Meds news

Researchers have succeeded in freezing away breast and prostate tumors in a small number of patients, opening a promising door to a new generation of cancer treatments.

In two separate studies to be presented Tuesday at the Society of Interventional Radiology’s annual meeting in Tampa, Fla., research teams reported success using cryotherapy to freeze and destroy malignant tumors. In the prostate cancer patients, cryotherapy occurred after surgery, while the women in the breast cancer study had no surgery.

Cryotherapy has been used in different oncology settings in the past, but these studies were innovative in that they used multiple probes to kill the tumor and/or MRI to guide the procedure.

The prostate study involved four patients whose cancer had recurred after prostate removal. All had had some radiation treatment in addition to surgery.

“We found a subgroup of patients . . . where we have basically exhausted everything we can do for them,” said study lead author Dr. David A. Woodrum, interventional radiologist at the Mayo Clinic in Rochester, Minn.

Two of the prostate cancer patients underwent cryoablation, which uses very low temperatures to kill the tumor, while the other two underwent thermal therapy, which uses high temperatures to achieve the same goal. This approach was also successful.

“We used magnetic resonance imaging to place somewhere between one and three probes [basically small needles] into the tumor and then we perform the ablation,” Woodrum said. “We don’t have a radiation risk, so we can use sequential imaging approximately every six to 10 seconds to image the area and see either the tissue heating up from the laser or the tissue freezing from the cryoablation.”

The imaging allowed extra precision so that adjacent organs, such as the bladder and urethra, were less likely to be damaged.

“The MR imaging is helpful and innovative because it has been demonstrated by some investigators to image the malignant prostate cancer better than ultrasound,” said Dr. K. Scott Coffield, professor of surgery at Texas A&M Health Science Center College of Medicine and a urologist-oncologist with Scott & White Healthcare in Temple.

But the technique may not work with very small masses, he cautioned.

Traditionally, cryoablation to treat prostate cancer has been paired with ultrasound, he added.

The breast study involved 13 women who had refused surgery for breast cancer and underwent cryotherapy to eliminate their tumors instead.

Biopsies performed after the procedures were negative, and the women did not need follow-up surgery, according to the study authors, from Karmanos Cancer Institute and Wayne State University in Detroit. In other words, they were able to keep their breast.

Again, the investigators used probes inserted through the skin to deliver the cold gas intended to kill the cancer. The probes were guided using ultrasound alone or ultrasound plus computed tomography.

The women were followed up with MRI scans and clinical exams.

“We’ve had problems with this type of therapy in the past with the kill zone, but now, using multiple probes you can extend that,” said Dr. Debra Monticciolo, professor of radiology at Texas A&M Health Science Center College of Medicine and vice chair of research in radiology and chief of breast imaging at Scott & White in Temple. “That’s a smart idea. The concept is good, but we need a bigger study with longer follow-up. It takes a while for a couple of tumor cells left behind to gather enough steam to be noticed,” she added.

“This is investigative, but it shows a lot of promise,” Monticciolo said.

SOURCES: David A. Woodrum, M.D., Ph.D., interventional radiologist, Mayo Clinic, Rochester, Minn.; K. Scott Coffield, M.D., professor, surgery, Texas A&M Health Science Center College of Medicine, and urologist-oncologist, Scott & White, Temple, Texas; Debra Monticciolo, M.D., professor, radiology, Texas A&M Health Science Center College of Medicine, and vice chair, research, radiology, and chief, breast imaging, Scott & White, Temple, Texas; study abstracts, Society of Interventional Radiology annual meeting.

Tiny electric shocks to the throat may help stroke victims overcome disabling swallowing difficulties, a small British study suggests.

Up to three-fourths of people suffering strokes are left drooling or choking on foods and drinks because brain areas involved in swallowing have been wiped out. Many never recover, and some require a feeding tube.

“Improving swallowing in patients with stroke is likely to have one of the highest impacts on their quality of life,” Dr. Shaheen Hamdy of the University of Manchester, who led the new research, told Reuters Health in an e-mail.

Hamdy is studying whether stimulating nerves in the throat with small electrical jolts can somehow jump-start the areas of the brain damaged by the stroke.

In his new report, published in the journal Gastroenterology, he tested the idea both in stroke victims with swallowing difficulties and in healthy people who had their brains stimulated with a magnetic field to mimic a stroke.

First, the 28 stroke patients had a small tube inserted into their throats. Hamdy’s team then randomly assigned half of the patients to receive electrical shocks–mild enough that they weren’t uncomfortable–for 10 minutes on three consecutive days. The other half had the tube inserted with no current.

A few days later the researchers used X-rays to track how liquid went down the patients’ throats as they swallowed.

About two-thirds of the patients choked on the liquid before getting shocked. After the electric stimulation, that percentage fell to about a quarter. There was no improvement among those who didn’t get shocked.

Swallowing also became easier after stimulation, and the patients left the hospital an average of five days earlier.

However, Hamdy emphasized that the study was small and preliminary, and that not all patients improved. “This is not a panacea,” he said.

But he added that if the findings are confirmed in the larger study he is currently working on, the treatment could benefit a lot of patients.

“The technology is fairly easy to deliver, quick to apply and requires little or no compliance from the patient,” he said. “This makes it eminently suited to stroke patients.”

Today, most treatment consists of modifying a stroke victim’s diet or teaching the patient different ways of chewing. But only a minority of patients benefit from such exercises, experts say. Those who don’t end up with a high risk of developing pneumonia, because foreign particles fall into their lungs when they choke.

While the new technology might potentially benefit these patients, some experts say it faces significant hurdles.

“In terms of practicality, I can’t see this being something you run out and do on patients,” said Giselle Mann, who has worked with swallowing disorders and rehabilitation for some 25 years.

Mann, of the University of Florida, said she had been a research subject herself in one trial and thought the insertion of the throat tube was uncomfortable, if not exactly painful. Frail, elderly people — or their families — may not be ready to embrace such an invasive treatment after going through the ordeals of a stroke.

“Swallowing a 3.2-millimeter catheter is no mean feat for anyone,” Mann said, adding that the small number of people in the study also warrants caution.

Still, she found the prospect of expediting the brain’s recovery after a stroke fascinating. “He might be onto something really exciting here,” she said, referring to Hamdy’s research.

How the process speeds recovery is still murky. In an attempt to understand it better, Hamdy and colleagues produced a virtual “stroke” in 13 healthy people by turning on a magnetic coil placed over their skulls.

Repetitive transcranial magnetic stimulation, or rTMS as this technique is better known, messes with the electrical activity of brain cells and can be used to turn them on or off; although it sounds dramatic, it has no known side effects when used briefly in the lab.

With the magnet, Hamdy’s team slowed the activity in brain areas controlling throat muscles, thus mimicking the effects of a stroke. They found a corresponding decrease in throat muscle activity and in the number of correctly timed swallows. But if the subjects were stimulated electrically with the throat tube, these effects were completely abolished.

Electric stimulation of the throat “seems to act by increasing the size of the regions in the brain controlling swallowing, which might actually be how stroke patients spontaneously recover swallowing anyway,” said Hamdy. “We seem to be accelerating this brain ‘plasticity’ process, with effects in both the damaged and undamaged sides of the brain.”

So far, Hamdy has found no negative side effects of the treatment. His university continues to develop the technology, which it plans to market within two years.

SOURCE: Gastroenterology.

A low-carbohydrate diet helps people shed as many pounds as a low-fat diet plus the weight-loss drug orlistat does, and the low-carb plan may be better at helping lower blood pressure, researchers report.

Their study, published in the Jan. 25 issue of the Archives of Internal Medicine, found that both diets helped participants lose almost 10 percent of their body weight.

“Weight loss was similar but substantial in both groups we studied, but blood pressure improved more in the low-carb dieters,” said study author Dr. William Yancy Jr., an associate professor of medicine at Duke University Medical Center and a staff physician at the Department of Veterans Affairs Medical Center in Durham, N.C.

“There are options out there. Pick a diet you think you could stick to better, and work with your physician to help you target the right intervention for you,” he advised. Two other studies in the same issue of the journal look at the effectiveness of the anti-hypertension DASH diet and a physician-supervised plan.

Obesity is a significant contributor to many illnesses, including heart disease, stroke, diabetes and many cancers, according to an editorial in the same journal by Dr. Robert Kushner of Northwestern University’s Feinberg School of Medicine. More than one-third of American adults are obese, and the incidence of obesity has gone up 140 percent over the past decade, Kushner notes.

Yancy’s study included 146 overweight or obese adults who were randomly assigned to a low-carbohydrate diet or orlistat with a low-fat diet. The average age of the study participants was 52 and the average body-mass index was 39 (30 and over is considered obese). Orlistat is marketed as Xenical, a prescription medication, and Alli, available over the counter.

The low-carb diet began with a carbohydrate intake of less than 20 grams of carbohydrates a day. The group taking orlistat received a 120-milligram dose of the drug three times daily and got less than 30 percent of their calories from fat.

Over 48 weeks, the low-carbohydrate group lost 9.5 percent of their body weight, while the orlistat group lost 8.5 percent. “Good” cholesterol (HDL) and triglyceride levels improved in both groups. LDL, or “bad” cholesterol, was only reduced in the orlistat group. Insulin and glucose markers improved only in the low-carb group, and there was a significant drop in blood pressure in the low-carb group compared to the orlistat group — systolic blood pressure (the top number) dropped by 5.9 mm Hg on the low-carb diet vs. 1.5 mm Hg for the orlistat group. Similar reductions were seen for diastolic blood pressure.

Yancy said the blood pressure and cholesterol drops might have been even more impressive if people had stayed on their medications, but as they lost weight and normalized these readings, the doctors took them off blood-pressure and cholesterol drugs.

Two other studies in the same issue of the journal looked at the effects of the DASH diet and a physician-supervised plan.

Researchers compared the DASH (Dietary Approaches to Stop Hypertension) diet alone and in combination with exercise and weight management on blood pressure. The researchers found that combining the DASH diet with weight management and exercise resulted in a 16.1 mm Hg drop in systolic blood pressure compared to 11.2 mm Hg on the DASH diet alone. Additionally, those in the exercise, weight management and DASH plan lost an average of 19 pounds over four months vs. less than one pound for the DASH diet alone.

The third study compared an Internet weight-management program with a physician-managed program for extremely obese people that included a liquid diet component, followed by a structured diet, behavioral counseling and diet medications. The more intensive intervention was more successful with 31 percent losing more than 5 percent of their body weight, compared to just 9 percent of the Internet group.

“There are many paths to weight loss,” said registered dietitian Karen Congro, director of the Wellness for Life Program at The Brooklyn Hospital Center in New York City. What often makes the difference in whether or not a diet is successful, she said, is whether or not there’s a counseling and support component to the plan.

And, she said, these studies show that you don’t necessarily need to get to your “ideal body weight” to make substantial improvements to your health. Losing 5 percent to 10 percent of your body weight can make positive changes in blood pressure, cholesterol and glucose control.

“If it can make you a healthier person, then a diet is a success,” said Congro.

SOURCES: William Yancy Jr., M.D., M.H.S., associate professor, medicine, Duke University Medical Center, and staff physician, Department of Veterans Affairs Medical Center, Durham, N.C.; Karen Congro, R.D., C.D.N., director, Wellness for Life Program, The Brooklyn Hospital Center, New York City

Researchers say they’ve spotted a new genetic risk factor for Parkinson’s disease, as well as a link between the illness and two other factors, metabolism and vitamin B6.

“Our study reveals the interaction of genetic and environmental factors such as dietary habits in the pathogenesis of Parkinson’s disease,” Dr. Matthias Elstner of Germany’s Ludwig-Maximilians-Universitat Munich, said in a news release from the German Research Center for Environmental Health.

Elstner is lead author of a new study published in the January issue of the journal Annals of Neurology.

The researchers studied neurons to understand how genes change their activity due to Parkinson’s disease. They found a gene that seemed important and looked for it in 1,200 Parkinson’s patients and 2,800 healthy people. It was discovered that a gene variant boosted the risk of the disease.

According to the study authors, the gene variant may affect the activity of an enzyme in the brain, called pyridoxal kinase (PDXK). The role of PDXK is to convert vitamin B6 from dietary sources into an active form that is required for the production of dopamine, a neurotransmitter that has long been known to be associated with Parkinson’s disease.

“Although this variant is responsible for only a slight contribution to the overall risk for Parkinson’s disease, our findings could aid in developing individualized therapies,” Elstner said.

SOURCE: German Research Center for Environmental Health