Breast cancer: am I at risk?
Written in association with:
Surgeon
Published: 27/07/2020
Edited by: Cameron Gibson-Watt
Your risk of developing breast cancer depends on many factors such as your age, family medical history, diet and lifestyle and where you live in the world. So, how do you know if you are at an increased risk of getting breast cancer? One of our top oncoplastic breast surgeons, Professor Kefah Mokbel, provides a comprehensive overview of the main risk factors of breast cancer.
Who is at risk of developing breast cancer?
As you get older your risk of developing breast cancer increases. For example, here we take a look at an average European woman and her chances of developing breast cancer over her lifetime:
a 25-year old woman has a 1 in 15,000 chance of developing breast cancer a 40-year old woman has a 1 in 200 chance of developing breast cancer a 50-year-old woman has a 1 in 50 chance of developing breast cancer a woman aged 80 years or over has around a 1 in 11 chance of developing breast cancer
In Western countries, the total number of breast cancer cases is five times higher than in Eastern countries such as China and Japan. Interestingly, studies have revealed that Japanese women who move to the USA increase their risk of developing breast cancer. This acknowledges that there is a significant environmental factor that plays a role.
What factors can increase your risk of breast cancer?
Risk factors are things that increase your chance of developing breast cancer. To better understand, we have grouped these breast cancer risk factors into 4 distinct categories:
Cancer history — your family history of cancer and whether you have previously had cancer Hormonal — the age you started your period, the menopause and how often you use the contraceptive pill Lifestyle — this includes obesity, your alcohol consumption and diet Other — genetics and environmental factors
Now, let’s take a look at these in more detail.
Cancer history
Family history of cancer
It is believed that up to 5% of all breast cancers are inherited due to abnormal genes being passed down from mother to daughter; so having a sister or mother with breast cancer will increase your chance of developing it too. There is a more significant link if the relative develops breast cancer in both her breasts or before she reaches the age of 45. A family history of breast cancer in a first-degree male relative is also associated with a significant increase in breast cancer risk. Breast cancer in a distant relative has little effect on your risk.
Your chance of developing breast cancer doubles if one first-degree relative developed the disease before the age of 45 years. If two first-degree relatives developed the disease before the age of 45 years, then your chance of developing breast cancer is four times greater than normal.
Scientists have identified several genes responsible for transmitting breast cancer. The most important of these genes are called BRCA-1, BRCA-2 PALB2, ATM, CHEK2 and P53. This inherited form of breast cancer usually develops before the age of 50 years. If a woman has not developed breast cancer by the age of 50 years, despite having a first-degree relative with breast cancer, it is unlikely that she carries the abnormal genes.
Ovarian cancer
The BRCA-1 gene is also associated with ovarian cancer. So, the presence of other types of cancer, such cancer of the womb or ovary, in addition to breast cancer, also suggests the possibility that there is a cancer-causing gene in the family. Testing for breast cancer genes is relatively simple using blood or a saliva sample after genetic counselling. One can be testing for a panel of 30 cancer-causing genes and obtain the result within 2 weeks.
A significant family history of prostate cancer or bowel cancer (early age of onset before the age of 55, more than one relative) is also associated with an increased risk of breast cancer.
Cancer of the other breast
If a woman has already had cancer in one breast, then the other breast is at an increased risk of developing the disease too.
Hormonal risk factors
Starting periods before the age of 11 years
If you started your period before the age of 11, you might have a higher risk of developing breast cancer. This is due to having a longer exposure to the female hormone oestrogen and this hormone is a well-established risk factor for breast cancer.
Late pregnancy
Your chances of developing breast cancer increases by 5% for every year there is a delay in having your first full-term pregnancy. If you have had your first child before the age of 50, then you already have a lower risk of developing the disease compared to women who had their first child after the age of 35. There has been recent research into breastfeeding and cancer, and so far, experts believe that breastfeeding reduces your risk of developing breast cancer.
Late menopause
Most women start menopause at around the age of 50. For those who start their menopause later, after the age of 53, have an increased chance of developing breast cancer. This is because, like starting your periods earlier, women starting menopause later have longer exposure to oestrogen.
The oral contraceptive pill
The oral contraceptive pill contains oestrogen. So if you have taken it within the previous 10 years your risk is slightly higher than a woman who hasn’t taken it. It is generally agreed that the greater the oestrogen-content in the pill, the higher the risk of developing breast cancer. However, what we have noticed is that breast cancer that develops in users of the pill seems to be less advanced than in non-users.
Hormone replacement therapy (HRT)
Taking HRT after the menopause appears to increase women’s risk of developing breast cancer, particularly if it is used for more than 10 years. HRT, however, reduces the risk of osteoporosis, bone fractures and developing large bowel cancer. Additionally, it relieves certain symptoms of the menopause, including vaginal dryness, hot flushes and depression. Therefore, we believe HRT shouldn’t be taken in women with a personal or family history of breast cancer. For those women who need HRT to improve their quality of life, I recommend using oestradiol patches or gel plus oral natural progesterone. If you have had a previous hysterectomy, then the progesterone is not needed.
Lifestyle risk factors
Obesity
Being obese after going through the menopause appears to increase your risk of breast cancer, however, obesity before the menopause seems to reduce breast cancer risk. In women who have gone through the menopausal, body fat is the main source of oestrogen production, whereas in pre-menopausal women the ovaries are the main source of oestrogen. Therefore, post-menopausal women who are overweight will be exposed to more oestrogen which increases their breast cancer risk.
Diet
It is thought that eating high levels of saturated animal fats and red meat, particularly when it is overcooked, increases your breast cancer risk. A Mediterranean diet that is high in fibre and vitamins A, C and E and contains lots of fresh fruit and vegetables, fish, olive oil, salads and nuts appear to be protective against breast cancer.
Alcohol consumption
Increased alcohol intake is generally associated with an increased risk of developing breast cancer and the risk appears to be the same with all types of alcoholic drinks.
Smoking
Research shows that both active and passive smoking increase your risk of breast cancer, particularly in women younger than 50 years old.
Other risk factors
The environment
Earlier we mentioned that women from Japan who had moved to the USA developed a similar breast cancer risk to that of Americans. This shows that there are significant environmental factors that are influencing women’s risk of developing breast cancer. Aside from diet and lifestyle, radiation exposure is a known risk factor of breast cancer and certain chemicals are thought to increase women’s risk, such as pesticides; however, there is no evidence to support this link yet.
Our habit of consuming high levels of processed foods, overcooked red meat and animal fats seems to increase the risk. As beforementioned, a Mediterranean diet is believed to be the most nutritious and risk-reducing diet.
Previous breast biopsy
The risk of breast cancer is not increased if you have had a previous surgical breast biopsy; however, if certain types of microscopic features are found in a biopsy it could be associated with an increased risk of breast cancer. There is a condition known as atypical epithelial hyperplasia, which is a precancerous condition affecting the cells of the breast. Your risk is increased by 4-5 times if it’s found.
Mammographic density
Having a mammographic density of 75% or more of the breast is associated with almost five times greater risk of breast cancer, and this risk persists for an extended period. For women with very dense breasts, the masking effect of dense breast tissue increases the odds more than 17 times of a cancer being missed and then detected by non-screening methods. In these cases, having an additional ultrasound and MRI scan should be considered.
Should I be worried if I am told I have an ‘increased risk’?
If you’ve been told you have an increased risk of developing breast cancer, then you will understandably be nervous or anxious. However, you should try to remember that the normal risk of breast cancer for an average European woman aged 30-50 years is around 1 in 1000 per year. If your risk were to double, it would be 1 in 500 per year; in other words, one woman in every 500 will get breast cancer within one year, which is still low, so you shouldn’t be overly concerned if you are told you have a higher risk.
If you are particularly worried about your risk of developing breast cancer, you should book a consultation with Professor Kefah Mokbel, by going to his Top Doctors’ profile and checking his availability.