Dr Jackie Smilg of the Radiological Society’s sub-specialty group, the Breast Imaging Society of South Africa (BISSA), explains why mammography is the gold standard in early detection of breast cancer, even before physical symptoms develop.
Breast cancer constitutes around 25% of all cancers in women and will affect 1 in 29 South Africans in their lifetimes. This figure is even higher in urban communities in South Africa, where the incidence is as high as 1 in 8 according to National Health Laboratory statistics. This insidious disease saw 1.7 million new diagnoses in 2012 alone and continues to be the subject of intensive educational campaigns to encourage women of all ages and socio-economic backgrounds to subscribe to early detection and diagnosis.
As frightening as the “Big C” is to all people, the good news is that modern medical advances and early screening and diagnosis are seeing more women than ever before surviving and beating cancer with less aggressive and invasive treatment. Therefore the need for early and accurate detection simply cannot be emphasized enough.
Breast cancer screening
The goal of screening tests for breast cancer is to find it before it causes symptoms. Breast cancers found during screening exams are more likely to be smaller and still confined to the breast. The size of a breast cancer and how far it has spread are some of the most important factors in predicting the prognosis of a woman with this disease. As with all cancer screening, recommendations for breast cancer screening rely on a combination of factors involving evidence about the risk of the condition, the benefits and harms of screening and the cost.
The gold standard for screening breast imaging remains the mammogram. Mammography reported by radiologists is the foundation of early detection of breast cancer. Regular mammograms can often help find breast cancer at an early stage, when treatment is most likely to be successful. One of the greatest advantages of a mammogram is that it can find breast changes years before physical symptoms develop. Results from many decades of research clearly show that women who have regular mammograms are more likely to have breast cancer found early, less likely to need aggressive treatment and more likely to be cured.
It is also important to dispel the myths that the negligible doses of radiation used in modern mammography can possibly produce breast cancer or represent any danger to the body, including the thyroid gland. There is simply no scientific evidence anywhere to support this. The reality is that the overwhelming benefits of early detection afforded by mammography far outweigh any such misperceptions and myths.
New screening tech
The latest mammography technology, Tomosynthesis, has brought an entirely new dimension to the fight against breast cancer. Digital tomosynthesis creates a 3D picture of the breast using X-rays. Contrast Mammography, where contrast investigates the vascularity of a lesion, is a new addition to breast imaging and promises to be a valuable problem-solving tool. Adding annual screening tomosynthesis to 2D mammography beginning at age 40 is highly cost-effective compared with 2D mammography alone, according to a study published in the American Journal of Roentgenology in August 2016.
In women with a significant family history of breast cancer or special circumstances, mammography can also be followed by ultrasound in both screening and symptomatic examinations and breast MRI.
Early detection is key
Early breast cancer detection reduces deaths, extends life expectancy, and improves life quality. Early breast cancer detection through mammography also enables less extensive surgery, fewer mastectomies and less frequent or aggressive chemotherapy.
The Radiological Society of South Africa (RSSA) and BISSA agree with international organisations, warning that any over-diagnosis claims are vastly inflated due to key methodological flaws in many studies. It is important to point out that as shown by international studies, the vast majority of the 10% of women returned for further examination following an inconclusive mammogram, simply received additional mammographic views or an ultrasound for clarification. Only 1-2% of women were required to undergo a needle biopsy as a result of a screening mammogram.
The short-term anxiety that could come from an inconclusive test result simply doesn’t outweigh the thousands of lives saved each year by mammography screening. Ultimately any inconclusive result warrants further and deeper investigation. Women should decide for themselves whether the short-term anxiety outweighs the risk of dying from breast cancer. When it comes to dealing with a potentially life-threatening disease as pervasive as cancer, it makes absolute sense to opt for the most effective, decisive and conclusive screening technology, which remains the mammogram.
The RSSA/BISSA encourages all women to start regular mammography from the age of 40 and continue to do so every year until age 70, regardless of whether they have symptoms or have an abnormality – early detection is the key objective. Women at high risk, usually due to a history of breast cancer in a close family relative, should have annual mammograms and MRI, starting at an age five years before the age their family member was diagnosed with breast cancer or at 40 years – whichever comes first. High risk is defined as a lifetime risk > 20-25%. Your doctor will help you calculate this or it can be done online here.
Women should regularly check their breasts for any irregularities and have a clinical breast examination by a GP or gynaecologist at least once a year. Any abnormality, regardless of age or family history warrants an immediate medical consultation with a healthcare professional. Many lumps may turn out to be harmless, but it is essential that all of them are checked.