The genetic mutation BRAF V600E is significantly associated with increased cancer-related death among patients with papillary thyroid cancer, according to a study in the Journal of the American Medical Association (April 10, 2013, Vol. 309:14, pp. 1529-1530).
However, because overall mortality with papillary thyroid cancer is low and the association was not independent of tumor characteristics, how to use this information to manage mortality risk in thease patients is unclear, noted the study authors, from the Johns Hopkins University School of Medicine.
The overall five-year patient survival rate for papillary thyroid cancer is 95% to 97%. A major clinical challenge is how to reliably distinguish patients who need aggressive treatments to reduce mortality from those who do not. The issue has become even more challenging given the high annual incidence of the cancer.
For this study, Mingzhao Xing, MD, PhD, and colleagues examined the association between the BRAF V600E mutation and papillary thyroid cancer-related mortality. The study included 1,849 patients (1,411 women, 438 men) with a median age of 46 years and an overall median follow-up time of 33 months after initial treatment at 13 centers in seven countries between 1978 and 2011.
The overall prevalence of BRAF V600E was 46%, they reported. There were 56 papillary thyroid cancer-related deaths among the 1,849 patients, representing an overall mortality of 3%. Among these deaths, 80% were positive for BRAF V600E. The overall mortality of all papillary thyroid cancer cases was 5% in BRAF V600E-positive patients versus 1% in mutation-negative patients.
When the aggressive tumor features of lymph node metastasis, extrathyroidal invasion, and distant metastasis also were included in the model, the association of BRAF V600E with mortality for all papillary thyroid cancers was no longer significant, the authors concluded.
