What is breast cancer screening?
Breast cancer screening refers to the investigation of a woman’s breasts for the presence of any malignancy early before the onset of any signs and symptoms.
In this screening process, specific investigations are carried out on an asymptomatic healthy woman to detect whether she has breast cancer or not.
This can help in early detection, and prompt treatment, and increase chances of good prognosis and cure.
The investigations that make up the breast screening process include the following tests.
- Clinical and self-breast examination
- Mammography or mammogram.
- In some countries (like the United States), the digital mammogram has replaced the conventional one.
- Breast ultrasound
- Breast MRI (magnetic resonance image)
- Genetic screening for breast cancer.
Breast screening aims at detecting breast cancer in the early stages, which helps to bring down breast cancer mortality rates and improve breast cancer survival.
Breast screening guidelines – Recommendations by age
In women under the age of 40 years, the demonstrable benefits of breast screening are not much. They should do a self-breast exam every month and get the feel of their breasts, which can make it easier for them to detect any abnormality, if and when it arises.
- In women over 40 years of age, a self-breast exam is advised regularly (every month) and a clinical breast exam by a medical practitioner is advised every two years.
- In women over the age of 50 years, along with a regular self-breast exam and clinical breast exam every two years, breast screening is advised at an interval of every two years.
- After the age of 70 years, breast screening benefits diminish and is not advised. However, self-breast exams and clinical breast exams are advised as before.
- In women with high breast cancer risks, more aggressive and more frequent screening as explained above is advised after the age of 40 years.
- In women with high cancer risks, we can include women with a family history of breast cancer, previous history of breast or ovarian cancer, or a confirmed BRCA mutation detected on genetic screening.
Note: A recent study conducted in Boston concluded that there could be a 60% lifetime reduction in breast cancer deaths if regular breast screening was done after the age of 40.
How do you screen for breast cancer?
Breast screening comprises the five following procedures:
1. Breast exam
The doctor carries out a clinical examination of the breast to feel for any lump or lumps in the breast. Visual examination of both breasts from the front helps to detect any differences in the size and shape of the two breasts. The doctor looks for any changes in the skin over the breast and for redness and swelling.
In a clinical breast exam, the doctor examines both breasts by hand to feel for any variation. He examines the breast in varying positions by placing the patient’s hands above the head and again by the side and again in a lying down position.
The doctor places the flat of the hand over the breast and palpates the breast to feel for any abnormal feel of a lump with the pads of the fingers. He also looks for the presence of any swelling in the axilla and above the collarbone. He squeezes the nipples to rule out any discharge.
Lumps that are smooth soft and movable are likely to be benign while lumps that are hard and fixed or attached are likely to be malignant. A breast exam can help in detecting a lump in the breast in the early stages and point to further investigations for diagnosis.
You could do a breast self-exam yourself more regularly once a month, which can enable you to detect a lump yourself
2. Mammogram
A breast mammogram, or breast cancer mammography as it is also called, is part of the breast screening procedure to rule out breast cancer. It is a low-dose X-ray imaging to detect any abnormality in the breast tissue.
Mammograms can detect even microcalcifications and small lumps that are not detected by clinical breast examination. You could read the post on mammography for details and images.
3. Breast ultrasound
As the name suggests, breast ultrasound makes use of sound waves to produce images of the breast tissue. The sound waves are not audible to the human ear.
They pass through the breast tissue differentiating normal tissue from the abnormal one. These sound waves are interpreted by a computer and translated into radiological images on the computer screen and stored. Read a detailed note on breast ultrasound.
4. Breast MRI (magnetic resonance imaging)
Breast MRI is a technique that uses magnetic and radio waves to produce images on the computer. It helps to differentiate between normal breast tissue and diseased tissue. It is safe for patient use.
According to a recent study, MRI conducted on women who were suspected of breast cancer in one breast detected cancer in the other breast in about 90% of the cases. You could read details in the post on breast MRI.
5. Gene testing for breast cancer
Gene testing is about identifying a cancer gene in a person through a blood test. BRCA1 and BRCA2 are a type of genes that give stability to the DNA in the cell and prevent mutation and uncontrolled growth of the cells. They are, therefore called tumor suppressors.
When these genes undergo mutation, or when they become cancer genes, there is a high risk of the woman developing breast cancer and ovarian cancer. The “BRCA” stands for breast cancer. Read detailed notes on gene testing to assess cancer risk and BRCA-gene testing for breast cancer.
After Breast Screening
On detection of any abnormality on breast screening, the doctor may order a breast biopsy to confirm the presence or absence of malignancy. A biopsy is a confirmatory test for the diagnosis of any cancer.
Benefits and risks of breast screening
The benefit of screening is it helps detect breast cancer early making it easier to treat and offering a better prognosis and chances of cure.
This procedure is not without risks
- A false-positive report tells you the abnormal finding is cancer when in fact it is not. This leads to expensive, invasive tests that take up your time and cause anxiety.
- Further tests can lead to overdiagnosis, resulting in overtreatment with surgery or radiotherapy and the subsequent side effects of these therapies. These can include pain and over-exposure to radiation.
Free breast screening
Many countries offer free breast screening for their population. Examples include:
- In some countries, like the U.K., the National Health Service (NHS) Breast screening program provides free breast screening for all women of age 50 years and above, every three years.
- Similarly, Canada has the Ontario Breast Screening Program (OBSP), which keeps inviting all women between the age of 50 years and 74 years every two years for free breast screening.