Raloxifene Approved for Reducing Invasive Breast Cancer Risk

The osteoporosis drug raloxifene (Evista) has been approved for the prevention of invasive breast cancer in postmenopausal women with osteoporosis or postmenopausal women at high risk for invasive breast cancer, the FDA announced Friday.

The agency warned that raloxifene, a selective estrogen receptor modulator, should not be taken with cholestyramine or estrogens. Premenopausal women, especially if they are pregnant or considering pregnancy, also should not take this drug.

Raloxifene can cause serious side effects, including deep venous thrombosis, pulmonary embolism, and death due to stroke. Accordingly, the director of the FDA's Center for Drug Evaluation and Research cautioned that "the benefits and risks of taking [raloxifene] should be carefully evaluated for each individual woman."

Guidelines on MRI Detection of Breast Cancer

The American Cancer Society yesterday released new guidelines for breast cancer screening with MRI as an adjunct to mammography. The principal recommendations, based on literature published between 2002 and 2006, follow.


Annual MRI screening for:


-- those with BRCA mutations
-- first-degree relatives of BRCA carriers

-- those with 20% or greater lifetime risk, as defined by BRCAPRO and other family-history-dependent models

-- those having received chest irradiation between age 10 and 30

-- those with Li-Fraumeni syndrome, Cowden syndrome, and Bannayan-Riley-Ruvalcaba syndrome or their first-degree relatives



Insufficient evidence to recommend for or against MRI screening for:



-- those with a lifetime risk of 15-20%

-- those with lobular carcinoma in situ or atypical lobular hyperplasia

-- those with atypical ductal hyperplasia

-- those with heterogeneous or extreme breast density on mammography

-- those with a personal history of breast cancer, including ductal carcinoma in situ



Women with a less than 15% lifetime risk are recommended not to have MRI screening.

Guideline: Mammography optional in women 40-49

Clinical Question: Should screening mammography be used in women between the ages of 40 years and 49 years?

Bottom Line: In a break from other authorities, this evidence-based guideline from the American College of Physicians (ACP) makes no absolute recommendation for or against the screening of women between the ages of 40 years and 49 years. Instead, it recommends routine, periodic risk assessment, as well as discussions with individuals regarding the benefits and harms of screening mammography.(LOE = 1a)

Reference: Armstrong K, Moye E, Williams S, Berlin JA, Reynolds EE. Screening mammography in women 40 to 49 years of age: a systematic review for the American College of Physicians. Ann Intern Med 2007;146:516-526. [Free full-text Annals article online] [Medline® abstract]

Study Design: Practice guideline
Funding: Foundation
Setting: Various (guideline)

Synopsis

Here's an underappreciated fact: More women between the ages of 40 and 49 years die from heart disease (6800) than from breast cancer (5000) each year. To develop this guideline, the ACP researchers analyzed the latest meta-analyses on this topic and considered an additional study that was subsequently published. The main findings: There are 7% to 23% fewer deaths due to breast cancer over an average of 14 years with screening starting at age 40; an overall mortality reduction hasn't been shown; screening increases rates of mastectomy; rates of ductal carcinoma in situ diagnosis skyrocket 7-fold with increased screening, representing 25% of the diagnoses of "cancer" in this age group; and, 20% to 56% of women will have a false-positive diagnosis when tested yearly for 10 years. In addition to recommending more research, the authors made 3 recommendations:

(1) The decision of whether to order a screening mammography should be made on an individual basis, taking into account the benefits, harms, risk profile, and patient preferences.

(2) Clinicians should update a woman's risk profile every 1 to 2 years. Risk factors for all women include a family history of breast cancer, earlier menarche, later age at time of first birth, and a history of breast biopsy. In addition, women aged 40 to 49 years with certain risk factors are at higher risk than the average 50-year-old woman, including 2 first-degree relatives with breast cancer and 2 previous breast biopsies. The Gail Risk Model Calculator (available in InfoRetriever) can be used to determine an individual woman's risk.

(3) Clinicians should discuss the potential benefits and harm of screening mammography with their patients. The most recent meta-analysis found a reduction in breast cancer-related mortality by 15%, although the confidence interval was wide (as little as 1% risk reduction and as much as 27% risk reduction). A more recent randomized trial, which was not included in the meta-analysis, found no statistically significant reduction in risk of breast cancer mortality. Potential harms include false-positive results, which are as high as 20% to 56% over the course of 10 mammograms, as well as the anxiety associated with the false-positives. Other theoretical risks include discomfort with the procedure. The authors found no evidence of increased radiation-induced cancer or overdiagnosis due to screening.

Written by Cung Pham, MD

Copyright © 2007 by Wiley Subscription Services, Inc. All rights reserved. www.infopoems.com

Calcium and Vitamin D Intake and Risk for Breast Cancer

Higher calcium and vitamin D intake showed modest benefit in premenopausal women.

Animal experiments and observational human studies suggest that calcium and vitamin D may decrease risk for breast cancer. Researchers prospectively assessed this relation among 10,000 premenopausal and 20,000 postmenopausal women enrolled in the Women’s Health Study. Calcium and vitamin D intake was determined from self-reported questionnaires about food and vitamin supplement intake.

During a mean follow-up of 10 years, the overall incidence of invasive breast cancer was 2.6% among premenopausal women and 3.6% among postmenopausal women. The hazard ratio for developing invasive breast cancer was 0.61 for premenopausal women at the highest versus lowest quintiles of calcium intake and 0.65 for vitamin D intake. No relation was found between calcium and vitamin D intake and risk for invasive breast cancer among postmenopausal women.

Comment: In this large, prospective study, a higher intake of calcium and vitamin D was associated with a lower risk for invasive breast cancer among premenopausal but not postmenopausal women. Although the hazard ratios appear relatively large, the absolute risk reduction was modest. Limitations of this study include ascertainment of calcium and vitamin D intake only once at baseline and the possibility that unmeasured confounding variables explain the findings in this nonrandomized assessment of diet.

— Jamaluddin Moloo, MD, MPH

Published in Journal Watch General Medicine June 14, 2007

Citation(s):

Lin J et al. Intakes of calcium and vitamin D and breast cancer risk in women. Arch Intern Med 2007 May 28; 167:1050-9