Abstract
Despite continued debate, the BRAF V600E mutation is a valuable prognostic factor in thyroid carcinoma. We aimed to use immunohistochemistry to detect BRAF (VE1), estrogen receptor (ER) and progesterone receptor (PgR) expression in thyroid tumors. Surgical specimens from 59 cases of thyroid Papillary carcinoma, 3 cases of thyroid follicular carcinoma, 3 cases of poorly differentiated thyroid carcinoma and 4 cases of undifferentiated thyroid carcinoma were collected between 2004 and 2014 at Showa University Hospital. As a benign lesion control, we used specimens from 46 cases of adenomatous goiter. Specimens were immunostained for BRAF (VE1), ER and PgR. The cutoff immunostaining intensity value for a positive BRAF (VE1) specimen was ≥ 2. ER and PgR were deemed positive if the Allred score was ≥ 3. The median age of the 59 patients with Papillary carcinoma was 58.0 years (range, 22-87 years), and the specimens were from 14 males and 45 females. The number of Papillary carcinoma specimens that were positive for BRAF (VE1), ER and PgR was 40 (68%), 2 (3%) and 32 (54%), respectively. For adenomatous goiter, positive scores were detected for BRAF (VE1), ER and PgR in 0 (0%), 1 (2%) and 12 specimens (26%), respectively. In patients with Papillary carcinoma, there was no difference in the number of BRAF (VE1)-positive and -negative specimens, according to sex or tumor diameter, although there were significantly more BRAF (VE1)-positive specimens from people ≥ 45 years, compared to those ＜ 45 years old. No BRAF (VE1)-positive expression was detected in adenomatous goiter, and BRAF (VE1) expression was specific for Papillary carcinoma. Our study suggests that BRAF (VE1) immunoexpression may be a useful marker for BRAF molecular targeted therapy for Papillary carcinoma in the near future.
