Screening tests and diagnostic tools
In this section you will have an overview about screening tests and diagnostic tools. The actual process of diagnosis can take weeks and involves different examination tests. It is important to keep in mind that not every test fit in with every woman or lesion.
Screening tests:
Screening tests are used to find breast cancer before it causes any warning signs or symptoms. Breast cancer screening tests include clinical breast exam (CBE) and mammography.
When something abnormal is found, a follow-up is needed and your medical provider can ask for diagnostic test to find out if this abnormal tissue is cancer or not.
Diagnostic tools:
When you doctor performs a normal screening tests and finds something abnormal in your breast, it becomes necessary to do further tests to reveal a bigger picture and establish an accurate diagnosis. Waiting for results can be stresful and cause anxiety, but as earliest you have and accurate diagnosis, doctors can determine a personalized treatment for you.
Mammography
Mammography is the most widely used screening modality, with solid evidence of benefit for women aged 40 to 74 years. A mammography is an x-ray image of the breasts tissue and can be used for both screening and diagnosis.
Screening Mammography:
Is focus on look for any early signs of breast cancer. For women at average risk, screening mammography should be performed annually beginning at age 40 to check the breasts for any abnormal tissue.
Diagnostic Mammography:
Is focus on getting more information about a specific area of concern. This test usually takes more time as the technician needs several images to have an overview of the area to be assessed in detail by the radiologist, and the total dose of radiation is higher because more x-ray images are needed.
A technician will position your breasts for the mammography. Your breasts must be flattened to obtain a high-quality image. The whole procedure takes about 20 minutes. You might feel some discomfort when your breasts are compressed, and for some women it may be painful. Tell the technician if it hurts.
Although the mammography is the most common imaging test for breast cancer, some cancers may not be visible on the mammography, especially in women with or BRCA mutations. These are known as occult cancers and will result in false-negative mammography results.
Nowadays there is a newer technology known as digital breast tomosynthesis (DBT). DBT is a 3D digital mammography in which x-ray machines are used to take pictures and computer software reconstructs a 3D image. Although many women are offered DBT, it has not yet been confirmed whether it is superior to 2D digital mammography in terms of identifying early cancers and avoiding false-positives results.
What do I need to know about having a mammography?
POTENTIAL ADVANTAGES
First step of screening and breast cancer diagnosis.
Overall sensitivity 69.5 – 87.7%% (3)
Has been used during the last 50 years. Clinical evidence demonstrated that mammography in general reduces breast cancer mortality and advanced cancer. (4)
Low cost, as it is well established in clinical practice.
Low radiation
POTENTIAL DISADVANTAGES
Breast compression. Discomfort and difficult in breast implants or reconstruction.
Sensitivity will decrease to 33-40% (3-5) in women at high familiar risk (e.g. BRCA 1/2 mutations) and to 25–50% (6-12) in dense breasts.
When screening began at age 40 years, the cumulative probability of a woman receiving at least 1 false-positive recall after 10 years was 60%. (13)
Mammography has an overall sensitivity of 69.5 – 87.7%% for primary breast cancer detection. This means that mammographies miss about 20% of all breast cancers. False negative results.
DBT improve just a 5% on accuracy compared to 2D mammography. (14)
Overdiagnosis and overtreatment. (15)
Callback after a mammography
Just like any other kind of interpretation, reading a mammography is a skill that radiologists develop after intensive training and experience over time. They look for any signs of abnormality, including:
Asymmetries (something on one side that is not on the other)
Irregular areas of increased density
Clusters of small calcifications
Any area of skin thickening
Most of the time, a radiologist cannot ensure 100% if a lesion it is cancer or not based on a mammography alone, because both cancerous and non-cancerous growths can look the same, especially in dense breasts and post-procedural scars.
If you want to clear your mind and have a better diagnosis,
Ultrasound / Echography
A breast sonogram ultrasound uses sound waves from a hand-held probe to obtain a breast image. This may provide additional information or help clarify some of the abnormalities seen in a mammography.
It is useful for looking at some breast changes, such as those that can be felt but not seen on a mammography or changes in women with dense breast tissue. It also can be used to look at a change that may have been seen on a mammography.
Ultrasound can be used to differentiate between fluid-filled cysts and solid masses. (If a lump is really a cyst, it is generally not cancer).
A gel is put on the skin of the breast and an instrument known as a transducer is moved across the skin to show the underlying tissue structure. The transducer sends out sound waves and picks up the echoes as they bounce off body tissues.
What do I need to know about having a breast ultrasound/echography?
POTENTIAL ADVANTAGES
Non-invasive technique.
Can differentiate if a lump is a fluid-filled cyst or a solid mass.
Uses high-frequency sound waves, not radiation.
Provides real-time imaging, which makes it a good tool to help to guide a needle during biopsy.
Widely available and less expensive than other imaging methods.
POTENTIAL DISADVANTAGES
The use of the transducer makes ultrasound totally operator dependent. The technician may miss abnormal tissue if she/he is not well trained and don’t move the transducer through the whole breast.
Unable to detect microcalcification (small deposits that may indicate possibility of malignancy).
Need a well-trained professional to interpret the results and the interpretation can var depending on the evaluator.
Ultrasound results may identify a potential area of concern that is not malignant. These false-positive results could lead to more procedures, including biopsies that are not necessary. (16)
Ultrasound depends on the abnormality being recognized at the time of the scan as it is a real-time examination. This requires experience and good equipment.
Pressing the transducer to the breast for evaluating deeper areas, mostly where there is a lesion or the patient has a sensitivity breast, may be uncomfortable. Cold feeling of the gel is also possible.
When clear detection of a tumor is subject to interpretation, high technology and precision are essential.
If you want to clear your mind and have a better diagnosis,
Breast MRI
Magnetic Resonance Imaging (MRI) is a test in which multiple images are obtained based on the movement of some particles contained in the tissues under the effect of a strong magnetic field and combined with computational software analysis to generate the final images. A paramagnetic contrast agent (e.g. gadolinium) may be needed to improve image contrast and lesion enhancement.
A breast MRI is not used for screening in normal situations, but it may be indicated in high- risk individuals as a follow-up to an abnormal mammography or when mammography does not provide enough information, such as the case of young women and women with dense breasts.
Although the MRI can find some cancers not seen on a mammography, it is also more likely to find something that turns out not to be cancer (known as a false positive). False-positive findings have to be checked to rule out the presence of cancer.
For a breast MRI, you will lie face-down inside a narrow tube for up to an hour while the machine creates detailed images of the breast tissues.
You are likely to be told one of three things:
1. The suspicious area turned out to be nothing to worry about and you can continue with your yearly mammographies.
2. You should have another mammography sooner than 1 year – usually in 4 to 6 months – to watch it closely and make sure it does not change over time.
3. The changed area could be cancer and a biopsy is needed to know for sure.
You will also receive a letter with a summary of the findings that will tell you if you need more tests with or without biopsy, or when you should schedule your next mammography. This is why MRI is not recommended as a screening test for women at average risk of breast cancer, because it could mean unnecessary biopsies and other tests for many of these women.
What do I need to know about having a breast MRI?
POTENTIAL ADVANTAGES
Non-invasive technique (no radiation).
Is able to detect a very small amount of contrast agent, and has therefore a high sensitivity for primary breast cancer detection. (17)
In addition to mammography has been shown to be useful in evaluating women at high risk for breast cancer. (5,18)
MRI is used a pre-surgical mapping tool for the presence or extension of breast cancer as well as other distant lesions (metastasis).
POTENTIAL DISADVANTAGES
Uncomfortable for people who do not like small, tight spaces. May cause claustrophobia or anxiety.
Poor specificity (around 60% for invasive breast cancer). Do not distinguish clearly between normal tissues with contrast uptake vs. alignant tissue. It means a relative high incidence of false-positives results. (17)
Several contraindications including kidney diseases, allergy to paramagnetic contrast agents or implanted metallic devices. Make sure to inform your radiologist if any of these circumstances apply to you. (19)
Not recommended for diagnosis in ovulatory and secretory phase of the menstrual cycle and neither in the lactation breast period.
They cannot find breast changes as microcalcifications.
More expensive than Molecular Breast Imaging tests.
If you want to clear your mind and have a better diagnosis,
Molecular Breast Imaging
Molecular Breast Imaging (MBI) is a nuclear medicine technique capable of obtaining an accurate breast image after a radiotracer is injected into your blood.
The radiotracer is injected about an hour before performing the test. During that time, the tracer is avidly uptaked by the tumor. Molecular breast imaging devices are based on the ability to see the cellular uptake of the cancer cells, which have a higher uptake of the radiotracer than normal cells. This kind of technology provides very valuable functional information about your breast tissue.
Key studies have confirmed that MBI has a high sensitivity for detecting small breast lesions and is highly complementary to existing anatomical techniques, such as mammography, ultrasound and MRI. (20)
Molecular Breast Imaging can be either gamma-imaging technology or high-technology PET (Positron Emission Tomography) imaging.
What do I need to know about having an MBI test?
Although both technologies are similar in obtaining a functional image, there are some differences between having a gamma-imaging test and a PET test.
Gamma imaging: These devices use two panels to compress the breast and two scans positions are generally required to explore the breast; these provide a 2D image. The main radiotracer used to obtain the image is 99mTc-sestamibi.
PET imaging technology: is generally performed with a detector ring instead of two detector panels. Detector rings can image the breast in the prone position, and no compression is needed. It also provides your doctor with an accurate diagnosis in just one scan. The most commonly used radiotracer to perform the PET scan is 18F-FDG (a form of glucose), although there are other radiotracers upcoming for more specific molecular targets. Mammi is one of the available Molecular Breast Imaging technologies.
If you want to clear your mind and have a better diagnosis,
Whole-Body PET (WB-PET)
PET, or Positron Emission Tomography, is an imaging technique used to obtain images of the body identifying where cells are metabolically hyperactive in order to detect areas of cancer. A PET scanner is a ring of PET detectors and these studies are usually performed in the Nuclear Medicine department of a hospital.
A PET scan provides functional information instead of morphological information. This means that doctors would be able to visualize the amount of radiotracer uptake in the tissue instead of just the anatomical information.
For a PET scan, the most commonly used radiotracer is a modified form of glucose. This contains a radioactive atom and will be injected into your blood. The cancer cells absorb large amounts of the radioactive sugar, because most malignant tissues have an elevated metabolism. One hour after injection, the PET scan starts the acquisition to scan your body and highlight the areas with most radiotracer uptake. You will lie on a padded table, which moves through the ring into the scanner. The total dose of radioactivity is determined by the Nuclear Medicine Regulatory in every country.
What do I need to know about having a WB-PET scan?
POTENTIAL ADVANTAGES
PET provides images of functional processes.
Highly useful for looking for cancer spread to other parts of the body or to the lymph nodes.
WB-PET/CT allows fusion of both imaging modalities (morphological and functional).
Process is painless.
Information gained from PET exams is often unobtainable by other imaging techniques.
WB-PET can visualize cancer in complex cases or dense breasts.
WB-PET differenciates cancer from previous scar tissue.
Perfect technique for women with previous breast reconstructions or implants.
POTENTIAL DISADVANTAGES
It’s not sensitive enough to discriminate morphological structures.
Low sensitivity for subcentimetric (< 1cm) breast lesions, or lesions with a low radiotracer avidity. (21)
Higher radiation exposure to patients by combining PET radiotracer dose and the CT (computer tomography) exposure.
High dose of radioactive agent injected into the patient blood.
Radioactive agent injected into the patient blood.
The patient has to lie perfectly still while the images are being recorded.
Uncomfortable for people who do not like small, tight spaces. May cause claustrophobia or anxiety.
Results of diabetic patients may be affected because of altered blood sugar or blood insulin levels.
If you want to clear your mind and have a better diagnosis,
Biopsy
Finally, the only way to have a definitive diagnosis is to take a sample of tissue from the suspicious area and examine it under a microscope. The fact that you need a biopsy does not mean you have cancer. Most biopsy results are negative, but a biopsy is often the way to find out for sure. During a biopsy, a small piece of tissue is removed and checked under a microscope. The tissue sample is examined by a pathologist to determine whether or not cancer cells are present. The biopsy will result in a report detailing all of the pathologist’s findings. It is usual to use anesthesia for some biopsy procedures.
There are several different types of biopsies:
Fine-needle aspiration biopsy (FNAC): Your healthcare provider inserts a thin needle into the breast to take out fluid and cells from the suspect breast area.
Core biopsy: Also called Core needle biopsy (CNB), uses a needle to remove small pieces or cores of breast tissue. The samples are about a grain of rice in size. You may have a bruise and sometimes a small scar.
Vacuum-assisted biopsy (VABB): Is a newer way of performing breast biopsy. Uses a probe (thick needle) connected to a vacuum device to remove the sample of breast tissue. For vacuum-assisted breast biopsy, you’ll lie face down on a bed with special round openings in it, where you place your breasts. First, an injection of local anesthesia is given to numb the breast. This technique will produce a bigger breast tissue simple than either FNAC or CNB.
Surgical biopsy: Surgical biopsy is surgical procedure aiming to remove part, or all, of a lump, obtaining a simple to be studied under microscope. Sometimes your medical provider may do a surgical biopsy as first step, and other times, only if the sampre of a needle biopsy do not give enough information. When a sample of the breast tissue is removed it is called an incisional biopsy. When the entire lump is removed it is called an excisional biopsy.
The best way to confirm breast cancer is to have a pathologist report with a confirmation from the suspicious lesion.
Be sure to talk to your medical provider about the selected technique.
Remember: There is another less-invasive technique that can reduce the false-positive results from a misinterpreted MRI or mammography: Mammi.
If you want to clear your mind and have a better diagnosis,
