Annals of Internal Medicine is published by the American College of Physicians on the first and third Tuesday of every month. These highlights are not intended to substitute for articles as sources of information. For a copy of an article, call 1-800-523-1546, ext. 2656, or 215-351-2656, or visit www.annals.org. Past highlights are accessible as well.
The CDC estimates that 19 million new sexually transmitted infections (STIs) occur each year, almost half of which occur among persons 15 to 24 years of age. In an effort to decrease the spread of STIs, the U.S. Preventive Services Task Force (USPSTF) recommends high-intensity behavioral counseling for all sexually active individuals at increased risk for STIs. People at high risk include all sexually active adolescents, adults with a history of STIs within the past year, and adults with multiple sexual partners. Good-quality evidence suggests that multiple behavioral counseling sessions conducted in STI clinics and primary care settings effectively reduce STI incidence at both six months and one year after counseling. Additional trial evidence is needed to determine the effectiveness of both lower-intensity behavioral counseling interventions and counseling in lower-risk patient populations.
The newest stool DNA test is twice as effective at detecting colon cancer and polyps than either the fecal occult blood test or an older version of the DNA test. In a multicenter study of 3,764 healthy adults with an average risk for colon cancer, patients collected samples of stool at home and sent them to a laboratory that tested for hidden blood. Another laboratory tested the stool using two different types of DNA tests to see whether it contained DNA abnormalities associated with polyps or cancer. Researchers concluded that the best test for blood in the stool detected 21 percent of the cancer cases and the most worrisome types of polyps. The older of the two stool DNA tests (SDT-1) detected 20 percent of them. The newer stool DNA test (SDT-2) detected 40 percent of the cases of cancer and the most worrisome types of polyps. Researchers theorize that more user-friendly and widely distributable screening tools could improve screening effectiveness, acceptability, and access.
The USPSTF has updated its 2002 recommendations on colorectal cancer screening, taking into consideration the positive impact of screening on life expectancy. In an update of its 2002 guidelines, the USPSTF recommends screening for colorectal cancer annually with a sensitive fecal occult blood test (FOBT); every 10 years with a colonoscopy; or every five years with a flexible sigmoidoscopy and a mid-interval sensitive FOBT. Screening should begin at age 50 and continue until age 75. More evidence is needed to assess the benefits and harms of newer tests such as computed tomographic colonagraphy (CTC) and fecal DNA testing. The USPSTF recommends against routine screening for colorectal cancer in adults 76-85 years old. However, physicians should make screening decisions based on an assessment of the individual patient's risk factors and personal history. After 85 years of age, risks of screening may outweigh the benefits and, therefore, is not recommended.
A person's blood normally contains a certain amount of insulin-like growth factor, or IGF-I, a peptide that influences growth and other biological functions. However, at elevated levels, IGF-I is associated with a moderate increase in prostate cancer risk. Researchers reanalyzed data from 12 studies to determine the link between IGF-I and its associated binding proteins (IGFBPs) with risk of prostate cancer. Looking at 3,700 men with prostate cancer and 5,200 control participants, researchers noted that the greater the IGF-I concentration in the blood, the greater the risk for prostate cancer. Researchers conclude that this is an important study because IGF-I levels can by modified through diet and lifestyle changes. However, whether modifying levels would reduce prostate cancer risk is not known.