Principal Source: Smith RA, Cokkinides V, Brooks D, et al. Cancer screening in the United States, 2010: a review of current American Cancer Society guidelines and issues in cancer screening. CA Cancer J Clin. 2010;60(2):99-119.
Practice Points
- Starting at age 20, women should undergo clinical breast exam every 3 years and be counseled about awareness of breast changes.
- Average risk women should undergo clinical breast examination and screening mammography annually starting at age 40.
- Health care providers should inform women about the benefits and limitations of mammography and the potential for false positives.
- Women at high risk include those with inherited susceptibility to breast cancer or chest radiation at a young age. They should be screened with mammography and breast MRI annually starting at age 30.
Breast cancer is the most widespread cancer effecting women in the United States.1 The high prevalence and inherent “cost” of breast cancer mandates physicians to be aware of effective screening tools, existing guidelines, and potential adverse effects.
Mammography screening and improvements in breast cancer treatments have contributed to improved survival rates, but2,3 mammography screening has declined since 2000. Potential reasons for this decrease include:
- poor access to medical care
- fear of radiation exposure
- concern of undesirable test results
- anticipated pain
- misconceptions of cancer risk
- changes in recommendations regarding mammography screening.
Patients with psychiatric illnesses are less likely to receive mammography screening.4,5 Cancer patients with schizophrenia, particularly women with breast cancer, have an increased risk of mortality.6
Risk assessment
Age, genetic predisposition, and factors that affect endogenous estrogen exposure such as early menarche, late menopause, and nulliparity are among the most important breast cancer risk factors (Table 1). Explore these and other risk factors with your patient before making screening recommendations.
Tools such as the Breast Cancer Risk Assessment Tool (BCRAT) can assist in stratifying your patient’s risk. The BCRAT, available at www.cancer.gov/bcrisktool, takes into account, age, race, family history, and previous breast abnormalities. Women at average risk for breast cancer include those with an estimated lifetime risk of <15%. Women with an estimated lifetime risk of 15% to 20% are at moderate risk. Women >20% are at high risk and should consider more intensive screening (Table 2).7,8
Other examples of high-risk features include chest radiation therapy (eg, for Hodgkin’s lymphoma) between age 10 to 30 or a breast cancer 1, early onset (BRCA1) or breast cancer 2, early onset (BRCA2) mutation carried by the patient or a first-degree family member, which can leave patients more susceptible to breast cancer.
Table 1
Breast cancer risk factors
| Female sex |
| Older age |
| Genetic risk factors (eg, BRCA1 and BRCA2 gene mutation)–5% to 10% of breast cancers |
| Family history of breast cancer |
| Personal history of breast cancer |
| Race (eg, Whites have highest incidence, African Americans have highest mortality) |
| Certain benign breast diseases (eg, atypical hyperplasia) |
| Early menarche, late menopause |
| Prior chest radiation (eg, for Hodgkin’s lymphoma; especially age 10 to 30) |
| Nulliparity, late child-bearing |
| Oral contraceptive use |
| Hormone replacement therapy (combined estrogen/progesterone) |
| Not breastfeeding |
| Alcohol (2 to 5 drinks daily increases risk 1.5 times) |
| Obesity |
| BRCA1: breast cancer 1, early onset; BRCA2: breast cancer 2, early onset Source: Adapted from the American Cancer Society; available at www.cancer.org |
Breast cancer screening
Choice of screening is guided by an individualized risk assessment. For women with average risk for breast cancer, the major components of breast cancer screening are clinical breast examination (CBE) and screening mammography.
Breast self-examination is not routinely recommended by expert groups. The American Cancer Society (ACS) recommends that clinicians discuss the benefits and limitations of breast self-exam with patients. The National Comprehensive Cancer Network (NCCN) recommends that women maintain breast health awareness but no longer advocates instruction in self-examination.
CBE by a trained provider, when coupled to routine screening mammography, may add modest benefit in terms of detecting cancer. The ACS and the NCCN suggest CBE along with annual mammography for all women starting at age 40.
Mammography has been to shown to reduce breast cancer mortality.8 A United States Preventive Services Task Force (USPSTF) review found statistically significant reductions in breast cancer mortality for women age 39 to 69.9
Because the USPSTF found a small net benefit of screening mammography in women age 40 to 49, their recent guidelines recommend against routine mammograms for this age group. Instead, the USPSTF suggests that screening be based on individualized risk assessment and discussion of the benefits and risks (false positive tests, overdiagnosis, and psychological harms) of screening.10 Other groups continue to recommend annual mammography starting at age 40 for women at average risk (Table 2).