Medical Guides - Breast Cancer - Risk Factors

What Is A Family History

A family history suggesting an inherited link with breast cancer involves one or more blood relatives who develop breast cancer at a young age i.e. younger than 50 years. This can be on either your mother’s side or your father’s side or both sides.

How Does A Family History Affect Your Risk Of Developing Breast Cancer

Breast cancer is common and most women may have a family member with breast cancer but this may not increase your risk. For you to assess whether or not you have an increased risk, you need to know:
1. The number of relatives with breast cancer.
2. How close these relatives are - First-degree relatives are parents, children or siblings i.e. mother, father, sons, daughters, brothers and sisters. Second-degree relatives are aunts, uncles, cousins, nieces, nephews and grandparents.
3. The age of the family member when their breast cancer was diagnosed.
4. Any other cancers in close family members, especially ovarian.

Assessing Your Level Of Risk

Using the above factors we can divide the level of risk into three groups:

  • At or slightly above normal risk.
  • Moderate risk.
  • Potentially high risk.

The table below further expands on the categories above.









Group I : At Or Slightly Above Normal Risk.


Women in this group may either have:



  1. No confirmed relative with breast cancer.

  2. One first-degree or second-degree relative who developed breast cancer over the age of 50 years.

  3. Two first degree or second-degree relatives who developed breast cancer over the age of 50 years on either side of the family.

  4. One second-degree relative who developed breast cancer at any age.


NOTE: This represents 95% of all women in the population. 90% of women in this group will not get breast cancer. The relative risk over a lifetime is 1 in 12 to 1 in 8.


Management


You should:



  1. Have regular mammograms starting at age 40.

  2. Have annual breast examination by a Health Professional.

NOTE. You should see your gp or breast centre promptly if you have any breast change.


Group II: Moderately Increased Risk


Women in this group may have: One or two first-degree relatives who develop breast cancer under the age of 50 years. Two first-degree or second-degree relatives on the same side of the family with breast or ovarian cancer at any age.


NOTE. This represents 4% of women in the population.75 - 90% of women in this group will not get breast cancer. The relative risk over a lifetime is 1 in 8 to 1 in 4.


 


Management


This schedule should commence when you are five years younger than the youngest age at which your family member was diagnosed with breast cancer, or at age 40 (whichever is earlier).



  1. You should:

  2. Be seen at a specialised Breast Centre.

  3. Have annual mammograms. Have six-monthly ultrasound and clinical examinations.

NOTE. You should see your gp or breast centre promptly with any breast change.


Group III: Potentially High Risk


Women in this group may have:



  1. Three or more first-degree or second-degree relatives on the same side of the family with breast or ovarian cancer.

  2. Two first-degree or second-degree relatives on the same side of the family with breast or ovarian cancer diagnosed

    More information:


    Breast cancer

    Link to St Marks Breast Centre Online

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