Breast Cancer Risk Assessment
There are multiple risk factors for developing breast cancer.
Almost 80% of breast cancers occur in women aged 50 years and above. Some reports have suggested that younger women are increasingly being diagnosed with breast cancer – approximately 1 in 5 breast cancers are in women under the age of 50 years.
Multiple factors may be driving this including having children later in life and increasing alcohol consumption.
Women are more likely to get breast cancer compared to men. Almost 1 in 7 women will get breast cancer in the UK, compared to 1 in 870 males.
A family history of breast cancer and other cancers (e.g. ovarian cancer) is a strong risk factor for developing breast cancer. Approximately 5-10% of breast cancers are thought to have a heritable component. Genes form the building blocks for DNA and control a number of functions including cell division. They (genes) are passed down through the generations and alterations in genetic material can cause changes to the cell division resulting in uncontrolled growth and ultimately the development of a breast cancer.
Having a first degree relative with a breast cancer at a younger or having a first degree male relative with breast cancer significantly increases the risk of developing breast cancer. Distant relatives have less of an effect on risk. Our family history clinic can assess you level of risk by taking a full family history as well as looking at additional risk factors.
The density of the breast tissue on a mammogram (breast x-ray) is an important risk factor for developing breast cancer. We are able to calculate a percent mammographic density (PMD) and use this information as part of breast cancer risk assessment.
It is thought that dense breast tissue has much glandular tissue within it compared to less dense breast which is more fatty in nature. As one gets older, breast tissue changes from being more dense (difficult to see on a mammogram) to more fatty (easier to see on a mammogram). This is why we do not routinely recommend mammograms in women under the age of 40 years.
Women with a density in 75% or more of their breast tissue have a 4-6 times increased risk of developing breast cancer compared to a woman with little or no breast density. We now have the ability to score the breast density of current or recent mammograms and use this as part of a breast cancer risk assessment that includes genetic testing and a brief history.
Body Mass Index
The association of breast cancer and obesity is seen mainly in post-menopausal women. In a group of 100 women with a healthy weight range, approximately 9 women will end up being diagnosed with breast cancer. In a group of 100 women with considered to be obese, 11 or 12 will be diagnosed with breast cancer. Unfortunately, being overweight is also associated with increased rates of recurrence and death from breast cancer.
Screen detected breast cancer
In the UK, the National Health Service Breast Screening Programme will invite women aged 50-70 years for a mammogram every three years. Some health providers (Well Woman Check / BUPA check) will offer annual breast screening to their employees from the age of 40 years. The hope is that we can diagnose breast cancers when they are smaller with a better outcome.
As a result of improving imaging technique, we can sometimes pick out other changes in the breast that may not amount to breast cancer. This can be particularly daunting as we may need to recommend biopsies and on occasion repeat biopsies to establish a diagnosis.
For women seeking a second opinion about a screen detected abnormality or cancer, we would need to have access of your screening mammogram and report to ensure we are reviewing the same area of the breast that was recalled by the screening service.
The Coronavirus pandemic has meant that breast screening was suspended for a number of months. There is growing concern that a large number of breast cancers are yet to be diagnosed – a significant proportion may be in the screening population.