The Breast Self-Examination Controversy: What Providers and Patients Should Know

Article Outline

• Abstract
• Purpose
• Methods
• Literature Review
• Risk Factors for Breast Cancer
• Screening Methods for Breast Cancer
  • Mammography
  • Ultrasonography
  • MRI
  • Clinical Breast Examination
  • BSE
• References
• Copyright

Abstract 

Breast cancer is the second leading cause of cancer-related deaths in women. The efficacy of breast self-examination in decreasing cancer mortality is being questioned because of some recent evidence. This finding has led to various and controversial recommendations by key health organizations. This article explores this controversy and provides resources that nurse practitioners can use for discussions with patients and to help patients make informed decisions about the role of breast self-examination in their health care.

Keywords:  breast cancer screening , breast self-examination , efficacy of breast self-examination , recommendation for breast self-examination

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Breast cancer is a concern for many women in America. It is the second leading cause of cancer-related deaths in women, second only to lung cancer (Table 1).¹ Genetics, obstetric and gynecologic history, and environmental factors are probable contributors to the development and progression of breast cancer. Early detection, aided by screening, greatly decreases the mortality associated with this cancer² and allows for more treatment choices if breast cancer is found.

Table 1. Risk Factors Associated with Breast Cancer

Over the years, a variety of methods including mammography, breast ultrasound, magnetic resonance imaging (MRI), clinical breast examinations by a health professional, and breast self-examinations (BSE) have been used to screen for breast cancer. However, none of these screening tests is 100% sensitive in detecting breast cancer. Therefore, it is often recommended that a combination of these techniques be used in the screening process. Opinions vary as to which combinations of screening techniques are the most effective for identifying breast cancer.

The BSE is the only procedure that medical clinicians teach their patients (who are often nonmedically trained individuals) to perform. Recently, the effectiveness of BSE in detecting breast cancer has been questioned; however, most providers cannot even entertain the idea that BSE may be unnecessary.

In the past 20 years, there has been a great deal of controversy about the necessity of teaching and performing BSE.³ The literature identifies both positive and negative outcomes of BSE, which poses a dilemma in creating clinical guidelines. Both novice and expert healthcare professionals, such as nurse practitioners, should base their practice on the best clinical evidence. The lack of a consensus regarding a standard recommendation for BSE is problematic and confusing, especially for patients (Table 2).

Table 2. Recommendations on the Use of BSE

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Purpose 

Since recommendations from professional organizations and medical associations vary, the purpose of this paper was to develop clinical resources for healthcare professionals and patients regarding BSE. These clinical resources can help guide discussions about the role of breast self-examination in the breast cancer screening process. Resources include a reference guide (Table 3), talking points (Fig. 1), “red flags” (Fig. 2), and a website with instructions for performing BSE (American Cancer Society's website, A Guide to Performing a Self Breast Examination, at http://www.cancer.org/docroot/CRI/content/CRI_2_6x_How_to_perform_a_breast_self_exam_5.asp?sitearea=⁴¹). The reference guide includes website addresses of various organizations that present positions on BSE. Talking points were developed that summarize the benefits and risks of performing BSE as identified in the literature, enabling clinicians and patients to have information readily available to aid them in making informed decisions. The red flags (Fig. 2) include abnormal findings from the BSE that may cause concern. With these resources, healthcare professionals and patients will be better able to make educated decisions about the use of BSE.

Table 3. Reference Guide

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• Figure 1. 

  Talking points for breast self-examination.

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• Figure 2. 

  Red flags for breast self-examination.

(Sources: American Cancer Society²⁵ and the Centers for Disease Control and Prevention.⁴⁰)

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Methods 

A thorough review of the literature was conducted to compare various organizations' positions and to examine current research findings on the use of BSE. Using PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and other search engines, scholarly works and key organizations that addressed recommendations for BSE and potential benefits and harms of performing BSE were identified. Only papers published in the past 10 years were considered when we searched for relevant reports. Key search words included “self breast examination,” “breast self-examination,” “screening methods for breast cancer,” breast cancer screening,” and “recommendation for breast self-exam,” and databases included those of American College of Obstetrics and Gynecology (ACOG), United States Preventive Services Task Force (USPSTF), American Medical Association (AMA), American Cancer Society (ACS), American College of Family Practitioners (ACOFP), Canadian Taskforce for Preventive Healthcare, Susan G. Komen for the Cure Foundation, National Comprehensive Cancer Network, and American College of Radiology.

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Literature Review 

Breast cancer is the second leading cause of cancer-related deaths of women in the United States, second only to lung cancer according to the Centers for Disease Control and Prevention (CDC).¹ This type of cancer can also occur in men, although the occurrence is rare.⁴ In 2008, the National Cancer Institute (NCI) estimated that 182,460 females would be diagnosed with breast cancer in the United States that year and that 40,480 women would die due to breast cancer.⁵ It is estimated that 1 of every 8 women will develop breast cancer at some point during her life.⁵ Given the high incidence rate of breast cancer, identifying individual risk factors may be beneficial for early detection and treatment.

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Risk Factors for Breast Cancer 

Genetics, family history, obstetric and gynecologic history, and demographic and environmental factors influence the risks of developing breast cancer (Table 1). Nevertheless, the two most important risk factors for breast cancer are simply being female and aging. Research shows that gene mutations such as BRCA1 and BRCA2 are associated with a high risk of developing breast cancer.⁶ Lifetime breast cancer risk in a woman carrying BRCA1 or BRCA2 is 40 to 65%.⁷ The prevalence of these gene mutations in the general population is estimated to be 1 in 500.⁴ Of all breast cancer cases diagnosed in the United States, only 5 to 10% can be attributed to BRCA mutations.⁴ If an individual carries either of these genes, there is a 50% chance that her offspring will inherit these genes.⁷

Family history of breast cancer in a first-degree relative (mother, sister, or daughter) increases the likelihood that a woman will develop breast cancer.⁶ These women have twice the risk of developing breast cancer compared to a woman with no family history of breast cancer.⁸, ⁹ The degree to which breast cancer risk increases varies depending upon the number of first-degree relatives with breast cancer.⁴ Studies show that the risk is three to four times greater in women with more than one first-degree relative with a history of breast cancer.⁸, ⁹

A thorough obstetric and gynecologic history can help determine an individual's risk of breast cancer. According to Paley⁶, females who start menarche between the ages of 11 and 14 years carry an increased risk of breast cancer of up to 30% compared to those whose onset of menses occurs at 16 years of age. Findings in the obstetric history, including nulliparity, low parity, and increased age at first parity (age >30) are also identified as risk factors.⁶, ¹⁰ Breast cancer risk is doubled in women who have not given birth to children or who did not have their first child before age 30.⁶ Other factors associated with breast cancer are breastfeeding for less than 6 months, natural menopause, and the use of hormone replacement therapy.¹¹ A woman's age at menopause can also affect breast cancer risks. Women who experience menopause after the age of 55 have a 50% higher risk of being diagnosed with breast cancer than women who are menopausal between the ages of 45 and 55.⁶ Both the age at menarche and the age at menopause influence breast cancer risk due to the increased time that the body is exposed to estrogen.¹¹ Additionally, hormone replacement therapy exposes the body to increased amounts of estrogen, although the evidence regarding the relationship between hormone replacement therapy and breast cancer is mixed.

Demographic factors such as race, age, and obesity seem to influence breast cancer risks. Non-Hispanic white women have an increased incidence of breast cancer, but African-American, Hispanic, Native American, and Asian women have increased mortality from breast cancer.¹⁰ The variations in incidence of breast cancer and mortality from breast cancer among different populations are explained more by factors like education, income level, health insurance coverage, and diet than by genetic differences.¹⁰

As with many types of cancer, the risk of developing breast cancer increases with advanced age because cells have naturally undergone more divisions and can replicate in an uncontrolled fashion, leading to dysplasia of breast cells. The risk of breast cancer also increases in direct proportion to the degree of obesity. Two possible explanations for this increased cancer risk include increased levels of sex hormones such as estradiol in the blood and increased insulin or insulin-like growth factors.¹² Excess adipose tissue in those who are obese contains aromatase, which causes formation of estradiol outside of the glands.¹³ Increased levels of estradiol promote tumor growth and increase the rate at which a tumor grows.¹²

Last, environmental factors such as radiation exposure and increased alcohol consumption increase risks of breast cancer. Radiation treatments to the chest and upper body may increase breast cancer risks.⁴ An intake of one alcoholic drink or less per day can increase risk of breast cancer by as much as 10% in the general population.⁴ These risk factors help to identify high-risk populations, but it is necessary to screen all women, regardless of their risk factors.¹⁴

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Screening Methods for Breast Cancer 

A variety of screening methods are used to detect breast abnormalities and potential malignancies (e.g., mammography, ultrasonography, MRI, clinical breast examination, and BSE). However, the sensitivity and specificity of each test can vary. The sensitivity of a screening technique describes the rate at which the test can identify the presence of a disease. In other words, it predicts the probability of obtaining a positive test in those patients who actually have the disease. Problems with sensitivity produce false-negative results, leading to a missed diagnosis. The specificity of a test identifies the rate at which the absence of a disease can be detected or the probability of a negative result in patients who really do not have the disease. Problems with specificity produce false-positive results, leading to unnecessary workups.

Mammography 

The USPSTF¹⁵ and NCI¹⁶, ¹⁷ encourage the use of mammography as a screening tool for breast cancer every 1 to 2 years starting at age 40. The Susan G. Komen for the Cure Foundation¹⁸ (a leader in the fight against breast cancer) and ACS¹⁹ recommend mammography yearly starting at age 40. Mammography sensitivity ranges from 56 to 95% depending on the quality of the test performed and the age of the person being screened.¹⁵ Women younger than 40 tend to have denser breast tissue, which makes detecting tumors with mammography more difficult.²⁰ While mammograms have a relatively high sensitivity, the specificity of the examination may be inadequate, causing increased use of ultrasonography and biopsies.¹⁴

Ultrasonography 

Ultrasonography is not a first-line screening technique for breast cancer. It has a low detection rate for microcalcifications, which can be associated with breast cancer. Ultrasonography can be used to differentiate between fluid-filled cysts and solid tumors and can help with visualization for fine-needle aspiration procedures of the breast that can aid in diagnosis. It is often used in conjunction with mammography when lumps are detected that are difficult to evaluate with mammography alone.²¹ Several studies support the use of ultrasonography for breast cancer screening as an adjunct to mammography for high-risk women or women with dense breasts.⁴² One study showed that sensitivity was approximately 83.3% and specificity was 65.5% for breast ultrasonography.²²

MRI 

MRI is similar to ultrasonography in that it is not currently a first-line screening technique for breast cancer. MRI is used as an adjunct to mammography primarily in women who are at high risk for breast cancer. It can also be used to help with diagnosing lumps that remain after breast surgery or radiation therapy.²³ MRI is also used to examine breast masses that were detected with manual palpation but were not located with mammography or ultrasonography.²³ Studies are ongoing regarding MRI as a screening tool for breast cancer, but current evidence does not support the routine use of breast MRI as a screening procedure in average-risk women. ⁴³ One study found that MRI had a sensitivity of 79.5% and a specificity of 89.8%.²⁴ The NCI stated that false-positive results were not uncommon with MRI.²³ More studies supporting its cost benefits, effectiveness, and efficiency are needed before MRI is considered a routine screening method for breast cancer.

Clinical Breast Examination 

Recommendations for clinical breast examination (CBE) vary depending on the organization (Table 2). The ACS²⁵, ²⁶ and Susan G. Komen for the Cure Foundation²⁷ recommend CBE be performed at least every 3 years starting between ages 20 and 39 and annually starting at age 40. The ACOG¹⁴, ACR²⁸, and AMA²⁹ recommend starting CBE at age 40 and annually thereafter. The USPSTF states there is a lack of evidence to support CBE.¹⁵ The American Academy of Family Physicians (AAFP) tends to follow the recommendations of the USPSTF, indicating that there is insufficient evidence to support CBE.³⁰ The sensitivity for CBE ranges from 40 to 70%, and specificity ranges from 86 to 99%.¹⁵

BSE 

The sensitivity and specificity values of the BSE are difficult to determine.¹⁵ However, there are a number of advantages to performing a BSE, such as allowing women to gain a sense of control over their health and to become comfortable with their own breasts. Additionally, it is a simple, noninvasive procedure that can be performed by nonmedically trained individuals.³¹ According to the National Breast Cancer Foundation³², up to 70% of breast cancers are found by women performing their own BSE. The ACOG¹⁴ recommends the use of BSE as a tool for breast cancer screening, stating that palpable lesions can be detected through BSE (Table 2). The ACS also states that BSE can also help women recognize normal versus abnormal breast tissue.³

Although there are organizations that still recommend the practice of BSE, the use of this technique has come under scrutiny since newer screening technologies have been developed. Disadvantages of BSE include increased number of healthcare visits and twice the number of benign biopsy results, leading to increased healthcare costs.¹⁵, ³³ Another disadvantage is that increased biopsies lead to a higher risk of breast cancer. ⁶ According to the ACS³⁴, 4 of every 5 breast biopsy specimens are benign. With BSE, women detect changes in their breasts more often and are more likely to seek professional help and more definitive testing to rule out cancer, which increases healthcare costs.¹⁵ Additionally, when women discover abnormalities in their breasts, their feelings of anxiety and depression are likely to increase concerning what could possibly be a benign condition.¹⁵ This disease-specific anxiety could increase adherence to BSE in women; however, it could also lead to high levels of anxiety that require counseling or treatment.³⁵

Researchers have examined the efficacy of BSE in reducing breast cancer mortality. A study of 266,064 women in China, who were randomized to either receive instructions or not receive instructions in BSE, examined whether this instruction had any effect on the mortality of breast cancer. Thomas and colleagues³⁶ concluded “intensive instruction in BSE did not reduce mortality from breast cancer…Programs to encourage BSE in the absence of mammography would be unlikely to reduce mortality from breast cancer. Women who choose to practice BSE should be informed that its efficacy is unproven and that it may increase their chances of having a benign breast biopsy.”

The Canadian Taskforce on Preventive Health Care no longer recommends the use of BSE for breast cancer screening due to a lack of evidence supporting its benefits (i.e., detecting breast cancer at an earlier stage) and strong evidence of harm, such as unnecessary biopsies.³⁷ The ACS does not currently recommend performing BSE, as it did in the past (Table 2). Instead, ACS recommends that women of all ages should be told about benefits and harms associated with BSE. Possible benefits of BSE, according to ACS¹⁹, are increased awareness of breast changes leading to rapid evaluation and response to these changes. Possible harm is false-positive results.³⁸

The National Comprehensive Cancer Network (NCCN) recommends that women should be familiar with their breasts and promptly report any change to their healthcare provider. NCCN uses the term “breast awareness” to describe a woman's familiarity with her breasts and suggests that periodic consistent BSE may facilitate this breast awareness. Furthermore, they point out that this does not need to be done in any specific formalized education program and base this on the results of the Shanghai study.⁴³

Other organizations take a neutral stance on the use of BSE. For example, the USPSTF states “that the evidence is insufficient to recommend for or against teaching or performing routine breast self-examination.”¹⁵ As shown in Table 2, there is no consensus among organizations related to BSE. This poses a problem for healthcare professionals such as nurse practitioners who attempt to follow evidence-based guidelines in their practices. Lack of consensus also creates confusion for patients as they hear various recommendations from clinicians and the media.

Clinical resources can be helpful when there is conflicting information regarding a screening tool. Therefore, we developed several resources based on the review of literature regarding BSE. A reference guide (Table 3) was developed indicating various organizations' websites and their positions on BSE so that patients and clinicians can review them. Talking points (Fig. 1) were also developed that summarize the benefits and risks of performing BSE as well as risk factors associated with breast cancer based on current evidence. Thus, healthcare professionals and their patients will have information readily available to aid them in making informed decisions about whether or not BSE is a good option for them. The “red flags” guide (Fig. 2) includes information about abnormal findings that may be of concern on a BSE. Finally, the URL for the American Cancer Society's instructional guide for performing a BSE⁴¹ is included in the resources.

In summary, good clinical decision making involves consideration of best clinical evidence, the patient's clinical and emotional state, the clinical setting, and other circumstance specific to the patient's conditions. Resources presented here are intended to guide discussions on the use of BSE with patients. This will enable healthcare professionals and patients to review current guidelines, risks and benefits, and information on how to perform the BSE, if the woman chooses to do so. The ultimate goal is to empower women with the information they need to make educated decisions about their health.

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References 

1. Centers for Disease Control and Prevention  . Breast cancer statistics . Available at: http://www.cdc.gov/cancer/breast/statistics/ Accessed July 2, 2009
   • View In Article
2. Green BB , Taplin SH . Breast cancer screening controversies . J Am Board Fam Pract . 2003;16(3):233–241
   • View In Article
   • MEDLINE
3. Smith RA , Saslow D , Sawyer KA , et al.   American Cancer Society guidelines for breast cancer screening: update 2003 . CA Cancer J Clin . 2003;53(3):141–169
   • View In Article
   • MEDLINE
   • CrossRef
4. National Cancer Institute  . Genetics of breast and ovarian cancer . Available at: http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/HealthProfessional/page2#Section_344 Accessed September 16, 2008
   • View In Article
5. National Cancer Institute  . Surveillance epidemiology and end results fact sheets cancer: breast . Available at: http://seer.cancer.gov/statfacts/html/breast.html Accessed July 3, 2009
   • View In Article
6. Paley PJ . Screening for the major malignancies affecting women: current guidelines . Am J Obstet Gynecol . 2001;184(5):1021–1030
   • View In Article
   • Abstract
   • Full Text
   • CrossRef
7. Staton AD , Kurian AW , Cobb K , Mills MA , Ford JM . Cancer risk reduction and reproductive concerns in female BRCA1/2 mutation carriers . Fam Cancer . 2008;7(2):179–186
   • View In Article
   • CrossRef
8. Collaborative Group on Hormonal Factors in Breast Cancer . Familial breast cancer: collaborative reanalysis of individual data from 52 epidemiological studies including 58,209 women with breast cancer and 101,986 women without the disease . Lancet . 2001;358(9291):1389–1399
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (129 KB)
   • CrossRef
9. Pharoah PD , Day NE , Duffy S , Easton DF , Ponder BA . Family history and the risk of breast cancer: a systematic review and meta-analysis . Int J Cancer . 1997;71(5):800–809
   • View In Article
   • MEDLINE
   • CrossRef
10. Fejerman L , Ziv E . Population differences in breast cancer severity . Pharmacogenomics . 2008;9(3):323–333
    • View In Article
    • CrossRef
11. Phipps AI , Malone KE , Porter PL , Daling JR , Li CI . Reproductive and hormonal risk factors for postmenopausal luminal, HER-2-overexpressing, and triple-negative breast cancer . Cancer . 2008;113(7):1521–1526
    • View In Article
    • CrossRef
12. Kerlikowske K , Walker R , Miglioretti DL , Desai A , Ballard-Barbash R , Buist DS . Obesity, mammography use and accuracy, and advanced breast cancer risk . J Natl Cancer Inst . 2008;100(23):1724–1733
    • View In Article
    • CrossRef
13. Bulun SE , Zeitoun K , Sasano H , Simpson ER . Aromatase in aging women . Semin Reprod Endocrinol . 1999;17(4):349–358
    • View In Article
    • MEDLINE
14. National Guideline Clearinghouse  . Breast cancer screening . Available at: http://www.guideline.gov/summary/summary.aspx?doc_id=3990&nbr=003129&string=Breast+AND+Cancer+AND+Screening Accessed July 10, 2008
    • View In Article
15. Agency for Healthcare Research and Quality  . U.S. Preventative Services Task Force. Screening for breast cancer . Available at: http://www.ahrq.gov/clinic/uspstf/uspsbrca.htm Accessed July 10, 2008
    • View In Article
16. National Cancer Institute  . Screening mammograms: questions and answers . Available at: http://www.nci.nih.gov/cancertopics/factsheet/Detection/screening-mammograms Accessed December 4, 2008
    • View In Article
17. National Cancer Institute  . Breast cancer screening summary of evidence [health professional version] . Available at: http://www.cancer.gov/cancertopics/pdq/screening/breast/HealthProfessional/page2 Accessed July 3, 2009
    • View In Article
18. Susan G . Komen for the Cure. General recommendations . Available at: http://ww5.komen.org/BreastCancer/GeneralRecommendations.html Accessed October 31, 2008
    • View In Article
19. American Cancer Society  . American Cancer Society guidelines for the early detection of cancer . Available at: http://www.cancer.org/docroot/PED/content/PED_2_3X_ACS_Cancer_Detection_Guidelines_36.asp Accessed November 1, 2008
    • View In Article
20. Crystal P , Strano SD , Shcharynski S , Koretz MJ . Using sonography to screen women with mammographically dense breasts . AJR Am J Roentgenol . 2003;181(1):177–182
    • View In Article
    • MEDLINE
21. National Cancer Institute  . Improving methods for breast cancer detection and diagnosis . Available at: http://www.cancer.gov/cancertopics/factsheet/Detection/breast-cancer Accessed September 16, 2008
    • View In Article
22. Sim L , Hendriks J , Fook-Chong S . Breast ultrasound in women with familial risk of breast cancer . Ann Acad Med Singapore . 2004;33(5):600–606
    • View In Article
    • MEDLINE
23. National Cancer Institute  . Breast cancer screening [patient version] . Available at: http://www.cancer.gov/cancertopics/pdq/screening/breast/Patient/page3 Accessed July 3, 2009
    • View In Article
24. Kriege M , Brekelmans CT , Boetes C , et al.   Efficacy of MRI and mammography for breast-cancer screening in women with a familial or genetic predisposition . N Engl J Med . 2004;351(5):427–437
    • View In Article
    • CrossRef
25. American Cancer Society  . Overview: how is breast cancer found? . Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_2_3X_How_is_breast_cancer_found_5.asp?sitearea Accessed July 2, 2009
    • View In Article
26. American Cancer Society  . Can breast cancer be found early? . Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_4_3X_Can_breast_cancer_be_found_early_5.asp Accessed December 4, 2008
    • View In Article
27. Susan G . Komen for the Cure. Clinical breast exam . Available at: http://ww5.komen.org/BreastCancer/ClinicalBreastExam.html Accessed December 4, 2008
    • View In Article
28. Feig SA , D'Orsi CJ , Hendrick RE , et al.   American College of Radiology guidelines for breast cancer screening . AJR Am J Roentgenol . 1998;171(1):29–33
    • View In Article
    • MEDLINE
29. American Medical Association  . American Medical Association Women Physicians Congress policy compendium . Available at: http://www.ama-assn.org/ama1/pub/upload/mm/19/wpccompendfinal.pdf October 2007; Accessed July 2, 2009
    • View In Article
30. American Academy of Family Physicians  . A-E: recommendations for clinical preventive services [breast cancer] . Available at: http://www.aafp.org/online/en/home/clinical/exam/a-e.html Accessed July 2, 2009
    • View In Article
31. Elmore JG , Armstrong K , Lehman CD , Fletcher SW . Screening for breast cancer . JAMA . 2005;293(10):1245–1256
    • View In Article
    • CrossRef
32. National Breast Cancer Foundation, Inc.  . Breast self-exam (BSE) . Available at: http://www.nationalbreastcancer.org/about-breast-cancer/breast-self-exam.aspx Accessed February 9, 2009
    • View In Article
33. Kosters JP , Gotzsche PC . Regular self-examination or clinical examination for early detection of breast cancer . Cochrane Database Syst Rev . 2003;(2): CD003373
    • View In Article
34. American Cancer Society  . For women facing a breast biopsy . Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_4_6x_For_Women_Facing_a_Breast_Biopsy.asp?sitearea5 Accessed July 2, 2009
    • View In Article
35. Brain K , Norman P , Gray J , Mansel R . Anxiety and adherence to breast self-examination in women with a family history of breast cancer . Psychosom Med . 1999;61(2):181–187
    • View In Article
    • MEDLINE
36. Thomas DB , Gao DL , Ray RM , et al.   Randomized trial of breast self-examination in Shanghai: final results . J Natl Cancer Inst . 2002;94(19):1445–1457
    • View In Article
    • MEDLINE
    • CrossRef
37. Baxter N . Preventive health care, 2001 update: should women be routinely taught breast self-examination to screen for breast cancer? . CMAJ . 2001;164(13):1837–1846
    • View In Article
    • MEDLINE
38. Smith RA , Cokkinides V , Eyre HJ . American Cancer Society guidelines for the early detection of cancer, 2006 . CA Cancer J Clin . 2006;56(1):11–25
    • View In Article
    • MEDLINE
    • CrossRef
39. Canadian Task Force on Preventive Health Care  . Canadian Task Force on preventive health care systematic reviews and recommendations: neoplasms-breast cancer . Available at: http://www.ctfphc.org/ Accessed July 2, 2009
    • View In Article
40. Centers for Disease Control and Prevention  . Understanding breast health . Available at: http://www.cdc.gov/cancer/breast/fact_breast_health.htm Accessed July 2, 2009
    • View In Article
41. American Cancer Society  . How to perform a breast self-exam . Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_6x_How_to_perform_a_breast_self_exam_5.asp?sitearea Accessed January 13, 2009
    • View In Article
42. Pisano ED , Gatsonis C , Hendrick E , et al.   Diagnostic performance of digital vs. film mammography for breast cancer . N Engl J Med . 2005;353:1773–1783
    • View In Article
    • CrossRef
43. National Comprehensive Cancer Network  . Breast cancer screening and diagnosis (practice guidelines in oncology) version I, 2010 . Available at www.nccn.org/professionals/physician : 1-49. Accessed November 4, 2009
    • View In Article