Mammography

How does it help?

What are the advantages
of mammography?

In simple words, mammography is an 'X ray' of the breast. Different normal tissues of the breast and different tumours, will reflect these rays differently, giving rise to depth of white colour on the X ray. To understand mammography, let us first understand, what is a 'normal breast'.

Breast is made up of two types of cells - one is the 'milk system' (glandular tissue) containing the 'lobular' cells (which secrete milk) and 'ducts' (which transport milk towards nipple) and the other is the 'supporting fat' (fatty tissue) which contains blood vessels and lymphatics and other things to supply to these lobular cells and duct and provide nutrition to those cells and keep them healthy. There is no such thing as a 'standard' breast. The variation in size of breasts in different women is due to different proportions of fatty and glandular tissue. What is normal for one woman may not be for another. A mammography 'film' is like an Xray - black and white. Active glandular tissue is 'dense' and appears all 'white' on the mammogram whereas the fatty tissue is 'much less dense' and usually appear 'greyish' on the mammogram. Tumours in the breast - cancerous or non cancerous - usually appear white, and can be seen clearly against the grey of 'less dense' tissue, but not so easily against the white of a 'desne' tissue. Throughout a woman's life, the breasts will change; these are due to hormonal changes taking place in every woman's monthly cycle. Below are some descriptions of a normal breast at different stages of a woman's life:

  • Reproductive Period (15 to 45 or 50 years or so): Normal breasts feel different at different times of the month. The milk-producing tissue in the breast becomes active in the days before a period starts. In some women, the breasts at this time feel tender and lumpy, especially near the armpits. The breast is usually 'dense' in this period and mammograms will not easily pick up tumours and calcium spots. It is for this reason that 'screening' mammography is not advised below 40 years of age except in certain situations.

  • Post Menopausal: Activity in the milk-producing tissue stops. Breasts normally feel soft, less firm and not lumpy. The breasts may sag down a bit due to decrease in milk producing glandular tissue and increase in fatty tissue. The breast is much less dense now, and mammogram has high chances of picking up tumours and calcium spots.

  • Hormone Replacement Therapy (HRT): Some women have to resort to hormone replacement therapy after menopause due to post menopausal symptoms. As a result of the hormones, the milk producing tissue in breasts remain active. Hence the breasts appear dense on mammograms.

Instructions before undergoing Mammography

You must always keep the following points in mind before undergoing mammography:

  • Always inform the doctor about your present breast complaints. Any family history of breast cancer or taking hormone replacement therapy also needs to be known by the doctor.

  • Inform the doctor if you are likely to be pregnant as radiation is harmful to growing fetus.

  • It is best to undergo mammogram within a week of your periods.

  • Do not wear deodorant, talcum powder or lotion under your arms or on your breasts on the day of the exam. These can appear on the mammogram as calcium spots making it difficult to interpret.

  • Prior mammograms should always be carried to make comparisons with the present scans.

The Procedure of Mammography

Mammography Setup

A mammography unit is a rectangular box that houses the tube in which x-rays are produced. The unit is used exclusively for x-ray exams of the breast. It has a compression paddle to position the breast properly. There are newer machines called 'Tomography' which locate tumours with much more precision than standard mammography. In any case, we wont go too much into technical details, and focus more on how and when.

Mammography is performed on an outpatient basis. The procedure takes about 15 minutes. During mammography, the technologist will position the breast in the mammography unit on a special platform and is then compressed with a paddle. Many women find having a mammography uncomfortable or even painful, but this is normally just for a short time. However, some women may find that the pain or soreness lasts for a few days.
Why is compression necessary:

  • Breast compression is essential for good mammograms.

  • It diminishes patient movement hence better image acquired.

  • No superimposition of tissues hence lesions seen better.

  • Less radiation as lesser thickness of breast tissue needs to be penetrated.

  • Uniformly spreads out breast tissue hence tumourous tissue stands out better.

Usually 2 views are taken for each breast. i.e in all 4 radiographs are obtained. Additional views like magnification view, Cleopatra view or compression mammograms may be acquired, if required, depending from person to person. Also, an ultrasound of the breast is always done in addition to a mammography, and both, the ultrasound and film mammography are read together and the report is given.

Reading the Mammography Grading

The Radiologist, performing the Mammography (and additional Ultrasonography), will prepare the report, and in the end of the report, write a 'grading' indicating what he or she feels, the tumour is like - Is it cancerous or is it not? This grading is called the 'BIRADS' Category. It is usually graded from 1 to 5 (0 and 6 are also there)

  • BIRADS 0: Test insufficient - more testing may be needed, maybe by an MRI

  • BIRADS 1: No problems detected. Breast is perfectly normal

  • BIRADS 2: Some 'cysts' or 'benign' (non cancerous) tumours like fibroids found. Nothing suspicious.

  • BIRADS 3: Abnormal tissue or tumor found, but not too sure, need to repeat after 6 months.

  • BIRADS 4: The tumour looks suspicous. There is a chance this could be cancerous. A biopsy is needed.

  • BIRADS 5: Tumour is almost fitting into the cancerous category

  • BIRADS 6: Proven cancer

Advantages of a Sceening Mammography

  • Early detection of cancer: In women who have breast screening, most cancers are found at an early stage when there is a good chance that treatment will be successful. In India more than half of the breast cancers are discovered late when they have spread to the lymph nodes close to the breast or beyond that.

  • Screening mammography saves lives: Women who take part in breast screening reduce their risk of dying from breast cancer (by virtue of early detection of cancer.

  • Breast conservation surgery is possible: In women who have breast screening, any cancer is more likely to be found early. This means that the cancer is likely to be small and more likely to be removed by a lumpectomy (removal of the lump) rather than needing a mastectomy (removal of the whole breast).

Disadvantages of a Mammography

  • There is a public misconception that screening mammography detects all breast malignancies. It is important to understand that mammography can miss 10% of the cancers. It is less sensitive in dense breasts which are seen in young women or women taking hormone replacement therapy, and this is a major disadvantage, and it is for this reason that mammography is not routinely recommended for screening for women below 40 years of age.

  • Mammograms can be uncomfortable.

  • Mammograms involve x-rays. They only use a low amount of radiation. The radiation dose given by breast screening x-rays is continually monitored to make sure that it remains as low as possible, while still providing a good-quality image. However, if you start screening at a younger age, over your lifetime you will be exposed to more radiation. There is a very small risk that this could affect your health. The radiation dose for a standard two view examination of both breasts is app 4.5 mGy.

  • A screening mammography may not pick up all breast cancers. It is more likely that cancers will be missed (on mammography) in women who are under 40.

Ultrasound of the Breast

There are some limitations of mammography as we have seen above. An Ultrasound or UltraSonoGraphy (USG) plays an important role here. It is extremely important to 'characterise' the lump felt or seen on mammography when it does not have classic features of cancer.

Tumors in the breast can be of two types - 'solid' or 'liquid'. A solid tumor is like a 'round peppermint' - solid all around with no liquid or air. And a liquid tumour is like a 'balloon' - water inside, and a thin wall outside. Liquid tumors are called 'cysts'. It's important to see if the tumour is solid or cystic.

  • Pure cysts are very common (liquid throughout), and chance of them being cancerous is almost nil.

  • Mixed Solid Cystic Tumors: These are mostly cystic (liquid), with some solid element inside, on one side. In such, there can be a small chance of a cancer in the solid part.

  • Solid Tumors: Solid tumors are very common. Not all are cancerous. In the young, they are mostly fibroids. As the age increases beyond 30 years, the chances of them being cancerous also increases. After age of 50 years, most newly detected solid tumours will be cancerous.

An Ultrasound of the breast helps to differentiate whether the lump is solid or cystic (liquid), especially in younger women with dense breast tissue, where mammography is not fully reliable. Then, if it is solid, it tells us about the 'character' of the tumour - both cancerous and non cancerous tumors have certain typical features on an Ultrasound. Non cancerous (Benign) tumors tend to be very well defined, with regular margins. Cancerous tumors tend to have irregular shape, irregular margin, shadowing and calcifications. Cancerous lesions are usually taller than wider and may show small satellite nodules adjacent to lump.
Ultrasound can also identify the axillary nodes that are involved by the cancer with reasonable accuracy.

MRI of the Breast

Mammography (or Tomography) with Ultrasound suffices for the vast majority of women detected with breast cancer. But in some of them, either a mammography is not advisable (like some BRCA positive women) or because of other issues, mammography is less sensitive. In such situations, we recommend an MRI for them. Following are some of the indications for an MRI:

  • High risk patients having BRCA 1, BRCA2 genes or Cowden's syndrome or Li Fraumeni syndrome

  • Lesion characterization, if mammography is not clearly able to delineate

  • Multicentric tumours

  • Response to neoadjuvant chemotherapy, to see and assess if there is any remaining tumor

  • Axillary node metastases with an unknown primary

  • Postoperative tissue evaluation

  • Silicone and non-silicone breast augmentation

My Comments on Mammography


Mammography is a remarkably safe test. The risk of Radiation is almost negligible. There are supporters and opposers of mammogaphy for screening, both having their own valid views. But for a country like India, where awareness of breast cancer is at rock bottom, it remains safer to encourage people to do a mammography, since, that will offer one point of contact for the lady with a doctor and any lump, if present, will be picked up. Once breast cancer awareness reaches significant proportions, and we can rely on women to report when they feel lumps, we can definitely consider reducing doing mammograms then (for those who do not agree about using it for screening); but till that time, a mammography in every year or two, under Medical guidance, for women above 40 to 45 years of age, will be life saving for India.


TOPICS IN THIS SECTION

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Journey of BC: Diagnosis


1. I feel a lump! - The first visit to doctor
2. Is it really cancer? - Confirmatory tests
3. What is the stage? - Staging and fitness tests
4. Will it be surgery first? or chemo first? - Treatment planning and sequence

Journey of BC: Surgery


5. Should I conserve or remove breast? - Choice of Surgeries for breast cancer
6. How long will be the surgery? - Admission and Surgery
7. Care after surgery - Precautions and guidelines
8. What next? - The Pathology Report

Journey of BC: Further Treatment


9. How many chemo cycles? - Chemotherapy Consultation
10. Is a PORT necessary? - ChemoPORT insertion
11. Will I be normal during chemo? - The Chemotherapy time
12. Is Radiation painful? - Radiation Therapy
13. Yes!! I did it! - Treatment is over
14. How frequently do I meet doc? - Follow up guidelines

Other Topics


Risk Factors - The Risk Factors for Breast Cancer
Symptoms of Breast Cancer - Know the Symptoms of Breast Cancer
Early Detection of Breast Cancer - The Guidelines

Mammography, MRI, Ultrasound of the Breast - You are presently on this page
Core Biopsy - The Procedure

Neo Adjuvant Chemotherapy (NACT) - For LABC
Sentinel Node Biopsy - How is it done?
Targeted Therapy - Trastuzumab
Hormone Therapy - Who gets it?