Early detection and screening for breast cancer

Breast Cancer is the most common cancer among women in the world and the disease is on the rise. It affects approximately 1 in 11 females in their lifetime. Based on data from Singapore Cancer Registry, 11,805 new breast cancer cases were diagnosed between 2011 and 2015.  This accounted for 29.4% of all diagnosed cancers in Singapore females, meaning nearly 1 in 3 cancers diagnosed were due to breast cancer. Breast cancer has also been the number 1 cause of cancer mortality with the greatest number of deaths among all diagnosed cancers in women.

When should one start?

The Singapore Cancer Society recommends that women as young as age 20 can start doing monthly self-breast examinations (BSE). BSE should be timed on a monthly basis 7-10 days from the start of your menstruation. If you have stopped menstruating, you can do your BSE on the same date each month.

*The images above were extracted from the Breast Cancer Foundation (Singapore). The full PDF file on breast self-examination can be found at this link.

Additional checks would be advised upon discovery of a lump. Lumps that look suspicious on imaging will then require a biopsy to determine the nature of the cells. The good news is the majority of breast biopsies do not turn out to be breast cancer. Follow-up and treatment may still be recommended by the doctor to manage the benign lesion. If cancer cells are found, a detailed report will be provided to determine the next steps in management. These include the tumour type and the tumour’s growth rate or grade.

Below is a list of the breast cancer screening technologies that might be included in the diagnosis process:

(i) Mammogram

A mammogram is a low-dose X-ray picture of the breast. It can detect the presence of cancerous lumps even before they can be felt with the hand. By compressing the breasts between the plates on the mammography machine, it is able to capture a 2D Image of the breasts with any underlying abnormalities within. Screening mammograms are routinely used to screen for breast cancer in women who have no specific symptoms. Diagnostic mammograms are done after suspicious results, abnormal physical findings,s or screening mammograms. The diagnostic mammogram is to determine if these suspicious or abnormal findings are indicative of breast cancer. Compared to a screening mammogram, diagnostic mammograms are more detailed.

However, no radiological examination is perfect and the mammogram is no different. Normal breast tissue, especially in females with denser breasts, can “obscure” or “hide” breast cancer.   Sometimes, an abnormality that looks like cancer may be picked up, but on further investigations, it turns out to be expected. Hence, doctors still emphasize the need for regular BSE, and regular breast screening mammograms to improve early detection rates for Breast Cancer. Furthermore, you may wish to consider upgrading your mammography to that of a 3-dimensional one if you have a history of dense breasts to further enhance the sensitivity of breast cancer screening. 

(ii) Digital Breast Tomosynthesis

Digital Breast Tomosynthesis (DBT), also known as 3D Mammography creates a 3D picture of the breast using XRays, rather than a 2D image. DBT ned 1 layer at a time instead of 1 flat image. DBT may be used together with 2D digital mammography as an additional tool in screening. To the patient, the DBT experience is very similar to a 2D mammography and the X-ray dose remains very low and under the guidelines of the FDA. To the radiologist who is the specialist reading the images, the DBT provides additional views of the breast to better analyse the breast tissue.

In essence, traditional mammography takes a single “picture” of one’s breast by compressing a 3D object into a 2D representation while tomosynthesis aims to reproduce the 3D image of the breasts. The machine achieves this by moving in an arc around the breast during the process and taking images from multiple angles. These images are then transmitted to a computer that assembles these data to produce a 3D image of the breast. 

There is still an ongoing debate and ongoing medical studies on whether detection rates for tomosynthesis are superior to conventional 2D mammography, but so far, results are encouraging and there are centres overseas that are adopting tomosynthesis more.

(iii) Ultrasound

A breast ultrasound is a scan that uses sound waves. The breast tissue deflects these waves causing echoes, which provide a picture of the breast tissue. It has the ability to differentiate between a mass that is filled with liquid from a solid mass. Ultrasounds are helpful when a lump is felt, and the images can be used to further evaluate the abnormality. It also helps to measure the exact size and location of the lump and analyse the surrounding tissue.

(iv) MRI

If initial diagnostic imaging is inconclusive, a breast MRI (magnetic resonance imaging) may be recommended. MRI uses magnetic energy and radio waves (not radiation) through the breast tissue to create a detailed picture that allows distinguishing between normal and diseased tissue.

A crucial step for every woman

The importance of monthly BSE and regular breast screening with your family physician cannot be overemphasized. Early detection does not prevent cancer but makes early intervention possible, with such, curative treatment can be instituted and this can increase the chance of survival, treatment options, and quality of life. No one method for women to use when checking their breasts is recommended over another. It is recommended that women of all ages, regardless of whether they attend screenings, are aware of how their breasts normally look and feel and report any new or unusual changes promptly to their general practitioner.