BRCA- associated breast cancer
Breast cancer is a disease in which the breast cells grow and replicate abnormally forming a mass called a tumour. In cases of breast cancer these tumours are ‘malignant’ and can spread to other sites in the body. As malignant tumours grow, they replace normal healthy tissue, which can be life-threatening, although prognosis varies greatly depending upon the age of the individual, the cancer stage at time of diagnosis and breast cancer type.
Breast cancer is very common and affects 1 in 8 women in the UK at some point during their life. Breast cancer is most common over the age of 50 years and the NHS National Breast Screening programme offers 3 yearly mammograms to all 50-70 year old women, with this age range extending to 47-73 in some areas. Men can also be affected by breast cancer, although this is rare. For more information on the risk of developing BRCA-associated breast cancer, see the table here.
BRCA mutations, particularly BRCA1, are associated with a greater risk of developing ‘triple negative’ breast cancer. Triple negative breast cancers generally respond well to chemotherapy if treatment begins at an early stage, but leaves patients with fewer treatment options than other types of cancer. Triple negative breast cancers account for approximately 10-20% of all cases of breast cancer with over one third of these cases occurring in women who are carriers of a BRCA1 mutation. For more information on triple negative breast cancer, watch this useful video.
Breast cancer associated with BRCA2 mutations is usually hormone receptor positive, although triple negative breast cancer can occur in association with BRCA2, particularly in post menopausal women.
BRCA- associated ovarian cancer
Ovarian cancer is a disease caused by rapid growth and division of cells within one or both ovaries. The ovaries are the reproductive glands that make the eggs (ova) and female sex hormones. Ovarian cancer is a general term that includes cancer of 30 different ovary-related tissue types. Though it can be life-threatening, disease prognosis varies greatly depending upon age of the individual, the cancer stage at time of diagnosis and also the cancer tissue type affected.
Ovarian cancer affects 1 in 72 women in the UK, occurring most frequently in women over 60 years of age, and does not affect men. For more information on the risk of developing BRCA-associated ovarian cancer,see the table here.
BRCA1 and BRCA2 mutations are associated with a greater risk of developing ‘high grade serous’ ovarian cancer. This is a form of ovarian cancer which arises from the cells that line or cover the ovaries. High grade serous cancer is one of the most common forms of ovarian cancer and is thought to originate within the fallopian tube. This form of cancer accounts for up to 70% of all ovarian cancer cases with approximately one quarter of these cases occurring in women who are BRCA positive. There is also evidence that ‘endometrioid’ ovarian cancer, which is characterised by disease in the womb, are also more common in women with BRCA mutations. Ovcare provides further information on types of ovarian cancer.
BRCA- associated prostate cancer
Prostate cancer is the most common cancer in men with over 44,000 new cases diagnosed every year in the UK. It is a disease of the prostate, a gland in the male reproductive system that secretes fluid that protects and nourishes the sperm. Prostate cancer usually develops slowly with few symptoms in the early phases of development. Advanced prostate cancer can spread to other parts of the body, which can be life threatening.
Prostate cancer affects 1 in 8 men in the UK, occurring most frequently in men over 70 years of age. Prostate cancer does not affect women. For more information on the risk of developing BRCA-associated prostate cancer, see the table here.
Although there is evidence that being BRCA positive increases the risk of prostate cancer, mutations in BRCA1 and BRCA2 are only found in a 0.44% and 1.2% of prostate cancer cases diagnosed at under 65 years, respectively. So, while the risk of prostate cancer is increased for men with these mutations, the majority of prostate cancer cases are not linked to BRCA1 or BRCA2 mutations. There is increasing evidence however that prostate cancer associated with such mutations may behave more aggressively and therefore should be considered for more radical treatment. Trials are ongoing to address this question.
Written by Jnetics.
Approved by Professor Rosalind Eeles Professor of Oncogenetics at The Institute of Cancer Research, The Royal Marsden Hospital London
Last review: 10.09.2016