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Surveillance and Imaging Following Oncoplastic Breast Surgery
In this chapter, we will lay out the rationale for screening mammograms to start at age 40 and continued annually until age 70, at which time biannual imaging should be performed until life expectancy is less than 5 years, or a patient refuses intervention of any kind. Exceptions for high-risk patients are addressed later in the chapter. We will also list the current guidelines and recommendations set forth by our leading societies
Overview
In the United States, the 5-year survival rates for women with breast cancer have improved from 75% in 1975–1977 to 90% in 2003–2009. The risk of distant or metastatic disease and death increases with both tumor size and number of axillary lymph nodes involved. Although mammography is not a perfect test and may be particularly insensitive at detecting breast cancer among selected groups of patients, such as those with very dense breasts, extensive scaring from previous interventions (such as surgery and radiation), or those with a subtype of malignancy that is often harder to detect on imaging such as invasive lobular carcinoma, it remains effective at finding smaller tumors before they are palpable. When measuring the benefit of an intervention, as when measuring the harm, survival should not be the only measure of efficacy. After tumor size and lymph node involvement, survival is strongly influenced by tumor-related factors such as hormone receptor and human epidermal growth factor receptor 2, (HER-2) status, and grade. Screening mammography is effective at finding more (not all) cancers earlier, before they are palpable, and thereby reducing the number of women with cancers of advanced size and stage. Finding cancers at an earlier stage allows for better outcomes, more lives saved, and potential for both less extensive surgery and either no or potentially less extensive chemotherapy. Thus, mammography meets the criteria of an effective screening test: (1) detects disease at a stage when an intervention can make a difference, and (2) is affordable, accessible, and does not cause more harm than good.
Imaging in Women 40–70 Years of Age
Breast cancer is common, affecting about 1 in 8 women (12.5%) with more than 260,000 new cases per year in the United States. As of January 2018, there were more than 3.4 million women either with a history of breast cancer or being treated for breast cancer in the United States alone. Less than 1% of breast cancers develop in men. Not including benign breast biopsies and cosmetic breast surgery, there are more than a half-million breast cancer-related surgeries performed per year in the United States. In spite of all this breast cancer surgery, breast imaging recommendations remain controversial, with the United States Preventive Services Task Force (USPSTF) recommendations differing, in varying degrees, from most of our other guiding bodies: American College of Radiology (ACR), American Cancer Society (ACS), and American Society of Breast Surgeons (ASBrS)/Society of Surgical Oncology (SSO).
In part, the controversy arises secondary to the fact that breast cancer is not only common, it is potentially deadly but not uniformly so. Breast cancer represents about 20% of all cancers (men and women) and is the second most common cause of cancer death among women overall. This number continues to improve in women over 50, with breast cancer deaths having dropped by approximately 37% between 1989–2015 in this population ( Table 19.1 , with annex). Breast cancer screening guidelines from the various cancer organizations are listed in tables 19.2-19.4 . However, in women under 50, the death rate has remained steady since 2007. Data has also shown that younger women are more likely to develop more aggressive malignancies (HER2-positive and hormone receptor-negative) with higher risk of both distant and local recurrence.
Table 19.1
The USPSTF Average Risk Breast Cancer Screening Guidelines, 2015 59
| Population | Recommendation | Grade (What’s This?) |
|---|---|---|
| Women aged 50—74 years | The USPSTF recommends biennial screening mammography for women aged 50—74 years. | B |
| Women aged 40—49 years | The decision to start screening mammography in women prior to age 50 years should be an individual one. Women who place a higher value on the potential benefit than the potential harms may choose to begin biennial screening between the ages of 40 and 49 years.
Go to the Clinical Considerations section for Information on implementation of the C recommendation. |
C |
| Women aged 75 years or older | The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening mammography in women aged 75 years or older. | I |
| All women | The USPSTF concludes that the current evidence is insufficient to assess the benefits and harms of digital breast tomosynthesis (DBT) as a primary screening method for breast cancer. | I |
| Women with dense breasts | The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of adjunctive screening for breast cancer using breast ultrasonography, magnetic resonance imaging, DBT, or other methods in women identified to have dense breasts on an otherwise negative screening mammogram. | I |
| Grade | Definition | Suggestions for Practice |
|---|---|---|
| A | The USPSTF recommends the service. There is high certainty that the net benefit is substantial. | Offer or provide this Service. |
| B | The USPSTF recommends the Service. There is high certainty that the net benefit is moderate or there is moderate certainty that the net benefit is moderate to substantial. | Offer or provide this Service. |
| C | The USPSTF recommends selectively offering or providing this Service to individual patients based on Professional judgment and patient preferences. There is at least moderate certainty that the net benefit is small. | Offer or provide this Service for selected patients depending on individual circumstances. |
| D | The USPSTF recommends against the Service. There is moderate or high certainty that the Service has no net benefit or that the harms outweigh the benefits. | Discourage the use of this Service. |
| I Statement |
The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of the Service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined. | Read the clinical considerations section of USPSTF Recommendation Statement. If the Service is offered, patients should understand the uncertainty about the balance of benefits and harms. |
These recommendations apply to asymptomatic women aged 40 years or older who do not have preexisting breast cancer or a previously diagnosed high-risk breast lesion and who are not at high risk for breast cancer because of a known underlying genetic mutation (such as a BRCA1 or BRCA2 gene mutation or other familial breast cancer syndrome) or a history of chest radiation at a young age.
Table 19.2
American Cancer Society (ACS) 2015 Average Risk Breast Cancer Screening Guidelines
| Risk | Age | Recommendation |
|---|---|---|
| Average | 40-44 | Shared decision-making process for women to elect screening |
| Average | 45–54 | Annual screening |
| Average | Over 55 | Biennial screening |
| Elderly | Continued screening as long as life expectancy greater than 10 years |
ACS acknowledges definition of average risk is broad and excluded only:
-
History of breast cancer
-
Genetic mutation
-
History of chest XRT
Intermediate risk group that may require a different screening approach
Table 19.3
American College of Radiologist (ACR) Average Risk Breast Cancer Screening Guidelines, 2018
| Risk | Age | Recommendation |
|---|---|---|
| High Chest radiation before 30 |
Age 25 or 8 years after radiation | Annual screening |
| High-genetic based increased risk and their untested 1st degree relatives, those with >20% lifetime risk | 25–30 | Annual mammogram and consider MRI |
| High personal history of breast cancer | Start at diagnosis or 40 whichever comes first | Annual mammogram and if <50 consider MRI |
| High personal history of ADH, ALH | 40 | Annual screening and consider MRI especially if other risk factors are present |
| Average | 40–75 | Annual screening |
| Average | Elderly | Annual screening until life expectancy less than 5–7 years |
Without Tomosynthesis, should be performed annually.
ADH, Atypical ductal hyperplasia; ALH, atypical lobular hyperplasia; LCIS, lobular carcinoma in situ.
MRI should be considered, especially if other risk factors are present.
Table 19.4
American Society of Breast Surgeons (ASBrS) in Conjunction with the Society of Surgical Oncology (SSO), Breast Cancer Screening Guidelines
| Risk | Age | Recommendation |
|---|---|---|
| Average | 40–44 | Consider screening based on a discussion of risks and benefits |
| Average | 45–54 | Annual screening mammograms |
| Average | 55 and older | Annual or biennial screening for women 55 and older based on a shared decision |
| Average | Older than 75 with life expectancy greater than 10 years | Biannual screening mammogram |
| Asymptomatic Intermediate Risk | 40 and older | Consider use of annual screening mammography for women with greater than an estimated 15% lifetime risk for breast cancer |
| Asymptomatic High Risk | 10 years younger than the 1st degree relative, or 10 years after chest wall XRT, or by age 40, whichever comes first | Recommendations for asymptomatic high-risk women (20–25% or greater estimated lifetime risk) annual mammography and MRI compliant with ACS and NCCN guidelines |
Breast cancer is often thought of as a disease of the elderly, which is not untrue ( Figs. 19.1 and 19.2 ). However, this is a very limited picture of the true impact and distribution of the disease. Breast cancer is most commonly diagnosed in middle-aged women with a broad distribution extending to the young adult and the very old. As stated earlier, the “lifetime” risk of developing breast cancer is 1 in 8 women, with 25.9% of all breast cancers diagnosed between the ages of 55 and 64 with an average age of 62 at diagnosis (see Fig. 19.2 ). However, it is extremely important to note that there is an almost equal distribution 10 years above and below this, with 20.4% of women diagnosed between 45–54 years of age and 24.1% diagnosed between 65–74 years of age. Context remains extremely important as seen in Fig. 19.3 , with lifetime risk seen to be highest in women age 80; however, the age at which a large number of women are diagnosed is 62 (see Fig. 19.3 ). Again, we must note that survival improves with earlier stage at diagnosis; 5 years survival for stage I breast cancer is 98.7% compared with 27% for metastatic disease.
It is a known fact that the vast majority of breast cancers are spontaneous at 85–90% ; thus, lacking a family history cannot be interpreted as protective but rather just another unknown. Using lack of a family history as an indication for mammography exclusion before the age of 50 leaves a large and vulnerable group of “average risk” women with a misimpression that they are somehow safe and will not benefit from screening mammography. Thus, in context of previously presented information, what are the current recommendations for breast imaging set forth by the USPSTF and what is the rational for these recommendations? The original recommendations, set forward in 2002, used a meta-analysis of eight large prospective mammography trials designed to assess the effectiveness of mammography in reducing breast cancer mortality but only included data from seven trials. All the trials had limitations, but the USPSTF excluded the Edinburgh study from the analysis, secondary to imbalance between the control and screened groups. USPSTF concluded: “Mammography reduced breast cancer mortality among women 40–74 years of age with a greater benefit in women greater than 50” and at that time continued to recommend mammograms annually starting at age 40.
In 2009, the USPSTF updated their analysis to include data from the AGE trial from the United Kingdom that randomized women aged 39–41 to annual screening mammography until age 48. The purpose of their evaluation was to “determine the effectiveness of mammography screening in decreasing breast cancer mortality among average-risk women aged 40 to 49 years and 70 years or older, the effectiveness of clinical breast examination and breast self-examination, and the harms of screening.” They published their results in Annals of Internal Medicine , November 2009. The study used film and digital mammography, and the Task Force again found a 15% reduction in breast cancer mortality in favor of screening with an even greater benefit for women over 60. They reported the false-positive rate highest in women aged 40–49 with the highest rate of additional imaging and unnecessary biopsies in this age group. Secondary to their concerns for the harm benefit ratio, they changed their recommendations to consider starting mammographic screening at age 50. Further, they found no benefit for clinical breast examination, and self-breast examination was considered harmful.
In their conclusion, they stated that “Our meta-analysis of mammography screening trials indicates breast cancer mortality benefit for all age groups from 39 to 69 years, with insufficient data for older women. False-positive results are common in all age groups and lead to additional imaging and biopsies. Women aged 40 to 49 years experience the highest rate of additional imaging, whereas their biopsy rate is lower than that for older women. Mammography screening at any age is a tradeoff of a continuum of benefits and harms. The ages at which this tradeoff becomes acceptable to individuals and society are not clearly resolved by the available evidence.”
Of very significant import is that the USPSTF’s primary concern with mammography was not its ability to detect cancers earlier than would be found without imaging and thereby prevent breast cancer-related deaths, but rather harm of imaging outweighing the benefit based on unnecessary imaging and biopsies as well as costs. With this in mind, note their studies used plain films and digital mammography. We now have 3D breast tomosynthesis widely available, which has shown a reduction in false positives by 17.1% and an increase in the rate of cancer detection of breast cancers by 33.9% over standard digital mammography.
If we combine (1) the improved diagnostics of tomosynthesis with fewer false positives and better detection rate (2) with the proven, at least, 15% decrease in mortality with early diagnosis through mammography and (3) the fact that women under 50 account for approximately 24% of breast cancers diagnosed per year and tend at a productive time in life with young children contributing to society, (4) to have more aggressive disease that will progress rapidly and cost more to treat, (5) and are very unlikely to be considered “high risk” and thus quality for imaging under the current guidelines, a strong argument can made to resume annual mammograms starting at age 40.
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