This statement summarizes the inst...

This statement summarizes the instant U.S. Preventive Services Task Force (USPSTF) recommendations for the chemoprevention of breast cancer and the supporting scientific evidence. Explanations of the in every one's mouth ratings and of the vigor of overall evidence are given in Tables 1 and 2 respectively. The unbroken information on which this statement is based is available in the article "Chemoprevention of Breast Cancer: A Summary of the Evidence" (1) and in the summary of the evidence and Systematic Evidence Review2 forward this topic, available through the USPSTF Web site (www.preventiveservices.ahrq.gov) and the National Guideline Clearinghouse (www.guideline.gov). A summary of the evidence is also available in print from one side the Agency for Healthcare Research and Quality Publications Clearinghouse (telephone: 800-358-9295; e-mail: ahrqpubs@ahrq.gov).

Summary of Recommendations

* The USPSTF praises against the routine use of tamoxifen or raloxifene for the primary prevention of breast cancer in women at gentle or average risk for breast cancer (See "Clinical Considerations" for a discussion of risk). (D recommendation)

The USPSTF institute fair evidence that tamoxifen and raloxifene may obstruct some breast cancers in women at subdued or average risk, based forward extrapolation from studies of women at higher risk. The USPSTF conclud however, that the potential harms of chemoprevention may outweigh the potential benefits in women who are not at high risk for breast cancer.

* The USPSTF praises that clinicians discuss chemoprevention with women at high risk for breast cancer and at reasonable risk for adverse effects of chemoprevention. Clinicians should inform patients of the potential benefits and harms of chemoprevention. (B recommendation)

The USPSTF fix fair evidence that treatment with tamoxifen can significantly bring to the risk for invasive estrogen-receptor-positive breast cancer in women at high risk for breast cancer and that the likelihood of benefit increases as the risk for breast cancer increases. The USPSTF fix consistent but less abundant evidence for the benefit of raloxifene. The USPSTF construct good evidence that tamoxifen and raloxifene increase the risk for thromboembolic ends (for example, stroke, pulmonary embolism, and profound venous thrombosis) and symptomatic side consequences (for example, hot flashes) and that tamoxifen, yet not raloxifene, increases the risk for endometrial cancer. The USPSTF conclud that the balance of benefits and harms may be favorable for a certain high-risk women but will hang on breast cancer risk, risk for potential harms, and individual patient preferences

Clinical Considerations

* Clinicians should consider the pair the risk for breast cancer and the risk for adverse results when identifying women who may be candidates for chemoprevention.

Risk for breast cancer: Older age; a family history of breast cancer in a mother, sister, or daughter; and a history of atypical hyperplasia forward a breast biopsy are the strongest risk factors for breast cancer. Table 33 indicates by what means the estimated benefits of tamoxifen vary depending onward age and family history. Other factors that contribute to risk include race, early age at menarche, pregnancy history (nulliparity or older age at first birth), and number of breast biopsies. The risk for developing breast cancer within five years can be estimated using risk-factor information through completing the National Cancer Institute Breast Cancer Risk Tool (the Gail design available at www.cancer.gov/ bcrisktool/ or 800-4-CANCER [800-422-6237]) Clinicians can use this information to help patients considering tamoxifen therapy estimate the potential benefit. However, the validity, feasibility, and impact of using the Gail protoplast to identify appropriate candidates for chemoprevention has not been standarded in a primary care setting. The Gail archetype does not incorporate estradiol of the same heights or estrogen use, factors that one studies suggest may influence the effectiveness of tamoxifen.

Risk for adverse effects: Women are at lower risk for adverse events from chemoprevention if they are younger; have no predisposition to thromboembolic occurrences such as stroke, pulmonary embolism, or profound venous thrombosis; or do not have a uterus.

* In general, the balance of benefits and harms of chemoprevention is more favorable for women in their 40 who are at increased risk for breast cancer and have no predisposition to thromboembolic occurrences and women in their 50 who are at increased risk for breast cancer, have no predisposition to thromboembolic incidents and do not have a uterus. For example, a woman who is 45 years of age and has a mother, sister, or daughter with breast cancer would have approximately a 16 percent risk for developing breast cancer across five years. On average, treating of that kind women with tamoxifen for five years would impede about three times as many invasive cancers (eight by 1,000) as the number of serious thromboembolic complications caused (one attack and one to two pulmonary emboli by 1,000). Among women 55 years of age, benefits exce harms solitary for those who are not at risk for endometrial cancer, and the margin of benefit is small unles risk for breast cancer is substantially increased (for example, 4 percent through the whole extent of five years).