BACKGROUND: The prevalence of RET somatic mutations in sporadic medullary thyroid cancer (MTCs) is ∼40%-50%, and the most frequent somatic mutation is M918T. RET-positive MTCs have been demonstrated to have a more advanced stage at diagnosis and a worse outcome. AIMS: The aim of the present work was to compare the prevalence of RET somatic mutations in sporadic microMTCs (<1 cm) and in larger MTCs. PATIENTS: We analyzed the M918T RET point mutation in 160 sporadic MTC cases. Tumors were classified according to their size: group A, <1 cm; group B, >1 and <2 cm; group C, >2 and <3 cm; and group D, >3 cm. RESULTS: The overall prevalence of the somatic M918T RET mutation was 19.4% (31/160). RET mutations were distributed differently among the four groups. The prevalence was 11.3% (6/53) in group A, 11.8% (8/68) in group B, 31.8% (7/22) in group C, and 58.8% (10/17) in group D, exhibiting an increase with increasing size of the tumor. When comparing the prevalence of mutations in the four groups, we found a lower prevalence in microMTCs (p<0.0001). CONCLUSIONS: The overall prevalence of RET somatic mutations was lower than expected, and the prevalence of the somatic M918T RET mutation was significantly lower in microMTCs than in larger tumors. To explain this finding, we can hypothesize either that other oncogene(s) might be responsible for the majority of microMTC, thus identifying a tumor subset, or that the RET mutation might, or might not, occur later during tumor progression.
BACKGROUND: The prevalence of RET somatic mutations in sporadic medullary thyroid cancer (MTCs) is ∼40%-50%, and the most frequent somatic mutation is M918T. RET-positive MTCs have been demonstrated to have a more advanced stage at diagnosis and a worse outcome. AIMS: The aim of the present work was to compare the prevalence of RET somatic mutations in sporadic microMTCs (<1 cm) and in larger MTCs. PATIENTS: We analyzed the M918TRET point mutation in 160 sporadic MTC cases. Tumors were classified according to their size: group A, <1 cm; group B, >1 and <2 cm; group C, >2 and <3 cm; and group D, >3 cm. RESULTS: The overall prevalence of the somatic M918TRET mutation was 19.4% (31/160). RET mutations were distributed differently among the four groups. The prevalence was 11.3% (6/53) in group A, 11.8% (8/68) in group B, 31.8% (7/22) in group C, and 58.8% (10/17) in group D, exhibiting an increase with increasing size of the tumor. When comparing the prevalence of mutations in the four groups, we found a lower prevalence in microMTCs (p<0.0001). CONCLUSIONS: The overall prevalence of RET somatic mutations was lower than expected, and the prevalence of the somatic M918TRET mutation was significantly lower in microMTCs than in larger tumors. To explain this finding, we can hypothesize either that other oncogene(s) might be responsible for the majority of microMTC, thus identifying a tumor subset, or that the RET mutation might, or might not, occur later during tumor progression.
Authors: Samuel A Wells; Sylvia L Asa; Henning Dralle; Rossella Elisei; Douglas B Evans; Robert F Gagel; Nancy Lee; Andreas Machens; Jeffrey F Moley; Furio Pacini; Friedhelm Raue; Karin Frank-Raue; Bruce Robinson; M Sara Rosenthal; Massimo Santoro; Martin Schlumberger; Manisha Shah; Steven G Waguespack Journal: Thyroid Date: 2015-06 Impact factor: 6.568
Authors: R Ciampi; C Romei; L Pieruzzi; A Tacito; E Molinaro; L Agate; V Bottici; F Casella; C Ugolini; G Materazzi; F Basolo; R Elisei Journal: J Endocrinol Invest Date: 2016-08-17 Impact factor: 4.256
Authors: Henning Dralle; Thomas J Musholt; Jochen Schabram; Thomas Steinmüller; Andreja Frilling; Dietmar Simon; Peter E Goretzki; Bruno Niederle; Christian Scheuba; Thomas Clerici; Michael Hermann; Jochen Kußmann; Kerstin Lorenz; Christoph Nies; Peter Schabram; Arnold Trupka; Andreas Zielke; Wolfram Karges; Markus Luster; Kurt W Schmid; Dirk Vordermark; Hans-Joachim Schmoll; Reinhard Mühlenberg; Otmar Schober; Harald Rimmele; Andreas Machens Journal: Langenbecks Arch Surg Date: 2013-03-03 Impact factor: 3.445
Authors: Jamie R Oliver; Kepal N Patel; Clifford M Chang; Chelsey K Baldwin; Preneet C Brar; Luc G T Morris; Babak Givi Journal: Surgery Date: 2021-04-08 Impact factor: 4.348