J Endocrinol Invest  1999 Nov;22(10):781-9 

Ras mutations are uncommon in sporadic thyroid cancer in children and young
adults.

Fenton C, Anderson J, Lukes Y, Dinauer CA, Tuttle RM, Francis GL.

Department of Pediatrics, F. Edward Hebert School of Medicine, Uniformed
Services University of the Health Sciences, Bethesda, MD 20814, USA.

Mutations in the ras genes (H-ras, K-ras, and N-ras) occur in 10-15% of all
human cancers, and commonly arise from single base substitutions at codons 12,
13, or 61. Although ras mutations have been found in adult thyroid cancers, they
were absent from the two studies which examined childhood thyroid cancers. Both
studies included only children with radiation induced thyroid cancer, and it
remains unclear if ras mutations occur in children without radiation exposure.
To answer this question, we examined archival tissue blocks from 31 children
with papillary thyroid cancer (PTC) 4 with follicular thyroid cancer (FTC), 2
with medullary thyroid cancer (MTC), and 1 with lymphoma (LYM). Only 1 patient
with PTC had previous radiation exposure. Genomic DNA was extracted and used for
PCR amplification of the ras genes. The PCR products were analyzed by
oligospecific hybridization for mutations at codons 12, 13, and 61. Two of the
PTCs (6.5%) contained ras mutations. Both patients had class II disease and no
history of previous radiation exposure. One patient subsequently developed bone
and lung metastases. The patient with lymphoma also had a ras mutation (N-61),
but ras mutations were absent from all FTC and MTC. These results suggest that
ras mutations are uncommon in spontaneous childhood thyroid cancer, but occur
with a frequency similar to that found in previous reports of adult
differentiated thyroid cancers. The number of subjects was too small to
determine if ras mutations are more common in patients with aggressive papillary
thyroid cancer.

PMID: 10614528 [PubMed - indexed for MEDLINE]