The mutation, called BRAF V600E, is a genetic alteration in the BRAF oncogene, a modified gene believed to cause cancer. The new research is reported in the September issue of the “Annals of Surgery.”
Past studies have shown that the mutation frequently occurs in the most common type of thyroid cancer, conventional papillary thyroid cancer or PTC, but this is the largest study to classify thyroid cancer by cell structure subtype and to show that the mutation is significantly associated with cancer recurrence after treatment, according to the research team.
The findings come at an important time as both the incidence of thyroid cancer and the number of patients who die from the disease is increasing in the United States. More than 33,000 new cases of thyroid cancer are expected to be diagnosed in 2007, according to the National Cancer Institute.
Most patients diagnosed with thyroid cancer have small, localized PTC but may receive aggressive treatment because their risk of recurrence and death cannot be reliably predicted prior to surgery, the study authors noted.
“There is a pressing need to identify a reliable preoperative approach for stratifying patients according to risk of thyroid cancer recurrence and death,” said lead author Electron Kebebew, MD, who is an assistant professor of surgery and endocrine surgeon at the University of California, San Francisco and a research scientist with the UCSF Comprehensive Cancer Center.
“This study shows that a particular mutation is a reliable indicator, and testing for the mutation may be useful for selecting initial therapy, determining the need for and extent of surgery, as well as the need for ongoing monitoring and follow-up care,” he emphasized.
In the study, the researchers examined tumor samples from 314 patients with thyroid cancer (245 with conventional PTC, 73 with follicular thyroid cancer and 29 with the follicular variant of PTC) to determine the presence of BRAF V600E and its association with factors such as tumor size, tumor stage, and patient outcome.
They found the mutation in 51 percent of patients with conventional PTC, in 1 percent of patients with follicular thyroid cancer, and in 24.1 percent of patients with follicular variant PTC.
In conventional PTC and follicular variant PTC, the mutation was significantly associated with older age, larger tumor size, and recurrent and persistent disease. These patients also showed a trend toward a higher rate of cancer formation in the lymph node due to metastasis (the transfer of tumor cells from one organ or part of the body to another organ or part) and higher stage cancer.
In patients with conventional PTC, the mutation was associated with older age, lymph node and other metastasis, and was an independent risk factor for recurrent and persistent disease. Median follow-up time of all patients in this study was six years.
Kebebew explained that identification of the mutation in patients with thyroid cancer could be very useful in a variety of ways. For example, patients with the mutation may be candidates for a more aggressive approach to surgery, such as removing the central lymph node along with the diseased thyroid, to avoid the possibility of metastasis following surgery. BRAF V600E testing could also be useful for deciding between low- or high-dose radioiodine ablation therapy.
“Advances in molecular biology techniques have improved our understanding of the genetic changes in cells that lead to the formation of cancer and have provided opportunities for identifying disease biomarkers like this mutation,” added Kebebew. “It is critical to continue the drive to discover reliable biomarkers so we can better identify, treat and cure cancer.”
The study was funded by the Robert Wood Johnson Foundation, the American Cancer Society Research Scholars Grant, Hellman Family Grant, the University of California Cancer Research Committee and the National Institutes of Health.
Study co-investigators were Julie Weng, BS; Juergen Bauer, MD; Gustavo Ranvier, MD; Orlo Clark, MD; Quan-Yang Duh, MD; Daniel Shibru, MD; Boris Bastian, MD, and Ann Griffin, PhD, all of UCSF.
UCSF is a leading university that advances health worldwide by conducting advanced biomedical research, educating graduate students in the life sciences and health professions, and providing complex patient care.
Vanessa deGier | EurekAlert!
Modern genetic sequencing tools give clearer picture of how corals are related
17.08.2017 | University of Washington
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.
As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
17.08.2017 | Physics and Astronomy
17.08.2017 | Earth Sciences
17.08.2017 | Physics and Astronomy