May 30, 2012Volume 7 - Issue 22  

DynaMed Weekly Update

For the week ending May 25, 2012

Last week 616 articles were evaluated via DynaMed's Systematic Literature Surveillance and 333 were added to DynaMed content.

Based on the editors' criteria of selecting "articles most likely to change clinical practice," one article of significant interest was selected for the DynaMed Weekly Update.

Feature Article

Flexible Sigmoidoscopy Reduces Colorectal Cancer Incidence and Mortality Compared to Usual Care


To screen patients at average risk for colorectal cancer, the United States Preventive Services Task Force (USPSTF) recommends 1 of 3 screening options: high-sensitivity fecal occult blood testing every year, flexible sigmoidoscopy every 5 years or colonoscopy every 10 years for patients aged 50-70 years (Ann Intern Med 2008 Nov 4;149(9):627).The American Cancer Society and American Gastroenterological Association recommendations include the same 3 options, but also include double-contrast barium enema every 5 years or computed tomographic (CT) colonography every 5 years as additional options (CA Cancer J Clin 2008 May-Jun;58(3):130). The optimal method of screening has yet to be determined. The efficacy of flexible sigmoidoscopy was evaluated in 154,900 patients as part of the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial.


Patients aged 55-74 years were recruited through mass mailings and randomized to screening with flexible sigmoidoscopy vs. usual care from 1993-2001. The sigmoidoscopy group was offered screening at baseline and again 5 years later (3 years later for patients recruited during the first 2 years of the trial). Patients with a positive screen (detection of polyp or mass) were referred for additional diagnostic consultation. In the sigmoidoscopy group, 83.5% had baseline screening and 54% had repeat screening. Colonoscopy was performed in 5.5% during their first 5 years in the trial (screening phase) and in 47.7% after the screening phase. Details of screening that the usual care group received were not given, but 46.5% had either flexible sigmoidoscopy or colonoscopy during the screening phase of the trial and 48% had routine colonoscopy after the screening phase.


Median follow-up was 11.9 years. Colorectal cancer occurred in 1.31% in the flexible sigmoidoscopy group vs. 1.66% in the usual care group (p < 0.001, NNT 286), and colorectal cancer mortality was significantly reduced with sigmoidoscopy (0.325% vs. 0.44%, p < 0.001, NNT 870) (level 1 [likely reliable] evidence). Incidence per 10,000 person-years was 5.6 vs. 7.9 for distal colorectal cancer (p < 0.95) and 6 vs. 7 for proximal colorectal cancer. There was no significant difference in death from other causes, excluding prostate, lung and ovarian cancers (11.8% vs. 12%) (N Engl J Med 2012 May 21 early online).


For more information, see the Colorectal cancer screening topic in DynaMed. 



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DynaMed Extra
New USPSTF Guideline Recommends Against PSA Screening for Prostate Cancer 

The United States Preventive Services Task Force (USPSTF) has released a new recommendation statement for prostate cancer screening with prostate-specific antigen (PSA)-based assays. USPSTF currently recommends against PSA testing as a screening tool for all men in the United States, regardless of age (USPSTF Grade D recommendation). The previous statement from 2008 had recommended against screening for men > 75 years old and had found insufficient evidence for younger men. The new recommendation does not cover the use of PSA tests after diagnosis or during treatment of prostate cancer (Ann Intern Med 2012 May 21 early online).


For more information, see the Prostate cancer screening topic in DynaMed.

New Topics added to DynaMed this Week
Lateral medullary syndrome
Call for Peer Reviewers

We are currently seeking reviewers for:

Familial adenomatous polyposis

Gastrointestinal stromal tumor


Learn more about the DynaMed Contribution Opportunities:

DynaMed Peer Review 

Editorial Policies for Reviewers 


About DynaMed Weekly Update

Prepared by the clinician members of the DynaMed Editorial Team, DynaMed Weekly Update is a compilation of one to five articles selected from DynaMed's Systematic Literature Surveillance as articles most likely to change clinical practice.

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CME Information


0.25 AMA PRA Category I Credit(s)™
Family Physicians: 0.25 Prescribed credits
Nurse Practitioners: 0.25 Contact hours
Release Date: May 30, 2012
Expiration Date: May 30, 2013
Estimated Completion Time:
15 minutes
There is no fee for this activity.

To Receive Credit 
In order to receive your certificate of participation, you should read the information about this activity, including the disclosure statements, review the entire activity, take the post-test, and complete the evaluation form. You may then follow the directions to print your certificate of participation. To begin, click the CME icon at the end of the article.

Program Overview

Learning Objectives

Upon successful completion of this educational program, the reader should be able to:
1. Discuss the significance of this article as it relates to your clinical practice.
2. Be able to apply this knowledge to your patient's diagnosis, treatment and management.
Faculty Information
Alan Ehrlich, MD - Assistant Clinical Professor in Family Medicine, University of Massachusetts Medical School, Worcester, Massachusetts, USA; Deputy Editor, DynaMed, Ipswich, Massachusetts, USA

Michael Fleming, MD, FAAFP - Assistant Clinical Professor of Family Medicine and Comprehensive Care, LSU Health Science Center School of Medicine, Shreveport, Louisiana, USA; Assistant Clinical Professor of Family Medicine, Department of Family and Community Medicine, Tulane University Medical School, New Orleans, Louisiana, USA; Chief Medical Officer, Amedisys, Inc. & Antidote Education Company

Dr. Ehrlich, Dr. Fleming, DynaMed Editorial Team members, and the staff of Antidote Education Company have disclosed that they have no relevant financial relationships or conflicts of interest with commercial interests related directly or indirectly to this educational activity.
No commercial support has been received for this activity.

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ACCME This activity has been planned and implemented in accordance with the Essential Areas and policies of the Accreditation Council for Continuing Medical Education through the joint sponsorship of Antidote Education Company and EBSCO Publishing. Antidote is accredited by the ACCME to provide continuing medical education for physicians.  Antidote Education Company designates this enduring activity for a maximum of 0.25 AMA PRA Category 1 Credits™. Physicians should only claim credit commensurate with the extent of their participation in the activity.

AAFP: This Enduring Material activity, DynaMed Weekly Update, has been reviewed and is acceptable for up to 13 Prescribed credits by the American Academy of Family Physicians. AAFP certification begins March 7, 2012. Term of approval is for one year from this date with the option of yearly renewal. Each Weekly Update is worth .25 Prescribed credits. Physicians should claim only the credit commensurate with the extent of their participation in the activity. 


AANP: This program is approved for 0.25 contact hour of continuing education by the American Academy of Nurse Practitioners.  

Program ID 1102072M.

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