Genetic risk factors for breast cancer

• Genetic factors that affect breast cancer

  ~ If someone has an inherited faulty gene --> increases risk of developing certain types of cancer - sometimes more than 1 type of cancer

  ~ Faulty BRCA1 and BRCA2 genes --> increase the risk of developing breast, ovarian, pancreatic and prostate cancer

  ~ Although, many cancers aren't linked to inherited faulty genes (between 5 and 10 in every 100 cancers diagnosed are linked to an inherited faulty gene)

  'Faulty genes' are also called gene mutations
• BRCA genes 


  ~ Everyone has these 2 genes

  ~ BCRA stands for BReast CAncer gene

  ~ These genes are important as they stop the cells in the body from growing and dividing out of control

  ~ Doctors call these genes tumour suppressor genes

  ~ A mutation / fault in either of these genes means that the cells grow out of control - can lead to cancer developing

  ~ Faulty BCRA genes are rare - only 1 in every 400 people have a faulty BCRA1 or BCRA2 gene --> it can occur in both men and women
• BCRA genes with breast cancer 


  ~ Researches think that around 70% of women with a faulty BCRA1 or BCRA2 gene will develop breast cancer by the age of 80

  ~ Up to 10% of men with a faulty BCRA2 gene will develop breast cancer
• Other genetic factors that increase breast cancer risk

  ~ LFS (Li-Fraumeni syndrome) --> caused by a fault in the TP53 gene (controls when a cell divides, called a tumour suppressor gene)

  > People with LFS have an increased risk of developing breast cancer, as well as many other cancers e.g. bone cancer and brain tumours

  ~ PTEN Hamartoma tumour syndrome --> caused by a fault in the PTEN gene

  > Increases risk of developing benign tumours, breast cancer and other cancers e.g. womb and bowel cancer