The data show a higher rate of inherited MTC than previously described, although MEN2A was found to be the most common inherited form of MTC, the same as in earlier studies.
All patients diagnosed with medullary thyroid carcinoma (MTC) should undergo RET mutation analysis to exclude familial disease - multiple endocrine neoplasia (MEN)-2A and -2B and familial medullary thyroid carcinoma (FMTC).
Four children were at risk of being carriers of a mutated gene, as their fathers had histologically proven MTC and had tested positive for the mutation at codon 618 on exon 10 of the RET proto-oncogene.
These clinical forms differ in many ways, as s-medullary thyroid carcinoma cases are RET-negative in the germline and are typically diagnosed later than medullary thyroid carcinoma in MEN2 patients.
Overall, our results showed that RAS mutations were present in 68.0% (17 of 25) of the RET-negative MTC and in only 2.5% of the RET-positive MTC (P < 0.0001), suggesting that activation of the protooncogenes RAS and RET represents alternative genetic events in sporadic MTC tumorigenesis.
Genetic study of the RET proto-oncogene has modified the management, treatment, and prognosis of medullary thyroid carcinoma (MTC), multiple endocrine neoplasia 2A (MEN 2A), for patients with less advanced tumor stages.
Germline mutations in the gene encoding the RET receptor tyrosine kinase are found in the vast majority of MEN 2 patients and somatic RET mutations are found in a subset of sporadic MTC.
In addition, patients with medullary thyroid cancer with RET mutations showed a 5.82-fold higher risk of death by the disease than without a RET mutation.
We sought to determine whether total thyroidectomy in asymptomatic young members of kindreds with MEN-2A who had a mutated allele of the RET proto-oncogene could prevent or cure medullary thyroid carcinoma.
The recognition of RET proto-oncogene mutations by genetic sequencing has allowed us to differentiate hereditary from sporadic MTC, so that it is now possible to identify and treat children at risk for this disease before development of metastasis.
Medullary thyroid carcinoma (MTC) is a characteristic tumor occurring in individuals with multiple endocrine neoplasia type 2 who carry germ-line mutations in RET (rearranged during transfection).
In this study, we collected clinical and molecular data from 554 patients with surgically confirmed MTC from 176 families with MEN2 in 18 different Brazilian centers to compare the type and prevalence of RET mutations with those from other countries.
Not one statistically significant dose-response relationship was identified between any RET variant (wildtype vs RET heterozygotes vs homologue RET homozygotes) and patient age at MTC diagnosis, gender, primary tumour size, extrathyroidal extension, numbers of involved and removed lymph nodes, or distant metastasis.
We describe the RETG533C mutation in exon 8 of the RET in two unrelated female index patients, with MEN2A phenotype, consisting of pheochromocytoma which was the presenting feature and medullary thyroid carcinoma.
In this review we emphasize the main RET mutations in syndromic and non syndromic forms of MTC, and focus on the importance of RET genetic screening for early diagnosis and management of MTC patients, based on American Thyroid Association guidelines and genotype-phenotype correlation.
This family of 11 individuals with familial MTC type of MEN 2A syndrome demonstrated the moderate risk RETp.Val804Met (protein valine at residue 804 replaced by methionine) genetic mutation, with 2 of the relatives presenting with dermal hyperneury, cutaneous lesions classically described in MEN 2B syndrome, and 1 relative also showing multiple sclerotic fibromas, a cutaneous manifestation of PTEN (phosphatase and tensin homologue) hamartoma-tumor syndrome.
Medullary thyroid carcinoma (MTC) is characterized by proto-oncogene RET mutations in almost all hereditary cases as well as in more than 40% of sporadic cases.
Now, available mouse models bearing mutations of RET or other genes, which spontaneously develop MTC, promise to improve preclinical evaluation of activity of targeted compounds.