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Update From the Medical Journals: March 2008
March 31, 2008  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. Heart and Stroke Risks from Menopausal Hormone Therapy Go Away Immediately After Stopping Treatment, But Cancer Risk Lingers A study in the March 5 issue of the Journal of the American Medical Association (JAMA) followed 15,730 postmenopausal women who participated in the original Women's Health Initiative (WHI), and who stopped taking the combined estrogen plus progestin in 2002. Researchers wanted to know if risks associated with the treatment disappear after treatment stops. Estrogen therapy was thought to be protective until 2002, when the WHI found that the combined hormone treatment increased the risk of heart disease, stroke, pulmonary embolism (blood clot in the circulation to the lungs) and breast cancer. When these women stopped the hormones in 2002, they had been taking them for an average of 5.6 years. The researchers collected information about their health for an additional two to three years. (The average follow-up time was 2.4 years.) The extra risk for heart disease, stroke and pulmonary embolism did appear to go away immediately after a woman stopped the hormones. During the follow up time, there were no extra events in the group that had stopped hormones, compared with women who had never taken hormones in the first place. But breast cancer risk didn't revert back to lower levels immediately. Women who took the hormones previous to the WHI still had more breast cancer. During the first few years without hormones, there were about five breast cancers diagnosed in the group with hormone treatment "history" for every four breast cancers in the group that had never received HRT. This translated to a 27% higher risk in the group previously receiving hormones. The fact that cancer risk was higher among "quitters" compared with "never-users" is not surprising. It's similar, after all, to what we see in people who have quit smoking. It's likely that with a longer follow-up time, we will be able to see that this risk will diminish over time. Back to top Seven Acceptable Options for Colon Cancer Screening The American Cancer Society has expanded the list of tests it considers appropriate screening methods for colon cancer. The society issued the new guidelines online on March 5 in collaboration with the U.S. Multi-Society Task Force on Colorectal Cancer and the American College of Radiology. The guidelines will be published in the May-June 2008 issue of the American Cancer Society journal CA: A Cancer Journal for Clinicians. The new guidelines recognize seven different ways to check for colon cancer. The expert authors, however, emphasize that not all tests are equally effective. The most significant change is that "virtual colonoscopy" is one of the options. This test uses a combination of an enema (filling of the rectum with x-ray contrast dye) and a computed tomography (CT) scan to find polyps and cancer. Colon cancer screening is useful because it can find cancer before it has spread to lymph nodes. This means that treatment can be more successful. It can cure about 9 out of 10 people. If colon cancer is allowed to progress to a more advanced stage, it's usually not possible to cure it. Colon cancer is the second leading cause of cancer death in the United States. Colon cancer screening is also useful because it can prevent cancer. Some of the screening tests can find polyps. The surface of a polyp is often where a colon cancer begins. Removing the polyps helps to prevent colon cancer. The screening guidelines point out that the best screening tests for colon cancer are those that are likely to find both polyps and cancer. This includes: - Colonoscopy every 10 years – The entire colon is examined with a camera that is at the end of a flexible cord-shaped "scope."
- Flexible sigmoidoscopy every 5 years – The lower one-third of the colon is examined with a camera, which is at the end of a flexible cord-shaped "scope." This test differs from a colonoscopy because it is less expensive and it does not require sedation. If polyps are found, a colonoscopy is needed to remove them.
- Double-contrast barium enema (an X-ray test with an enema) every 5 years – The rectum is filled with X-ray contrast dye through a tube. Then, X-rays are done. If polyps are found, a colonoscopy is needed to remove them.
- CT colonography (virtual colonoscopy) every 5
years – The rectum is filled with X-ray contrast dye through a tube. Then, a CT scan is done. If polyps are found, a colonoscopy is needed to remove them. The remaining three tests are done on your stool. They help find early cancers, but they do not find polyps. They can't prevent cancer, but they can allow early treatment. - Fecal occult blood testing (FOBT) every year – This test is also known as "guaiac" test. Three stool samples are tested for "heme," which is present in fresh blood or digested blood. It detects blood from the esophagus, stomach, small intestines and colon. If the test is positive, a colonoscopy is needed to find the bleeding source and determine if it is cancer.
- Fecal immunochemical test (FIT) every year – Three stool samples are tested for "human hemoglobin," which is present in fresh blood. A positive test indicates bleeding from the colon; if you are bleeding from the stomach or esophagus, the test is usually negative. If the test is positive, a colonoscopy is needed to find the bleeding source in case it is a cancer. This test does not lead to a colonoscopy as often as the "guaiac" test, because it does not detect blood from irritation in the stomach or esophagus.
- Stool DNA test – It's unclear how often this is needed. An entire bowel movement must be packed in ice and undergo genetic testing. There are certain genes that can be found in cell fragments within the stool, if a cancer is present. This test is new and not as reliable as some of the other detection methods.
With more options to choose from, hopefully more people will get screened. Colon cancer screening is one of the most sensible ways you can protect your health. Back to top More News in Brief - One Out of Four Teenage Girls Has a Sexually Transmitted Infection. The Centers for Disease Control and Prevention (CDC) estimates that one out of every four girls in the U.S. between the ages of 14 and 19 had at least one sexually transmitted infection (STI) based on a sample of 838 girls who were tested for STIs in 2003 and 2004. The findings were presented March 11 at the 2008 National STD Prevention Conference. (They were also described in an online press release from the CDC.) Diseases tested for included human papillomavirus (HPV, the cause of cervical cancer), chlamydia, herpes simplex virus and trichomoniasis. Forty percent of the teenage girls reported that they were sexually active when they were surveyed. Among those who were sexually active, 48% of black teen girls and 20% of white teen girls had at least one STI. The girls who underwent testing were participating in the federally sponsored National Health and Nutrition Examination Survey, and are considered to be a representative sample of teenage girls in the U.S. Experts estimate that similar infection rates occur today. Increasing rates of vaccination against human papillomavirus and increasing education about safe sex practices are two ways that new infections can be reduced.
- Most Americans Don't Know the Warning Signs of a Heart Attack and Would Fail To React Quickly in an Emergency. According to a press release issued by the CDC on February 21, surprisingly few Americans know the five major signs of a heart attack. For example, only 34% to 59% of surveyed adults (depending upon the state they lived in) identified jaw or back pain as signs of a possible heart attack. Only about a quarter (27%) of adults who knew all five major signs of a heart attack were confident they should call 9-1-1 if a person they were with appeared to be having a heart attack. Based on the survey, Americans would also fail to recognize a stroke and might not know to call 9-1-1 for stroke symptoms. The data come from a 2005 survey of adults in 14 states. The five major symptoms of heart attack are chest pain or discomfort, pain or discomfort in the jaw, neck or back, feeling weak, lightheaded, or faint, pain or discomfort in the arms or shoulder and shortness of breath. A stroke can cause weakness or paralysis on one side of the body, sudden numbness, a loss of vision, difficulty walking, confusion and slurred speech or difficulty speaking.
- Survival Rates Improving Among People With Non-Hodgkin Lymphoma. A report in the March 10 issue of the Archives of Internal Medicine indicates that the ten-year relative survival rate for people diagnosed with non-Hodgkin lymphoma increased from 39% to 56% between 1990 and 2004. The researchers credit improved treatments for the disease and fewer HIV-related non-Hodgkin cases. Lymphomas are common among individuals with HIV infection but antiretroviral therapies have reduced lymphomas in those individuals.
Back to top Mary Pickett, M.D. is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Ore.
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