Figure 3.

Aberrantly methylated genes frequently observed in papillary thyroid cancer. PBC, peripheral blood cells. We detected 25 genes that were hypermethylated (β > 0.25) in at least three of 14 papillary thyroid cancer samples, but not methylated (β < 0.2) in 10 normal samples. Among the 14 papillary cancer samples, 11 showed aberrant methylation in three or more genes, whereas the other three samples had no aberrant methylation. Purple, tumor size; brown, number of metastatic lymph nodes >3; gray, distant metastasis(+); green, age over 45 years old; pink, female; pale blue, stage III or IV; red, recurrence (+); orange, BRAF mutation(+); blue, RAS mutation (+). The two samples with recurrence (red) had no aberrant methylation (P = 0.03, Fisher's exact test). BRAF/RAS oncogene mutations were all observed in methylation(+) samples (P = 0.03, Fisher's exact test).