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Update From the Medical Journals: September 2011
September 28, 2011  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. Colonoscopy Before Age 50 May Be Best For Men Colon cancer is the third most common cancer in the United States. It's also the second leading cause of cancer deaths. U.S. doctors say men and women should get tested for colon cancer starting at age 50. (Some experts recommend that African Americans start screening at age 45, because colon cancer is somewhat more common in that group. Screening before 50 is also recommended for people with a family history of colon cancer.) But colon cancer usually appears at a later age for women than for men. So should both sexes start screening at the same age? A group of researchers in Austria tried to answer this question. They checked the colonoscopy examination results of 44,350 patients. One out of five had a polyp that needed removing. One out of every fifteen or sixteen patients had a polyp with "pre-cancer" changes or a cancer itself. But men were more likely to have these findings at younger ages. In fact, men ages 45 to 49 were as likely to have polyps as were women ages 55 to 59. The study was published in the Journal of the American Medical Association on September 28. The best screening test for colon cancer is a colonoscopy. If cancer is found, early treatment can cure about 9 out of 10 people. Removing polyps also helps to prevent cancer. For now, men and women with an average risk of colon cancer should get their first colonoscopy at age 50. Stay tuned, though. The authors of this study and several other experts think screening should start earlier for men. Back to top COPD Flares Less Frequent with Daily Antibiotic Chronic obstructive pulmonary disease (COPD) is usually caused by years of smoking. People with advanced COPD need to be hospitalized frequently due to flare-ups. These include coughing, wheezing and mucus production that cause shortness of breath and low oxygen. This lung disease is not caused by infection, but bacteria in the airways can add to symptoms. A study looked at whether a daily dose of an antibiotic could reduce the number of flare-ups in people with advanced COPD. The study included 1,142 people with COPD. People in the study were randomly divided into two groups. People in the treatment group took the antibiotic azithromycin. (This antibiotic is commonly known as Zithromax and is the antibiotic in the "Z-pak.") People in the other group received placebo (fake) pills. People who took the daily antibiotic were 27% less likely to have significant flare-ups than those taking the placebo pills. (The treated group had an average of 1.48 flare-ups per person in one year. The average number was 1.83 for those taking the placebo.) People who took azithromycin also reported better quality of life. Researchers did note hearing loss in 5% of the treated group, a possible side effect. The New England Journal of Medicine published the study August 25. Back to top More News in Brief - Discovery Explains Why Nerve Cells Lose Function in ALS. Scientists who have been studying ALS (amyotrophic lateral sclerosis), a devastating neurologic disease, have made a breakthrough. ALS is commonly known as Lou Gehrig's disease. In this disease, the brain and spinal cord gradually lose the ability to signal muscles. This causes muscles controlling movement, breathing, speech and swallowing to lose power. People with the disease gradually become paralyzed. Most people with ALS die of the disease within two to five years of diagnosis.
New research shows that ALS may result from the failure of a protein called ubiquilin2. This protein removes or repairs damaged proteins that are normal by-products of nerve activity. Without the "janitor" function of the ubiquilin2 protein, damaged proteins build up. This prevents nerves from sending signals. Ubiquilin2 does not work in patients who have ALS. This is true for inherited forms of ALS, as well as those without a family history. With this improved understanding of the disease, it is more likely that we may eventually have a drug that could treat ALS. The research was published August 22 in the journal Nature.
- Gene Gives Clue to Brain Chemistry in PTSD. After witnessing violence or a disaster, some people suffer from post-traumatic stress disorder (PTSD). People with this anxiety disorder relive the trauma through nightmares, flashbacks or recurring memories. PTSD can cause people to withdraw. But not every person who experiences trauma develops PTSD. Why do people respond to trauma so differently?
Psychiatric researchers were given a rare opportunity to try to answer this question. While they were studying college stress among 204 women at Northern Illinois University, a violent shooting occurred on campus in 2008. Five people were killed and at least 12 others were wounded. The researchers had already interviewed the women and knew their baseline levels of anxiety and stress. This allowed them to group the women according to their baseline stress levels, and compare the women within the same group. The researchers could then see if other factors, such as genetic differences, might identify the students who developed PTSD and those who did not.
They monitored the women for symptoms of PTSD. They also analyzed saliva samples to determine their gene patterns. A gene that regulates the brain hormone serotonin was of particular interest to the researchers. This gene has several forms — less common forms of the gene are called "variations" in the gene. They discovered that women who had variations in this gene were more likely to develop PTSD after a traumatic event: 52% of these women got PTSD symptoms compared with 42% of women who did not have the gene variations. This difference is not large (especially in a study that is small) but it does add weight to the suspicion that brain chemistry before exposure to trauma may contribute to a person's risk for later having symptoms of PTSD.
- HPV Vaccine Has Solid Safety Record. On September 13 the American Academy of Pediatrics (AAP) issued a statement online to correct any misinformation about the safety of the human papilloma virus vaccine (HPV vaccine). The vaccine protects against cervical cancer, which kills 4,000 women each year in the United States. Many Americans heard alarming statements about the vaccine during a recent political debate on television among Republican presidential candidates. Some candidates suggested that the vaccine had serious risks. One candidate even suggested that the vaccine can cause mental retardation.
According to the AAP statement, more than 35 million doses of the vaccine have been administered. The AAP points out that the vaccine has an excellent safety rate. There is no scientific evidence that links the vaccine to mental retardation. The AAP continues to strongly recommend the vaccine to girls at age 11 or 12. This is an age at which the vaccine has an excellent immune response and is able to protect against exposure to the virus before the onset of sexual activity. Back to top Mary Pickett, M.D. is an Associate professor at Oregon Health & Science University where she is a primary care doctor for adults. She supervises and educates residents in the field of Internal Medicine, for outpatient and hospital care. She is a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.
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