Dental X-Rays May Be Linked to Benign Brain Tumors (4/10/2012)

Dental X-Rays May Be Linked to Benign Brain Tumors

Study found increased risk, but connection was not conclusive.

By Randy DotingaHealthDay Reporter
TUESDAY, April 10 (HealthDay News) -- People who underwent frequent dental X-rays in the past, before radiation doses were lowered, may be at greater risk of a usually benign form of tumor in the lining of the brain, a new study suggests.

The research doesn't definitely link dental X-rays to the tumors, which affect about 1 percent of people. It's also possible that dental X-rays, which are now given at a lower radiation dose, have nothing to do with the tumors.

Still, the study suggests that dental X-rays could be a risk factor for the tumors, called meningiomas, said study author Dr. Elizabeth Claus, a neurosurgeon at Brigham & Women's Hospital in Boston and a professor of epidemiology at Yale University School of Medicine. The findings suggest that patients should talk to their dentists about the possible dangers of X-rays and be aware of national recommendations regarding their use, she said.

"I do not get the feeling that people are aware of those guidelines," she said. "Many people are having them every six months or every year when the American Dental Association is saying once every two to three years." (That's the recommendation for the patient who's never had a cavity or only a small number of fillings and isn't at increased risk for a cavity.)

Meningiomas affect the lining of the brain and the spinal cord. More than 90 percent are classified as benign, not malignant. But in some cases they can grow to the size of a baseball and disrupt the brain's functioning, leading to vision problems, headaches, hearing and memory loss, and seizures.

Neurosurgeons often try to remove them in the most severe cases.

"They cause problems as soon as they achieve a certain size, because there is no room in the skull to accommodate growth. Any growth that is more than a couple centimeters can result in symptoms," explained Dr. Isabelle Germano, director of the Comprehensive Brain Tumor Program at Mount Sinai School of Medicine in New York City.

Radiation is linked to various types of tumors, including meningiomas. In the new study, researchers sought to determine whether dental X-rays are connected to meningiomas that affect the lining of the brain specifically.

The researchers examined a group of more than 1,400 patients aged 20 to 79 who were treated for the tumors between 2006 and 2011, and compared them to 1,350 similar people who did not develop the tumors. The average age in both groups was about 57.

Those with tumors were more than twice as likely as the others to report having more frequent bitewing X-rays (at any time) and panorex X-rays (especially at a young age).

Bitewing X-rays allow views of the back teeth; patients bite onto a tab during the X-rays. Panorex X-rays show the whole area in and around the mouth from below the nose to the chin.

The design of the study didn't allow the researchers to specify the level of increased risk of a tumor that a person who's had dental X-rays would conceivably face. It does appear, however, that the raised risk would remain low, Claus said.

Overall, more than 92 percent of people in the study reported having had at least one bitewing X-ray.

Dr. Matthew Messina, a Cleveland dentist and spokesman for the American Dental Association, said one weakness of the study is that people's memories about their X-rays are fuzzy. "It's difficult to pin this down," he said, especially without dental records.

Messina added that the amount of radiation in dental X-rays has gone down significantly over the years, thanks to factors such as the improved speed of X-ray film and the advent of digital X-rays.

The study was also observational in nature, meaning it can show an association but not cause-and-effect.

So what should patients do?

Adult patients and parents of child patients should talk to their dentists about X-rays, Germano said. "It's always important to discuss what the X-ray is for and what the advantage is. It's not a good idea to assume that X-rays are a benign procedure," she said.

Messina agreed. "It's always good for patients to talk to their dentists about why they're getting X-rays and what is being done to shield the patient."

Overall, dentists are trying to balance the possible dangers of radiation and the usefulness of X-rays, he said. "We take dental X-rays because we're trying to make sure the person is healthy or trying to diagnose what's wrong with them."

The study appears in the April issue of the journal Cancer.

Source: http://www.womenshealt.gov/new/news/headlines/663600.cfm/

'Freezing' Secondary Breast Cancer Tumors Shows Promise (3/26/2012)

'Freezing' Secondary Breast Cancer Tumors Shows Promise

Preliminary study suggests procedure may buy time for those with advanced disease.
MONDAY, March 26 (HealthDay News) -- In a small and preliminary study, researchers report that they successfully froze secondary tumors in patients with incurable breast cancer.

The findings raise the prospect of a potential new treatment for metastatic tumors in individual patients, although the research is in the very early stages.

"This therapy provides a minimal rate of cancer recurrence and no major complications," study co-author Dr. Peter Littrup, director of imaging core and radiology research at the Karmanos Cancer Institute in Detroit, said in a news release from the Society of Interventional Radiology.

The study is scheduled to be presented Wednesday at the society's annual meeting in San Francisco. Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed medical journal.

"This is a preliminary study, and at this point we're hoping that the evidence could be a stepping stone for a bigger study to look at more patients," Littrup said. "If we can get more data that supports percutaneous cryoablation for metastatic breast cancer, it could be a huge finding."

In percutaneous cryoablation, tiny probes insert pressurized argon gas into tumors and kill them by turning them into balls of ice.

The eight patients in the study had stage 4 metastatic breast cancer, meaning their tumors had spread widely from the breast. The tumors frequently appear in organs such as the liver, lungs, bones and kidneys.

In stage 4, the disease is considered incurable.

"At this point, treatments are considered palliative -- with the intent to keep metastases at bay while hopefully providing individuals more time and improved quality of life, rather than a complete cure," Littrup said.

"Cryoablation as a targeted therapy is beneficial because it can significantly reduce discomfort and incidence of disease," Littrup said. "It's a much better option, we think, than surgery -- especially since many metastatic patients are not candidates for surgery -- and it may potentially lead to longer survival."

The eight patients in the study lived for an average of 46 months, and two survived for at least five years.

Dr. Hannah Linden, an oncology specialist and assistant professor at the University of Washington School of Medicine in Seattle, said it's too early to know whether the treatment works since it hasn't been compared to other therapies.

"Many patients with metastatic breast cancer live a long time with gentle treatments, yet other patients who have relatively resistant tumors do poorly," she said. "While the idea of freezing a tumor to prevent it from growing is feasible and exciting, it is not proven that such an approach actually 'cures' patients or provides long-term benefit."

Although similar treatments target secondary tumors, she added, they "do not address the systemic problem of metastatic cancer. So, while it seems good to 'kill' the metastasis, the cancer is still lurking."

Breast cancer is the most common cancer among women, killing nearly 370,000 people worldwide each year. Approximately 10,000 to 15,000 new cases of stage 4 breast cancer occur in the United States each year, Littrup noted.

Source: http://www.womenshealt.gov/new/news/headlines/663077.cfm/