Cancer-sniffing dogs, increased thyroid cancer risk for breast cancer patients and an experimental drug that turns white fat into brown fat were the highlights of three new studies in thyroid issues presented during yesterday’s press conference.
Researchers at the University of Arkansas for Medical Sciences (UAMS) in Little Rock have had success training dogs to sniff out thyroid cancer in human urine and blood samples, according to senior investigator, Donald Bodenner, MD, PhD, chief of endocrine oncology at UAMS.
Dr. Bodenner said the dog’s diagnostic accuracy is only slightly less than that of fine-needle aspiration biopsy but offers the advantage of being noninvasive and inexpensive.
“Scent-trained canines could be used by physicians to detect the presence of thyroid cancer at an early stage and to avoid surgery when unwarranted,” he said, noting that the canine technique is not being currently used for determining patient treatment decisions. The study dog, Frankie, is the first dog trained to differentiate benign thyroid disease from thyroid cancer by smelling human urine.
In the study, 34 patients gave urine samples at their first clinic visit before having biopsies of suspicious thyroid nodules and surgery. Fifteen patients were diagnosed with thyroid cancer and 19 with benign thyroid disease. Blind urine samples were presented by a gloved dog handler to Frankie, who had previously been scent-trained by Dr. Bodenner’s colleague Arny Ferrado, PhD.
The dog’s alert matched the final surgical pathology in 30 of the 34 study samples, Dr. Bodenner said. Frankie correctly identified nearly 87 percent of pathology-proven thyroid cancers, and recognized benign samples almost nine out of 10 times.
UAMS researchers plan to collaborate with Auburn University College of Veterinary Medicine to train two of Auburn’s bomb-sniffing dogs as trained thyroid-cancer sniffing dogs using UAMS samples.
A second study tapped into data found in the National Cancer Institute’s Surveillance, Epidemiology, and End Results 9 (SEER 9) database to look at the relationship between breast cancer and thyroid cancer, a topic that has been controversial.
Jennifer Hong Kuo, MD, assistant professor of surgery at Columbia University, found that breast cancer survivors are at an increased risk of developing thyroid cancer, especially within five years of their breast cancer diagnosis.
Research also showed that compared with patients with breast cancer alone, women who had breast cancer followed by thyroid cancer were younger on average when diagnosed with breast cancer and more likely to have had invasive ductal carcinoma, a smaller focus of cancer, and to have received radiation therapy as part of their breast cancer treatment.
Compared with patients who had only thyroid cancer, breast cancer survivors who developed thyroid cancer were likely to have more aggressive forms of thyroid cancer, but cancers smaller in size. Fewer patients also required radioactive iodine therapy.
“Recognition of this association between breast and thyroid cancer should prompt vigilant screening for thyroid cancer among breast cancer survivors,” said Dr. Kuo, who next plans to look at whether tamoxifen treatment may play a role in increasing thyroid cancer risk.
Finally, results of a new mouse study on the drug GC-1 found that it causes weight loss and fat conversion in mice by speeding up the metabolic rate and converting white fat into calorie-burning brown fat.
Study author Kevin Phillips, PhD, a researcher at Houston Methodist Research Institute said the GC-1 works by activating receptors for thyroid hormone. Researchers tested the drug in hundreds of mice; genetically obese mice lost weight and more than 50 percent of their fat mass in about two weeks, he said. The treated mice also showed antidiabetic effects, such as a sixfold improvement or better in insulin sensitivity. Mice with diet-induced obesity showed similar improvements.
The drug also induced adaptive thermogenesis in fat cells isolated from mice. Cells grown in a dish, as well as tissue samples taken from obese mice, showed evidence of white-fat browning.
“Our data demonstrates that GC-1 is a novel fat-browning agent that may have use in the treatment of obesity and metabolic disease,” said Dr. Phillips.