Sunday, April 15, 2012

Dental X-rays increase Tumors inside skull


From Medscape Medical News > Oncology

Dental X-Rays Linked to Tumors Inside Skull

Sandra Yin
     
     
    April 10, 2012 — Early or repeated exposure to dental x-rays appears to increase the risk for meningioma, the most commonly reported primary brain tumor in the United States, according to a study published online April 10 in Cancer.
    The study reveals a statistically significant increased risk for meningioma in people who underwent bitewing or panoramic x-rays.
    "The findings presented here are important, because dental x-rays remain the most common artificial source of exposure to ionizing radiation for individuals living in the United States," the researchers report.
    According to lead author Elizabeth Claus, MD, PhD, professor and director of medical research at the Yale University School of Public Health in New Haven, Connecticut, and attending neurosurgeon at the Brigham and Women's Hospital in Boston, Massachusetts, "the study presents an ideal opportunity in public health to increase awareness regarding the optimal use of dental x-rays, which unlike many risk factors is modifiable."
    Most Meningiomas Are Benign
    Meningiomas are tumors that arise from the meninges, which are membranes that surround the brain and spinal cord, Derek Johnson, MD, a neurologist who specializes in neuro-oncology at the Mayo Clinic in Rochester, Minnesota, told Medscape Medical News. He was not involved in the study. Although technically not brain tumors, they occur inside the skull and can push inward on the brain from the outside. The vast majority (90%) are pathologically benign, he said. Some 170,000 people in the United States have been diagnosed with these tumors.
    If small meningiomas are found but are not causing any symptoms, usually observation is all that's necessary. "Finding a meningioma does not necessarily mean that it must be treated," said Dr. Johnson.
    But if the tumor grows over time or causes symptoms, surgery or radiation therapy, either fractionated or with techniques such as Cyberknife or Gamma Knife, can be considered, he said.
    Largest Study to Date
    The researchers set out to explore the relation between dental x-rays, which are the most common modifiable source of ionizing radiation, and the risk for intracranial meningioma.
    The population-based case–control study compared 1433 patients with intracranial meningioma from 4 states with a control group of 1350 people with similar traits who had not been diagnosed with a meningioma.
    This study is the largest of its kind to explore the effects of relatively common dental x-rays, according to the researchers. Most previous data came from studies that looked at the effects of high-dose single exposures such as atomic bombs, or a small number of high-dose exposures like radiation therapy, the researchers note.
    Over a lifetime, patients with meningioma were more than twice as likely as control subjects to report having had a bitewing exam, which uses an x-ray film held in place by a tab between the teeth, the researchers found.
    Regardless of age, more frequent bitewing films were associated with increased risk. People who had meningiomas were 1.4 to 1.9 times more likely than control subjects to have received bitewing exams yearly or more often.
    Bitewing x-rays are relatively common. More than 92% of the population studied had undergone one.
    I think this is the best and most conclusive evidence to date.
    "I think this is the best and most conclusive evidence to date that low-dose repeated exposure — the kind of thing we come into contact with relatively regularly in our day-to-day life — is likely a true risk factor for this particular tumor," Dr. Johnson told Medscape Medical News.
    The less common panorex exams, which offer a 2-dimensional panoramic view of all a person's teeth and surrounding bones, were associated with a notably higher risk for meningioma among people screened when young and among those who had the exams yearly or more often. People who reported undergoing such x-rays when they were younger than 10 years of age had a 4.9 increase in the risk of developing the brain tumors. However, Dr. Johnson noted that a small sample size (22 cases) led to some instability in the odds ratio, resulting in a wide confidence interval (1.8 to 13.2). Less than half (47 percent) of case and control subjects had ever undergone a panorex exam.
    Another expert said that the study highlights the dangers posed by dental x-rays. "The importance of this study is that it shows that this is not a procedure with zero risk," said Keith L. Black MD, chair and professor of the Department of Neurosurgery, director of the Maxine Dunitz Neurosurgical Institute, and director of the Johnnie L. Cochran, Jr. Brain Tumor Center at Cedars-Sinai Medical Center in Los Angeles, California. "As a general rule, we need to be more concerned about x-ray exposure, particularly in the younger population," he explained.
    When Possible, Avoid Fishing Expeditions
    If there is no evidence of a problem, such as a cavity or the need for a root canal that might warrant further exploration, Dr. Black advises against x-ray fishing expeditions. For more than 20 years, his dentist has asked him after his twice-yearly dental cleanings whether he wants x-rays. Without fail, he declines. "If I have no complaints and they see no cavities, I don't see the point in getting the x-rays, so I refuse," he said.
    Patients and parents should have conversations with their dentists about the risks and benefits of dental x-rays, he said, so they can make the most informed, intelligent decisions about when to get them. Dental x-rays should not be indiscriminately used as a yearly screening test for patients. "They should use them only when they're only critically necessary," said Dr. Black.
    Cancer. Published online April 10, 2012. Abstrac
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    ?Statins use in Healthy Male with Raised Cholesterol


    From Heartwire

    Should Statins Be Used in Primary Prevention? JAMA Gets in on the Debate

    Michael O’Riordan
    April 10, 2012 (Baltimore, Maryland and San Francisco, California)— Differing opinions on the use of statins in primary prevention make the pages of one of the leading medical journals this week, with the Journal of the American Medical Association (JAMA) the latest in a line of professional and mainstream media outlets getting in on the contentious topic. Introduced by the JAMA editors to encourage discussion and debate, the inaugural "dueling viewpoints" kicks off its new series by considering the clinical question of whether or not a healthy 55-year-old male with elevated cholesterol levels should begin taking the lipid-lowering medication.
    The two "combatants" in the clinical duel will also be familiar, having previously debated the topic in the pages of the Wall Street Journal, as well as on theheart.org. For Drs Rita Redberg and William Katz (University of San Francisco, California), who argue that healthy men should not take statins, there are other effective means to reduce cardiovascular risk, including dietary changes, weight loss, and increased exercise.
    "These strategies are effective in increasing longevity and also result in other positive benefits, including improved mood and sexual function and fewer fractures," they write. "Although these strategies are challenging, prescribing a statin may undermine them. For example, some patients derive a false sense of security that because they are taking a statin they can eat whatever they want and do not have to exercise."
    In their counterpoint, Drs Michael BlahaKhurram Nasir, and Roger Blumenthal (Johns Hopkins Ciccarone Center for the Prevention of Heart Disease, Baltimore, MD) agree that the cornerstone of treatment for patients with elevated cholesterol levels will always be diet and exercise but that statins can be a "critical adjunct for those identified to be at increased coronary heart disease risk." The Johns Hopkins physicians argue that there is no logic in waiting for an MI to occur before starting statin therapy and that if clinicians are unsure of the risk of seemingly healthy patients with elevated cholesterol levels, the use of coronary artery calcium (CAC) screening can help.
    "The CAC scan is a helpful tool that enables clinicians to direct statin treatment at the disease (coronary atherosclerosis) that they propose to treat and illustrates the concept of risk-based, individualized decision making," write Blaha, Nasir, and Blumenthal. "Statin therapy would not be recommended if a CAC scan revealed a score of 0."
    In their viewpoint, they point to data from WOSCOPS and AFCAPS/TexCAPS showing reductions in MI and other coronary events in the primary-prevention setting. However, they argue that the debate over cholesterol therapy needs to be rephrased, because doctors should never treat elevated cholesterol levels in isolation but instead aim to provide therapy to the highest-risk patients most likely to benefit.
    For Redberg and Katz, however, the data simply do not support the use of statins in the 55-year male patient with normal blood pressure and no family history of disease but with elevated cholesterol levels. They point to a recent meta-analysis in healthy but high-risk men and women showing no reduction in mortality with statin therapy, as well as a recent Cochrane review showing similar results. Moreover, Redberg and Katz highlight the adverse effects associated with statins, including cognitive defects and diabetes.
    "For every 100 patients with elevated cholesterol levels who take statins for five years, a myocardial infarction will be prevented in one or two patients," they write. "Preventing a heart attack is a meaningful outcome. However, by taking statins, one or more patients will develop diabetes and 20% or more will experience disabling symptoms, including muscle weakness, fatigue, and memory loss."

    HPV4 Vaccine Adverse events in Young Women


    From Medscape Medical News

    Adverse Events Minor in Young Women Taking HPV4 Vaccine

    Ricki Lewis, PhD
    April 6, 2012 — Adverse events from initial human papillomavirus vaccination (HPV4; Gardasil, Merck) are mild, according to a studypublished online January 9 in the Journal of Women's Health. Results also indicate that older women understand the role of the virus in elevating cervical cancer risk better than younger women.
    HPV4 vaccination began in the United States in girls and women aged 9 to 26 years in June 2006. The manufacturer's direct-to-consumer marketing campaign, extensive media coverage, and efforts in some states to require vaccination for public school admission spread awareness of the vaccine and of the ability of certain subtypes of HPV to cause cervical cancer.
    Data on adverse events have been limited to clinical trial results and reports to the US Food and Drug Administration and the US Centers for Disease Control and Prevention's Vaccine Adverse Events Reporting System. Both sources indicate pain at the injection site, nausea, and syncope as adverse effects of the vaccination.
    Allison L. Naleway, PhD, from the Center for Health Research, Kaiser Permanente Northwest, Portland, Oregon, and colleagues conducted a survey and collected electronic medical record information for 899 young women, aged 11 to 26 years, who were receiving their first injection from Kaiser Permanente Northwest during an 8-month period in 2008. Mail and telephone contact began within 1 week after the first of the series of vaccinations.
    The 50-item survey assessed knowledge about the virus, the vaccine, and adverse effects, and probed the relationships between participants and healthcare providers. "Such information could be used to design or focus interventions to improve HPV4 uptake and compliance with the three-dose HPV4 series and might identify opportunities for improved provider communication and education of vaccine recipients," the investigators write.
    Their results echoed earlier findings. About three quarters (696 [78%]) of the participants reported pain at the injection site, with up to 11% of them recalling the pain as severe to very severe. The percentage of respondents reporting pain and pain intensity was inversely proportional to age. A third of respondents reported pain worse than that from other vaccinations. One hundred fifty-five participants (17%) reported bruising, and 127 (14%) experienced swelling. These effects were reported more frequently among those younger than age 18.
    Eight women (1%) reported syncope after the first vaccination, and 133 (15%) reported presyncope. Receiving additional vaccines at the same time was associated with increased reporting of adverse events. Younger women were more likely to have received multiple vaccines.
    The researchers evaluated responses by age: 11 to 12 years (preteenagers), 13 to 17 years (adolescents), or 18 to 26 years (adults). Younger participants were less aware of the relationships among HPV, abnormal Pap test results, and genital warts. The value of age also emerged in assessment of personal risk. Fifteen percent of preteenagers, 8% of teenagers, and 4% of adults strongly agreed or agreed that they were too young to get cervical cancer. Older respondents were also more likely to recall seeing a vaccine advertisement (86% vs 55% for oldest and youngest groups, respectively; P < .0001).
    "Our study shows that age is an important factor influencing young women's experiences with the quadrivalent HPV vaccine," the researchers conclude. Limitations of the survey include the 27% response rate and the 9 cases in which parents refused to allow their daughters to participate.J Womens Health. Published online January 9, 2012. Abstract