Breast Cancer Awareness Month: What Increases My Risk?

Cancer / Women's Health

Each year, about 55,000 women are diagnosed with breast cancer in the UK. It is more common in women who are aged 50 and over.

Breast cancer can be invasive or non-invasive (in-situ). When people talk about breast cancer, they usually mean invasive breast cancer. This is when cancer cells have spread outside the milk ducts or lobules where they started into surrounding breast tissue.

We have information about non-invasive breast cancer called ductal carcinoma in situ (DCIS). It is the earliest possible form of breast cancer and is usually found during routine breast screening.

Breast cancer is likely to be caused by a combination of different risk factors. For example, getting older is one of the main risk factors for breast cancer.

What are risk factors?

The exact cause of breast cancer is unknown. But certain things can increase your chance of developing it. These are called risk factors. The risk factors for invasive breast cancer and ductal carcinoma in situ (DCIS) are similar.

Having one or more risk factors does not mean you will definitely get breast cancer. And if you do not have any risk factors, it does not mean you will not get it.

Breast cancer is likely to be caused by a combination of different risk factors, rather than just one.

Age

The strongest risk factor for invasive breast cancer is increasing age. About 8 out of 10 women diagnosed (80%) are over the age of 50. Breast cancer is rare in women under 30.

If you have had breast cancer before

Your risk of developing invasive breast cancer is increased if you have had breast cancer or ductal carcinoma in situ (DCIS) before.

In this case, you will have regular follow-up appointments. Any changes in the same breast or the other breast can be checked quickly.

Dense breast tissue

Dense breast tissue is when the breast is mostly made of glandular and connective tissue with very little fatty tissue. Women whose mammograms show dense breast tissue have an increased risk of breast cancer compared with women whose mammograms show mainly fatty tissue.

Hormonal factors

The female hormones oestrogen and progesterone can affect your breast cancer risk. Factors that can increase your risk include the following:

  • Taking hormone replacement therapy (HRT) for more than 5 years, especially if you are taking combined HRT (oestrogen and progesterone). When you stop HRT, your risk reduces again.
  • Not having had children.
  • Having had your first child after the age of 30.
  • Not breastfeeding your children, or breastfeeding for less than a year in total.
  • Starting your periods early (under the age of 12) or having a late menopause (after the age of 55).
  • Taking the contraceptive pill. But the risk reduces if you stop taking it.

Family history and breast cancer risk

Most women who get breast cancer do not have a family history of it. Or if you have only one female relative diagnosed with breast cancer over the age of 40, your risk is unlikely to be very different from other women the same age as you.

But sometimes breast cancer can run in families. The chance of there being a family link is bigger when:

  • a number of family members have been diagnosed with breast cancer or related cancers, such as ovarian cancer
  • the family members are closely related
  • the family members were diagnosed at a younger age
  • a man in your family has been diagnosed with breast cancer.

Fewer than 1 in 10 breast cancers (10%) are thought to be caused by a change (alteration) in a gene running through the family. In hereditary breast cancer, BRCA1 and BRCA2 are the two genes most often found to have a change.

Women with triple negative breast cancer are sometimes offered genetic testing. This is offered even if they do not have a family history of breast cancer. Most breast cancers caused by a change in the BRCA1 gene are triple negative. Your doctor or breast care nurse can explain more about this to you.

If you are worried about breast cancer in your family, talk to your GP or breast specialist. They can refer you to a family history clinic or a genetics clinic.

Lifestyle factors

Certain lifestyle factors may slightly increase your breast cancer risk.

Being overweight

The risk of breast cancer is higher in women who are overweight, particularly after the menopause. This is because being overweight may change hormone levels in the body. Keeping to a healthy weight can help reduce the risk of breast cancer.

Alcohol

Regularly drinking alcohol increases your risk of developing breast cancer. But the risk is small for women who drink within the recommended guidelines.

Smoking

Smoking may cause a slight increase in breast cancer risk. This seems to be linked with starting smoking at a younger age and smoking for a longer time. We have information on stopping smoking.

Cancer Useful Resources

LearnZone provides free and easy access to a wide variety of learning resources , online...
The Cancer Focus NI Well Aware service is aimed at the over 60s and is offered in a range...
Macmillan nurses are specialist cancer nurses with experience and qualifications in...
A healthy diet and regular physical activity may help you manage the effects of prostate...
After surgery and treatment for breast cancer, some women feel less confident about their...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...
There are a number of health campaigns throughout the year to raise awareness of...
Cancer Focus Northern Ireland’s Email Forum – or E Forum – helps us keep up to date with...
Going through cancer can be an isolating experience at any time, and especially when...
Fatigue support is a telephone programme which includes 4 appointments with a Specialist...
We rely on our incredible volunteers to help us spread the word about prostate cancer,...
Call us for free, unbiased, confidential support and information. There's no such thing...
‘Engage’ training is a comprehensive one day programme which seeks to address the current...
Cancer Focus NI’s Art therapy service is for anyone affected by cancer. Art therapy helps...
Bupa is working in partnership with Macmillan to offer up to 6 free one-to-one...
When an adult in the family is diagnosed with cancer it affects the entire family. It can...
The Sexual support service is a chance for you, or your partner, to talk to one of our...
We’re a community of people in the UK receiving immunotherapy treatment for bowel cancer...
Cancer Focus NI, Keeping Well vans are mobile drop-in units which bring health checks,...
Our nurses are here to help. They can provide you with information, and signpost you to...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...
The Macmillan Online Community is a free online place for people who are living with or...
There are so many ways to get involved, from cheering on a marathon runner to...
We’re a supportive and safe place for people with stage 4 bowel cancer living in the UK,...
Each month we run an online support group for men on active surveillance - a form of...
Zest for Life is a free 6-week programme led by a Cancer Focus NI facilitator. The course...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...
Someone is diagnosed every 15 minutes. What do you know about bowel cancer? Book a free...
We're always looking for enthusiastic people to help with our work. We have a range of...
Whether you need help defining sparse brows and lashes, caring for nails that are...
We have a team of trained volunteers throughout the UK who carry out talks to groups both...
There are hundreds of prostate cancer support groups in the UK. We have details of many...
Cancer Focus NI is the only local cancer charity to provide a free cancer information and...
Cancer Focus NI can provide a wide range of presentations to meet the needs of your...
Treatment for cancer may mean you have to make many visits to hospital to see your...
Macmillan Grants are a one-off payment of £350 to help with the extra costs that living...
As part of this community, you can talk about whatever you want, from diagnosis to...
Living with prostate cancer can be hard to deal with emotionally, as well as physically...
We know that money is a big and often difficult thing to talk about when you’re living...
The Quick Fit programme offers positive steps to improve your health through diet and...
Affected by breast cancer? Join this group to share experiences and ask questions to...
Writing is well-known to have therapeutic benefits – it gives you a voice and a way of...
Cancer Focus Northern Ireland’s Email Forum – or E Forum – helps us keep up to date with...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...
The important thing to remember when you’re affected by prostate disease is that you’re...
Welcome to the Caregiver Help & Support group. We're a supportive and safe place for...
Prostate Cancer UK have a team of trained volunteers throughout the UK who carry out...
Bowel Cancer UK Community — a place for anyone affected by bowel cancer to talk about...
Thrive is a community and safe space for younger women to connect with and support each...
When someone is diagnosed with cancer, they may experience feelings of shock, anger, or...

Cancer Articles & Videos

Cancer Helplines & Web Chats

Marie Curie - Helpline
Cancer Research UK - Helpline
Bowel Cancer UK - Forum
Bowel Cancer UK - Ask a Nurse
Macmillan Helpline
Cancer Focus - Nurse Line
Macmillan - Forum
Prostate Cancer UK - Forum
Macmillan - Ask an expert
Prostate Cancer UK - Specialist Nurse
Macmillan - Bereavement Forum