December 12, 2012
Volume 7 - Issue 50      

DynaMed Weekly Update

For the week ending December 07, 2012

Last week 667 articles were evaluated via DynaMed's Systematic Literature Surveillance and 307 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

Continuing Tamoxifen Beyond 5 Years May Reduce Recurrence and Mortality in Women with Estrogen Receptor-Positive Early Breast Cancer


In women with estrogen receptor (ER)-positive early breast cancer, adjuvant tamoxifen treatment for 5 years has been associated with reduced recurrence and breast cancer mortality for up to 15 years compared to either no tamoxifen treatment or treatment for 1-2 years (Lancet 2011 Aug 27;378(9793):771). Tamoxifen for 5 years is recommended for premenopausal women with early breast cancer (New Zealand Guidelines Group 2009 Aug). The newly-published Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) trial evaluated whether continuing tamoxifen for an additional 5 years would further improve outcomes in a group of 12,894 women. Previous smaller trials have not shown a benefit of such extended tamoxifen treatment.   


In the ATLAS trial, women with early breast cancer who had completed 5 years of tamoxifen treatment were randomized without blinding to continued tamoxifen (20 mg/day) for a total 10 years vs. immediate stopping of tamoxifen treatment. ER status was positive in 53% (6,846 women), negative in 10% and unknown in 37%. Women were excluded at clinician discretion for any contraindication to continued tamoxifen. In the 10-year treatment group, treatment could be stopped for emergent definite contraindications and it could be restarted in the 5-year treatment group for definite indication. At publication, 91% had completed 10 years follow-up and 77% had completed 15 years follow-up. The adherence rates in the 10-year treatment group were 84% at 7 years and < 60% at 10 years.


In the prespecified subgroup of ER-positive women, the rates of breast cancer recurrence were 18% with 10-year tamoxifen treatment vs. 20.8% with 5-year treatment (p = 0.002, NNT 36) (level 2 [mid-level] evidence). Tamoxifen for 10 years was associated with reductions in both breast cancer mortality (9.66% vs. 11.6%, p = 0.01, NNT 52) and all-cause mortality (18.6% vs. 21.1% (p = 0.01, NNT 40). The benefits of continued treatment for both recurrence and mortality were significant at ≥ 10 years follow-up, but not at 5-9 years follow-up. There were no significant differences in mortality in analysis of women with ER-negative status or unknown ER status.


The risks of other adverse outcomes occurring prior to recurrence were analyzed in all women regardless of ER status. Continued tamoxifen treatment was associated with increased risk of endometrial cancer (event rate ratio 1.74, 95% CI 1.3-2.34) and pulmonary embolism (event rate ratio 1.87, 95% CI 1.13-3.07), and decreased risk of ischemic heart disease (event rate ratio 0.76, 95% CI 0.6-0.95). There was no significant difference in the rates of endometrial cancer-related death (Lancet 2012 Dec 4 early online).


For more information, see the Endocrine therapy for breast cancer topic in DynaMed.

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Cerebellar ataxia 

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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: December 12, 2012
Expiration Date: December 12, 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; Senior 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: 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: 1210392O

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