The impact of the U.S. Preventive Services Task Force guidelines on cancer screening

The U.S. Preventive Services Task Force evaluated the medical literature, utilizing strict criteria to judge the merits of experimental trials designed to show benefit in screening for cancer. For individuals at normal risk, the task force was not able to make recommendations for or against screening for colorectal, prostate, skin, oral, or testicular cancers. Only one physical-examination cancer-screening procedure has ever been tested in a randomized trial. During the past 27 years, the National Cancer Institute (NCI) has funded six randomized screening trials. Thusfar, only one bas shown a decrease in mortality. Recognizing the limitations of such trials, the NCI published “Working Guidelines for Early Cancer Detection.” Designed for the practicing physician, these guidelines were based upon the best available evidence and on the judgment of representatives of medical professional organizations.     

Effectiveness of primary care-relevant treatments for obesity in adults: a systematic evidence review for the U.S. Preventive Services Task Force

Background: Overweight and obesity in adults are common and adversely affect health. Purpose: To summarize effectiveness and harms of primary care-relevant weight-loss interventions for overweight and obese adults. Data Sources: MEDLINE, Cochrane Central Register of Controlled Trials, and PsycINFO from January 2005 to September 2010; systematic reviews for identifying trials before 2005. Study Selection: Two investigators appraised 6498 abstracts and 648 articles. Clinical trials were included if control groups received minimal interventions. Articles were rated as good, fair, or poor by using design-specific criteria. Data Extraction: One investigator abstracted study characteristics and findings for good- and fair-quality studies; a second checked them. Data Synthesis: Behaviorally based treatment resulted in 3-kg (6.6-lb) greater weight loss in intervention than control participants after 12 to 18 months, with more treatment sessions associated with greater loss. Limited data suggest weight-loss maintenance for 1 year or more. Orlistat plus behavioral intervention resulted in 3-kg (6.6-lb) more weight loss than did placebo after 12 months. Metformin resulted in less weight loss. Data on effects of weight-loss treatment on long-term health outcomes (for example, death and cardiovascular disease) were insufficient. Weight-loss treatment reduced diabetes incidence in participants with prediabetes. Effects on intermediate outcomes (for example, lipids and blood pressure) were mixed and small. Data on serious medication harms were insufficient. Medications commonly caused withdrawals due to gastrointestinal symptoms. Limitations: Few studies reported health outcomes. Behaviorally based treatments were heterogeneous and specific elements were not well-described. Many studies could not be pooled because of insufficient reporting of variance data. Medication trials had high attrition, lacked postdiscontinuation data, and were inadequately powered for rare adverse effects. Conclusion: Behaviorally based treatments are safe and effective for weight loss and maintenance. Primary Funding Source: Agency for Healthcare Research and Quality.     

Risk factors and other epidemiologic considerations for cervical cancer screening: a narrative review for the U.S. Preventive Services Task Force

Despite the success of cervical cancer screening programs, questions remain about the appropriate time to begin and end screening. This review explores epidemiologic and contextual data on cervical cancer screening to inform decisions about when screening should begin and end. Cervical cancer is rare among women younger than 20 years. Screening for cervical cancer in this age group is complicated by lower rates of detection and higher rates of false-positive results than in older women. Methods used to diagnose and treat cervical intraepithelial neoplasia have important potential adverse effects. High-risk human papillomavirus infections and abnormalities on cytologic and histologic examination have relatively high rates of regression. Accordingly, cervical cancer screening in women younger than 20 years may be harmful. The incidence of, and mortality rates from, cervical cancer and the proportion of U.S. women aged 65 years or older who have had a Papanicolaou smear within 3 years have decreased since 2000. Available evidence supports discontinuation of cervical cancer screening among women aged 65 years or older who have had adequate screening and are not otherwise at high risk. Further reductions in the burden of cervical cancer in older women are probably best achieved by focusing on screening those who have not been adequately screened.