Breast cancer screening: Clinical sciences

Chapters:

Watch video only

Introduction0:00–0:50

Breast cancer is one of the most common cancers among biological females globally. Although mortality rates have decreased over time, the incidence of breast cancer continues to increase every year.
Because most patients remain symptom free until the late stages, breast cancer screening plays a major role in early detection and treatment of the disease, thereby increasing survival rates.
Breast cancer screening focuses on identifying high-risk patients and utilizing imaging like screening mammography or breast ultrasound to evaluate for a mass.
The screening schedule and modality can differ based on the patient’s risk classification. When a patient presents for breast cancer screening, your first step is to assess for risk factors that can contribute to the patient’s future development of breast cancer.

Risk Assessment0:50–2:53

The first screening should occur between the ages of 25 and 30 as a part of their primary care visit. The majority of risk factors can be obtained through a detailed health history.
Then, you can use a validated risk-prediction model to calculate the patient’s risk of developing breast cancer, like the Breast Cancer Risk Assessment Tool, also known as the Gail model; and the Tyrer-Cuzick model.
The Gail model calculates the estimated risk a patient has for developing breast cancer within the next 5 years, as well as their lifetime risk.
It incorporates factors such as age; race and ethnicity; age at menarche; age at first live birth; age at menopause; history of breast cancer in a first-degree relative; and history of breast biopsies.
Similarly, the Tyrer-Cuzick model calculates a 10-year risk and incorporates factors like the patient’s age; body mass index, or BMI; age at menarche; parity; age at first live birth; age at menopause; history of hormone replacement therapy; breast density; BRCA mutation status; history of personal breast disease; Ashkenazi ethnicity; history of breast disease in a first-degree or second-degree relative; as well as a family history of ovarian cancer.
Using these risk factors, the models calculate the likelihood, as a percentage, of developing breast cancer. Now, patients with calculated risk greater than 20 percent are considered to be high-risk.

High Risk Screening2:53–4:13

For these patients, your next step is to assess their hereditary susceptibility. Patients who have a pathologic genetic mutation such as BRCA should have an annual MRI starting at age 25, and annual diagnostic mammography starting at age 30.
In addition, consider offering a clinical breast exam. On the other hand, patients who have a strong family history of malignancies should have annual diagnostic mammography starting at age 35, and possibly supplemental imaging with MRI and a clinical breast exam.
Any positive findings on imaging should be categorized according to the Breast Imaging-Reporting and Data Systems, or BI-RADS for short, which provides standardized interpretation, classification, and reporting of radiographic findings to determine the likelihood of malignancy.
Decision-making and management is then planned in accordance with the BI-RADS findings. Okay, before moving on to the remaining screening recommendations, let’s go through the BI-RADS guidelines.

BI-RADS Classification4:13–5:59

This guideline utilizes radiographic characteristics to categorize breast lesions into six categories based on their likelihood of malignancy.
Let’s start with BI-RADS 0. This classification indicates that the patient’s imaging information is incomplete based on the screening findings.
In this situation, you might need to obtain additional imaging to evaluate further. Next, BI-RADS 1 indicates a normal breast with no lesions, while BI-RADS 2 represents a benign lesion.
For these categories, regular screening every 1 to 3 years depending on the patient’s age is recommended. BI-RADS 3, on the other hand, indicates the lesion is probably benign, but requires additional follow-up like a clinical breast exam along with imaging in 6 months to evaluate for any changes.
A BI-RADS 4 lesion is considered suspicious for malignancy, while a BI-RADS 5 lesion is highly suggestive of malignancy.
Both types require either an image-guided core needle biopsy or an excisional biopsy for tissue diagnosis. Lastly, BI-RADS 6 indicates a biopsy-confirmed malignant lesion that requires a combination of surgery, chemotherapy, or radiation.

Average to Moderate Risk Screening5:59–9:19

Now let’s go back and talk about patients with a calculated risk of less than 20 percent and are at an average to moderate risk for developing breast cancer.
For these patients, your next step is to assess their age. For patients between the ages of 25 and 39, offer a clinical breast exam every 1 to 3 years.
If the exam is normal, they may continue their regular age-based screening; however, if there’s a palpable breast abnormality, your next step is to start a diagnostic work-up with a breast ultrasound, and in some cases diagnostic mammography.
Management of the mass should be based on the BI-RADS findings. Here’s a clinical pearl!
For patients with dense non-fatty breasts, or in situations where a noncalcified lesion is being assessed, three dimensional mammography is the preferred screening modality with average risk for breast cancer.
Three dimensional mammography combines multiple breast X-rays to create a series of imaging slices at different levels of the breast.
This provides greater sensitivity and specificity than two dimensional mammography and does not result in greater radiation exposure!
Next, for patients between the ages of 40 and 74, offer a clinical breast exam every year. If the exam is normal, offer mammography every 1 to 2 years starting at age 40, and then annually starting at age 50.
On the other hand, if you find a palpable abnormality on the breast exam, order a breast ultrasound with or without diagnostic mammography to begin your diagnostic work-up.
Any additional management should be in accordance with the BI-RADS findings. Lastly, for patients aged 75 or older, first assess their overall health status, comorbidities, and life expectancy at the time of your exam.
If your patient’s life expectancy is estimated to be less than 10 years, you may discontinue any further screening. However, if your patient’s life expectancy is greater than 10 years, continue to offer annual screening for breast cancer.
And here’s one final clinical pearl to keep in mind! Clinical judgment about screening for breast cancer involves balancing the benefits of improving outcomes and the potential harms of false-positive test results, overdiagnosis of lesions that are biologically indolent, and resulting patient anxiety.
This has led to differences in guidelines about the appropriate age to start and stop screenings, and how frequently to recommend mammography screening.
So, keep in mind that screening decisions should be made after discussion and informed decision-making that incorporate patient values regarding relative benefits and harms.
Alright, as a quick recap… Breast cancer screening plays a major role in early detection and treatment of the disease, thereby increasing survival rates.

Review9:19–9:53

The screening is based on the patient’s risk for developing breast cancer and utilizes both clinical exam and radiographic imaging to assess for a mass.
Management options after imaging is completed should be in accordance with the BI-RADS findings.