Breast Cancer Risk Overview
Breast cancer is a complex disease and the cause is multifactorial. It arises from the interplay between age, an individual’s lifestyle which can be modified and their genetic makeup or inherited qualities which come from both parents. Over the last century, breast cancer has increased across all age groups and this may be due to changes in lifestyle. The risk of breast cancer for women over their lifetime in the UK is 1 in 7 and this risk is similar in the USA, Holland and developed countries. In parts of the world such as Sub-Saharan Africa the risk is much lower at 1 in 25. However immigrants who move from a country where there is a lower risk of breast cancer, to a country where there is a higher risk of breast cancer, will increase their risk within 2 generations of migrating there. This is probably due to changes in lifestyle and adopting those of the new country.
Breast cancer management is evolving and is focused on the individual characteristics of a person’s cancer. Some cancers have hormone markers on their surface where some of the newer drugs are targeted.
Familial Cancers
Breast cancer can run in families. Some families share lifestyles which may contribute to an increased cancer risk – such as alcohol intake, obesity as they age, lack of exercise.
However 85% of women with a first degree (mother or sister) relative with breast cancer, will not develop breast cancer. About 5-10% of all breast cancers are due to inherited genetic abnormalities from either parent. Breast cancer may be part of a genetic condition in the family, which may be linked to other types of cancers in both men and women. It is important to be aware of one’s family history of any cancer, the age of onset, the type of cancer, ethnicity (origins) of all four grandparents and any early deaths under 40 yr from ‘unknown causes’.
Some people don’t know their family history due to adoption or bereavement which is also important to mention.
In the late 1990s BRCA genes were discovered. These are genes which we all have which protect against breast cancer. In some families, there is a change (mutation/alteration) identified in the gene, which causes it to be faulty and no longer protective. In any woman with an abnormal (mutated) BRCA gene there will be a 50-80% lifetime risk of developing breast cancer. Despite this, lifestyle choices can improve this genetic risk. Therefore, treatment for breast cancer has become individualised, based on research of an individual’s different characteristics.
For those with a strong family history of breast and other cancers, the NHS runs special family history clinics. Your GP can refer you to this clinic. A detailed assessment of cancer in the family is made. If your risk of developing cancer is high then further tests can be done to look for abnormal genes which may run in your family. These genes include BRCA, PALB2, CHEK2, ATM and Tp53. When normal, these genes all help to repair your cell’s DNA. However if any are faulty then the risk of certain cancers is increased. The clinic also provides support and advice.
For those where there is a risk of passing on an abnormal gene (such as a BRCA mutation) to a baby, there is a technique available called Pre-implantation Genetic Testing (PGT). This involves a form of in vitro fertilisation (IVF). In the laboratory, the genes of the embryos are looked at and only those without a specific genetic fault are transferred to the womb (uterus). This will allow the baby to be born without that gene abnormality and therefore without the increased risk of cancer due to that abnormal gene.
LIFESTYLE FACTORS, CHOICES AND BREAST CANCER RISK:
DNA in the control centre, or nucleus of the cell , controls the cells’ function. If the DNA gets damaged or altered the cell growth and development can be altered and the cells can grow uncontrolled. This is what causes a cancer. Several lifestyle factors can affect your DNA and can increase the risk of getting breast cancer whilst other lifestyle factors have been shown to reduce the risk. Young women will leave school and go into either further education, work, travel or start a family and will then be responsible for their lifestyle choices. Having knowledge about the impact of different lifestyle factors is essential for all.
Continue reading these blog posts to find out more about lifestyle factor choices and breast cancer risk.