How Can Family History Affect My Risk of Getting Breast Cancer?
Posted on 26th May 2022 at 11:27
If you have family members who have suffered from breast cancer, you may be wondering if it increases your chances of contracting the disease too. Unfortunately, there are increased risk factors if you have a first-degree relative with breast cancer. A first-degree relative is a mother, sister or daughter. Having a first-degree male relative with breast cancer also raises a woman’s risk. This article will explain in depth how family history can affect your risk of getting breast cancer and what preventative measures you can take to decrease your risk.
Family history of breast cancer
Interestingly, most women who get breast cancer do not have a family history of the disease. However, women who have close blood relatives with breast cancer do have a higher risk. Having a first-degree relative with breast cancer almost doubles a woman’s risk. And if you have two first-degree relatives, this then increases your risk three times. Women with a male first-degree relative who has or had breast cancer also have a higher risk of contracting the disease.
Some inherited gene mutations make a person more likely to develop certain types of cancer, including breast cancer. This means a gene mutation that is linked to cancer may run in the family. If you inherit a gene mutation like this from one of your parents, it doesn’t mean that you will definitely get cancer, but more acquired mutations could happen, which could then develop into cancer. The inherited gene mutation may allow this damaging mutation to build up faster.
At Naren Basu, there is a family history clinic that provides a family history cancer risk assessment. Six calculation models are used to help clinicians counsel individuals about their risk of developing breast cancer and/or the probability of detecting a mutation in the BRCA1/2 gene.
BRCA1 and BRCA2 genes
The breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes are the most commonly affected genes in hereditary breast cancer. Normally, BRCA1 and BRCA2 genes actually protect you from getting certain cancers, but mutations in the BRCA1 and BRCA2 genes prevent them from working correctly. If you inherit one of these BRCA mutations, you are more likely to get breast cancer. You and your family members are more likely to have a BRCA1 or BRCA2 mutation if your family has a strong history of breast cancer. At Naren Basu Breast Surgery, we have BRCA 1 and 2 testing services. There are three possible outcomes from the test:
1. Positive: Mutation is confirmed
2. Negative: No mutation identified
3. Variants of Uncertain Clinical Significance (VUS): ~4-5% of BRCA1/2 testing may result in VUS, further reduced in well-characterised ethnic populations. It remains best practice to ensure that both a positive and VUS result prompts a referral to the genetics services.
BRCA1
The BRCA1 gene (Chromosome 17) is involved in DNA repair. Approximately 1 in 500-900 women will have a mutation in the BRCA1 gene. Specific ethnic groups like Ashkenazi Jews will have a higher incidence of a mutation in BRCA 1 – in this group, it is around 1 in 40 women.
Having a BRCA1 mutation gives lifetime breast cancer risks of approximately 60-85%.
BRCA2
This is also a DNA repair gene (Chromosome 13). The lifetime breast cancer risk has a wider range (40-85%) compared to BRCA1. Approximately 10% of male breast cancer is associated with BRCA2 mutation.
Other risk factors of breast cancer
According to Cancer Research, breast cancer is now the most common cancer in the UK and the number one cancer in women by far. 1 in 7 women in the UK develops breast cancer during their lifetime. In 2017, there were around 54,700 women and 390 men diagnosed with breast cancer in the UK.
So, what causes breast cancer, other than having first-degree relatives who have had the disease? Having one or more of the following lifestyle risk factors increases your chances:
Being overweight or obese
Drinking alcohol excessively
Taking the contraceptive pill
Taking HRT (Hormone Replacement Therapy)
Being inactive
There are also these risk factors which you, unfortunately, cannot change:
Getting older
Having excessive X-rays or radiation
Being diabetic
Having dense breast tissue
Having benign breast disease
Having DCIS or LCIS (Ductal Carcinoma In Situ and Lobular Carcinoma In Situ)
Age of when your periods started and ended - you have an increased risk if your periods started before the age of 12 and if you went through menopause after the age of 55
High levels of sex hormones - oestrogen, progesterone and testosterone
Ethnicity - more common in white women
Height - taller than average women have an increased risk
Having children later in life or not at all
Ways to prevent breast cancer
There are simple lifestyle choices and changes that you can make to decrease your chances of contracting breast cancer:
Limit your intake of alcohol - have no more than one drink a day
Maintain a healthy weight
Keep active - aim for around 150 minutes a week of moderate aerobic activity or 75 minutes of vigorous aerobic activity, plus strength training twice or more a week
Breastfeed - the longer you breastfeed, the greater the protective effect
Limit postmenopausal hormone therapy
What if you’re at high risk of developing breast cancer?
If you have many risk factors associated with contracting breast cancer – especially those with a first-degree family history – you can opt to have some preventative surgery. Naren Basu specialises in risk-reducing mastectomies. The aim is to remove as much of the breast tissue as possible, but in reality, it is not possible to remove every single breast cell. However, the surgery reduces the risk of developing breast cancer by 85-95%.
In summary, family history does affect your risk of getting breast cancer but only through first-degree relatives. Lifestyle choices and other physical factors play a large role too. We hope you found this information useful and if you are at all worried about family history, please get in contact with us to discuss your options at our family history clinic.
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