Although approximately $20 billion is spent annually in the United States for breast cancer screening and treatment, misdiagnoses of breast malignancies and delayed treatment of breast cancer together are the second-leading cause of medical malpractice cases in the United States.1,2 Given that breast cancer has the second-highest death rate of all cancers in American women, it is vital to not only ensure that thorough and correct assessment of breast lesions occur, but also that unnecessary measures are avoided.3
Diagnostic breast imaging (predominantly mammogram and ultrasound, but MRI may be used as an adjunct study) is an important tool used to investigate an abnormal physical examination finding and help clarify the results from an inconclusive mammogram. It is imperative for primary care providers to be able to identify which patients would benefit from this evaluation to provide optimal healthcare.
Obtaining a comprehensive history
A comprehensive breast evaluation is required for both screening examinations and diagnostic assessments. For the primary care provider, the conundrum is to differentiate benign or hormonally related breast changes from suspicious or potential malignant changes. Eliciting an accurate history is imperative when assessing, diagnosing, and treating a patient, as well as referring a patient for further treatment.
Factors that affect a woman's risk of breast cancer include use of oral contraceptives or hormone replacement therapy (HRT); previous chest radiation; diethylstilbestrol (DES) exposure; alcohol use; body mass index; menstrual, pregnancy, and breastfeeding histories; personal history of breast conditions or breast cancer; breast density; and family history of breast cancer and genetic risk factors.4,5 Women who use oral contraceptives have a slightly greater risk of breast cancer than women who have not taken them.4 The use of combined HRTs, which include estrogen and progesterone, has been found to increase the risk of breast cancer in menopausal women.4 Women who have had radiation therapy to the chest for treatment of other types of cancer have a significantly increased risk of acquiring breast cancer. Those exposed to DES during pregnancy have a slightly increased risk of developing breast cancer.3,4 Alcohol use has been associated with the elevated risk of breast cancer as well as obesity, early menarche, and late menopause.4 Nulliparous women or women who had their first child after age 30 have an enhanced risk of breast cancer occurrence; however, some studies indicate that breastfeeding, especially for at least 1½ to 2 years, may decrease breast cancer risk.4
Personal history of breast disease may affect breast cancer risk. A woman's history of pathologically diagnosed benign breast disease without atypia such as complex fibroadenoma, sclerosing adenosis, papilloma, or radial scar increases the risk of breast cancer twofold.4 Lesions with atypia, including atypical ductal and atypical lobular hyperplasia, raise a woman's risk of developing breast cancer 4 to 5 times.4 Breast density is an important factor as dense breasts have more glandular tissue than fatty tissue, and breast cancers tend to develop within this dense tissue.3 Density can be evaluated by both physical examination and mammography.3
Hereditary factors also affect the possibility of breast cancer occurrence. Approximately 20% to 30% of women with breast cancer have a family member with breast cancer.4 Knowing whether a patient has any genetic mutations, especially BRCA1 and BRCA2 gene mutations, affects screening protocols and can guide referrals to specialists. Genetics counselors can provide appropriate counseling and screening protocols if a patient has or is suspected to have a genetic mutation. Patients with BRCA gene mutations should have a clinical breast examination every 6 months beginning at age 25 and magnetic resonance imaging (MRI) alternating with mammography every 6 months beginning at age 25.6
In patients presenting with a specific complaint, additional questions specific to the problem should be addressed. For breast masses, practitioners should note mass onset, duration, associated pain, redness, fever, or discharge.7,8 If nipple discharge is present, the spontaneity of the discharge along with color, site and location (unilateral or bilateral, one duct or multiple ducts), medical history (thyroid, pituitary, or hypothalamic disorders), current or recent pregnancy, current or recent breastfeeding, and medication use (psychiatric drugs, antihypertensive drugs, opiates, oral contraceptives/HRT) should be reviewed.8,9 The presence or absence of these particular endocrine disorders, as well as the use of certain prescribed medications, must be considered in the assessment of nipple discharge from nonmalignant causes.
A relationship between menstrual cycles (if not menopausal) and breast pain should be established. Description of the pain (diffuse or focal, unilateral or bilateral) and aggravating and relieving factors should be evaluated. History of trauma, past breast surgeries, pregnancy, and exogenous hormone and caffeine intake are also important considerations.8 Skin or nipple/areolar changes (thickening, lesions, rash, or discoloration) should be assessed in the context of onset, duration, associated factors such as trauma or piercings, and history of radiation therapy. Pertinent medical history that might predispose patients to skin changes of the breast such as diabetes, eczema, or hidradenitis suppurativa should be assessed to differentiate benign skin changes versus those of Paget disease.9
The clinician should also conduct a thorough examination of the breasts. Complete physical assessment is necessary to differentiate referrals for diagnostic mammographic evaluation versus screening mammography. According to the American College of Radiology (ACR), patients should be referred for a diagnostic mammogram for a mass, axillary lymphadenopathy, nipple discharge, changes in skin or nipple/areola, and focal pain or tenderness.10
Palpable breast or axillary masses or asymmetries on physical examination should be referred for further diagnostic evaluation.9,8 Masses most associated with malignancy include firm or fixed masses as well as those with indistinct borders.9 Smooth, mobile masses with defined borders are generally of benign origin.9 However, masses need further assessment to identify them positively as benign; patients 30 years and older need a diagnostic mammography, and patients younger than 30 years need an ultrasound.9
Nipple discharge is a common occurrence in women, and adequate assessment is essential for evaluation, diagnosis, and treatment. Nipple discharge can be divided into two categories: discharge concerning for the presence of a pathologic process versus benign or physiologic discharge. Pathologic nipple discharge should be referred for diagnostic imaging and is commonly characterized as unilateral, single duct, spontaneous, bloody, clear, or purulent.8 Physiologic nipple discharge is usually bilateral, multiduct, nonspontaneous (occurs with stimulation), and may be milky, brown, yellow, green, or black.9 If the provider is unable to illicit nipple discharge at the time of the visit, the patient should return at the time of next nipple discharge.11 The provider must see the discharge for complete evaluation.
Skin changes of the breast should be considered carefully. Women with new-onset inflammatory skin changes of the breast can be given a 10-day trial of antibiotics with a repeat clinical breast examination.11 If all signs and symptoms resolve, then the patient may resume routine clinical follow-up and screening. If any changes persist, referral for diagnostic imaging evaluation should take place.11 Nipple or areolar rashes or inversion should be referred for diagnostic imaging.10 It is important to differentiate between common hormonally related findings versus possibly malignant findings (see Physical examination of the breast). When pain is present, the physical examination of the breast in premenopausal women must be carefully considered in relation to the menstrual cycle. Pain that is cyclic, associated with menses, and accompanied by diffuse, bilateral nodularity and tenderness is usually physiologic and benign.8 If there is any uncertainty regarding the presence of nodularity, the patient can be reevaluated 1 to 2 weeks after menses to establish resolution of this finding or referred for diagnostic radiologic evaluation if these findings persist. Women who present with new-onset, focal, or persistent pain on physical examination should be referred for diagnostic radiologic evaluation.10 Women who present with pain associated with a palpable mass, skin change, or nipple/areolar changes such as lesions, erythema, edema, skin discoloration, nipple inversion, and peau d'orange (dimpled, edematous appearance of the overlying surface of the breast, resembling the skin of an orange) on physical examination should be referred for diagnostic radiologic evaluation.10 The specific study chosen depends on the patient's age and symptoms and is ultimately determined by the radiologist.
Screening vs. diagnostic mammography
Understanding the difference between a diagnostic breast evaluation and screening breast evaluation is significant in initiating a timely and appropriate referral. A screening mammogram is a two-view, radiologic evaluation of the breast (four views total with craniocaudal and mediolateral-oblique views of each breast).12 The patient does not need to see a healthcare provider at this time because it is only a screening evaluation, and no other assessment is performed. According to the Mammography Quality Standards Act (MQSA), the radiologist must provide a written report to the primary care provider within 30 days.10
Diagnostic mammography consists of the mammogram with supplementary additional views, if needed, and must be evaluated by the radiologist on the same day of the procedure. Further assessment practices might include physical breast examination, ultrasound, ductogram, cyst aspiration, ultrasound-guided core biopsy, and sterotactic biopsy. The physician and/or NP in the radiology department will decide which additional assessment modalities are needed. This typically happens after the review of the mammogram, while the patient is still onsite. The plan for additional testing is typically made independent of the referring provider; however, if the patient has medical issues that should be addressed prior to additional testing being performed (i.e., patient is on anticoagulants, etc.), the patient's referring provider would be contacted. If the radiologist recommends another type of radiologic test be performed (i.e., MRI, CAT Scan, etc.), this is stated in the report and the referring provider would then order the procedure at his/her discretion.
Guidelines for screening and diagnostic mammography
The United States Preventive Services Task Force (USPSTF) advocates that women at average risk for breast cancer should begin biennial mammographic screening between the ages of 50 and 74.13 No changes have been made to the ACR guidelines or to the American Cancer Society (ACS) recommendations. The debate continues among professional organizations and the USPSTF regarding these recently published proposals (see Comparison of USPSTF recommendations and the ACS guidelines).
In 2008, the ACR provided the following guidelines for the performance of screening and diagnostic mammography10:
- Women age 40 years and older who are asymptomatic from a breast standpoint with a negative clinical breast evaluation should have a screening mammographic evaluation annually. The age these examinations should end is dependent on the health of the patient and the agreement between the patient and her provider.
- Women with breast implants should undergo annual screening mammographic evaluations. Depending on specific facility protocols, a diagnostic mammogram can be performed in these particular patients.
Women with a family history of breast cancer (first-degree relatives, especially with a history of premenopausal diagnosis) should begin screening earlier than age 40 (ideally 10 years before breast cancer occurrence in the family, but not before the age of 25) and be referred to a genetic counselor to discuss options for genetic testing, screening, and prevention.9,14
A diagnostic mammography is required if palpable mass or induration is present, skin changes have occurred, certain types of nipple discharge are present, and the patient is experiencing continual or focal pain or tenderness. Diagnostic mammography is also performed on patients with a prior Breast Imaging Reporting Data System (BI-RADS) 3 mammographic study. BI-RADS is a mammogram reporting method used by the ACR and was created to promote the transmission of accurate and comprehensive reports using standardized language for classifying mammographic findings. It includes seven assessment categories (see BI-RADS categories).10,15 BI-RADS 3 is probably indicative of a benign breast imaging category with recommendation for short interval follow-up. The American Society of Clinical Oncology (ASCO) recommends a posttreatment mammogram for patients with breast cancer at 6 months, followed by 12-month intervals if findings remain stable.16
MRI as adjunct radiographic assessment
Although mammography remains the gold standard for detecting breast cancer, MRI provides an adjunct radiographic assessment to mammography, which can be particularly beneficial for certain kinds of lesions. MRI can be used to screen high-risk, asymptomatic women or diagnose women with breast abnormalities. Patients should also be referred for a screening MRI after evaluation by a genetic counselor.17 Women who have been found to have more than a 20% lifetime risk of breast cancer, such as those who have a genetic predisposition for the cancer or a history of mantle radiation for treatment of Hodgkin disease, benefit most from MRI.17
Although using MRI as a screening tool can benefit many women, the ACR does not recommend routine screening of asymptomatic women at average risk for breast cancer as it has a large false-positive rate leading to potential overdiagnosis and unnecessary treatment.17,18 The current ACR recommendations for MRI include assessing the contralateral breast in patients with a new diagnosis of breast cancer.17 MRI has detected contralateral cancer in up to 10% of patients who initially presented with unilateral breast cancer.19 Supportive uses of MRI include the evaluation of the extent of disease (margins of tumor, presence of multifocality and multicentricity), residual disease, and response to neoadjuvant chemotherapy.17 In addition, MRI can assess patients with suspected breast cancer that is mammographically and sonographically occult, characterizing lesions in which mammography or ultrasound is inconclusive, and evaluating for suspected recurrence in patients who have undergone postoperative tissue reconstruction.17
Although professional organizations do not agree on the guidelines for breast evaluation in the female population, which creates confusion for providers and patients, NPs play an integral role by providing a detailed evaluation that includes patient education and promoting healthy behaviors and high-quality care. NPs are forging new ground with specialization in diagnostic technologies that provide a broader practice arena to improve the quality of healthcare and help decrease preventable deaths from breast cancer through promotion of early malignancy detection.
NPs who are specially trained can perform preliminary evaluation of mammographic studies with presentation to the radiologist for discussion, clinical breast examination, ultrasound evaluation, as well as the execution of ultrasound-guided core and stereotactic biopsies. The training is based on a year-long institutional-specific preceptorship under the direct guidance of a Board Certified Breast-Imaging Radiologist. This includes specific training and education in breast evaluation procedures, mammographic/sonographic interpretation, and the breast disease continuum. Following demonstration of competency in these areas, the NP is granted official hospital privileges to perform these skills under the constant supervision of a radiologist. The NP can also summarize conclusions of initial mammographic images before consultation with the radiologist. Collaboration with a physician then leads to constructing a plan for further mammographic imaging, physical examination, or ultrasound. If a biopsy is necessary, the NP can perform the procedure. The NP can discuss pathology results with the physician to determine needed referrals and follow-up, and then educate patients and provide guidance regarding diagnosis implications and plans for referral to appropriate specialties.