High percentages of BRAFV600E alleles resulted in poorer outcomes among patients with papillary thyroid carcinoma, according to data published in The Journal of Clinical Endocrinology & Metabolism.
“In the present study, we examined the association between the percentage of BRAFV600E alleles and both the clinicopathological parameters and disease outcome in a large series of [papillary thyroid carcinomas], demonstrating that a high percentage of mutant BRAF alleles strongly predict a reduced disease-free survival,” the researchers wrote.
The study included 168 patients who underwent total thyroidectomy for papillary thyroid carcinoma at the Ospedale San Paolo and Fondazione IRCCS Ca’ Granda in Milan, Italy, between 1994 and 2010.
Patients were randomly and consecutively selected for genotyping for BRAFV600E alleles using BigDye Terminator sequencing and pyrosequencing, the researchers wrote.
They said BRAFV600E prevalence was higher when using pyrosequencing rather than BigDye Terminator sequencing (53.6% vs. 36.9%). In patients with papillary thyroid carcinoma who were positive for BRAFV600E alleles, the percentage of mutant alleles ranged from 5.1% to 44.7% of the total BRAF alleles (median, 20.6%).
BRAFV600E allele percentage related directly with age at diagnosis (P=.039) and tumor volume (P<.001), the researchers wrote.
According to the data, disease outcome was predicted by the following: percentage of BRAFV600E alleles (P=.014), tumor volume (P=.012) and lymph node metastasis (P=.008).
After a median of 5.1 years follow-up, disease recurred among 22.8% of patients. Recurrence was 2.1 times more frequent among BRAFV600E-positive patients compared with BRAFV600E-negative patients (33.3% vs. 15.6%; P=.04), the researchers wrote.