PTC+ group (n = 16) reached a volume higher than the RET/PTC− group (n = 90) (5.04 ± 2.67 vs. 3.04 ± 2.26 ml; P = 0.0028). We calculated the monthly change of nodule volumes as a percentage of baseline. After a mean follow-up of 36.6 months, the monthly volume increase of nodules bearing a RET rearrangement was 4.3-fold that of nodules with wild-type RET (1.83 ± 1.2 vs. 0.43 ± 1.0% of baseline volume; P < 0.0001).Conclusions:Benign thyroid nodules bearing RET rearrangements grow more rapidly than those with wild-type RET. Searching for RET rearrangements in benign thyroid nodules might be useful to the clinician in choosing the more appropriate and timely therapeutic option.