CLINICAL THYROIDOLOGY FOR PATIENTS
A publication of the American Thyroid Association
Increasing rate of BRAF gene mutation in patients with papillary thyroid cancer
ABBREVIATIONS & DEFINITIONS
Papillary thyroid cancer — the most common type of thyroid cancer.
Cancer-associated genes — these are genes that are normally expressed in cells. Cancer cells frequently have mutations in these genes. It is unclear whether mutations in these genes cause the cancer or are just associated with the cancer cells. The cancer-associated genes important in thyroid cancer are BRAF, RET/PTC and RAS.
BRAF gene — this is gene that codes for a protein that is involved in a signalling pathway and is important for cell growth. Mutations in the BRAF gene in adults appear to cause cancer.
The number of patients with thyroid cancer has been rapidly increasing over the past 10 years. The reason for this increase in thyroid cancer is still unclear. Mutations in certain cancer-associated genes can be seen in thyroid cancer. In particular, mutations in the BRAF gene are seen in a large percentage of papillary cancers. This study looked at presence of mutations in the BRAF gene in papillary cancer over the last 15 years.
THE FULL ARTICLE TITLE:
Mathur et al. Higher rate of BRAF mutation in papillary thyroid cancer over time: A single-institution study Surgical results of thyroid nodules according to management guideline based on BRAF-V600E mutation status. Cancer. Mar 15, 2011[Epub ahead of print] doi:10.1210/jc.2010-1082.
SUMMARY OF THE STUDY
The authors studied 628 patients with papillary cancer seen between 1991–2005. The presence of BRAF mutations were examined in the pathology specimens from these patients and the results separated into the following 5-year periods: 1991–1995, 1996–2000 and 2001–2005. Age at diagnosis, sex, ethnicity and cancer stage were not different between these 3 groups. The frequency of BRAF mutation was higher (88%) in patients diagnosed between 2001–05 as compared to those diagnosed between 1991–1995 (51%) or 96–2000 (43%).
WHAT ARE THE IMPLICATIONS OF THIS STUDY?
This study shows that the frequency of mutations in the BRAF gene in patients with papillary thyroid cancer increased during the last 15 years. This suggests that an increase in BRAF gene mutation may be a cause for the increasing number of patients with papillary thyroid cancer. It is not known what is the cause for this increase in BRAF gene mutation. In general, radiation exposure does not appear to increase the frequency of BRAF gene mutation. Current research is looking at toxic chemicals our environment as potential causes.
—Jamshid Farahati, MD
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