Breast cancer is the most common invasive cancer in women in the United States; it is estimated that there will be 287,850 new cases of breast cancer in the United States during 2022 with 43,250 deaths.1 Lives are extended and saved every day because of a robust arsenal of treatments and interventions available to those who have been given a diagnosis of breast cancer. And, of course, lives are also extended and saved when we identify women at risk and provide early interventions. But in busy offices where time is short and there are competing demands on our time, proper assessment of a woman’s risk of breast cancer does not always happen. As a result, women with a higher risk of breast cancer may not be getting appropriate management.2,3
Familiarizing yourself with several risk-assessment tools and knowing when genetic testing is needed can make a big difference. Knowing the timing of mammograms and magnetic resonance imaging (MRI) for women deemed to be at high risk is also key. The following review employs a case-based approach (with an accompanying ALGORITHM) to illustrate how best to identify women who are at heightened risk of breast cancer and maximize their care. We also discuss the chemoprophylaxis regimens that may be used for those at increased risk.
Rachel P, age 37, presents to establish care. She has an Ashkenazi Jewish background and wonders if she should start doing breast cancer screening before age 40. She has 2 children, ages 4 years and 2 years. Her maternal aunt had unilateral breast cancer at age 54, and her maternal grandmother died of ovarian cancer at age 65.
The risk assessment process (see ALGORITHM) must start with either the clinician or the patient initiating the discussion about breast cancer risk. The clinician may initiate the discussion with a new patient or at an annual physical examination. The patient may start the discussion because they are experiencing new breast symptoms, have anxiety about developing breast cancer, or have a family member with a new cancer diagnosis.
Risk factors. There are single factors that convey enough risk to automatically designate the patient as high risk (see TABLE 14-9). These factors include having a history of chest radiation between the ages of 10 and 30, a history of breast biopsy with either lobular carcinoma in situ (LCIS) or atypical ductal hyperplasia (ADH), past breast and/or ovarian cancer, and either a family or personal history of a high penetrant genetic variant for breast cancer.4-9
In women with previous chest radiation, breast cancer risk correlates with the total dose of radiation.5 For women with a personal history of breast cancer, the younger the age at diagnosis, the higher the risk of contralateral breast cancer.5 Precancerous changes such as ADH, LCIS, and ductal carcinoma in situ (DCIS) also confer moderate increases in risk. Women with these diagnoses will commonly have follow-up with specialists.
Risk assessment tools. There are several models available to assess a woman’s breast cancer risk (see TABLE 210-12). The Gail model (https://bcrisktool.cancer.gov/) is the oldest, quickest, and most widely known. However, the Gail model only accounts for first-degree relatives diagnosed with breast cancer, may underpredict risk in women with a more extensive family history, and has not been studied in women younger than 35. The International Breast Cancer Intervention Study (IBIS) Risk Evaluation Tool (https://ibis-risk-calculator.magview.com/), commonly referred to as the Tyrer-Cuzick model, incorporates second-degree relatives into the prediction model—although women may not know their full family history. The Breast Cancer Surveillance Consortium (BCSC) model (https://tools.bcsc-scc.org/BC5yearRisk/intro.htm) is the only model that includes breast density in the prediction algorithm. The choice of tool depends on clinician comfort and individual patient risk factors. There is no evidence that one model is better than another.10-12
Continue to: CASE