This is in continuation to my previous post ‘Criteria for Genetic Testing in Breast Cancer’. It is important for both patients and healthcare professionals to understand these definitions and their implications.
Sporadic Breast Cancer
Sporadic breast cancer is breast cancer with no other family history of breast carcinoma through two generations including siblings, offspring, parents, and both maternal and paternal aunts, uncles, and grandparents.
These patients do not require genetic testing for BRCA genes and risk-reduction procedures.
Familial Breast Cancer
Familial breast cancer is breast cancer with a family history of one or more first or second-degree relatives with breast cancer that does not fit the hereditary breast cancer definition given later. It is important to note that a patient with one or more first degree relatives with breast cancer in this familial breast cancer category has a substantial excess lifetime risk of breast cancer when compared with patients in the general population, who do not have affected first-degree relatives. A study found that risk ratios for breast cancer increased with increasing number of first-degree relatives involved (1.80, 2.93, and 3.90, respectively, for one, two, and three first-degree relatives).
As yet, genetic and environmental causes of familial (as opposed to hereditary) cancer are incompletely described. Some cases that demonstrate a familial pattern are found on germline testing to have BRCA1 or BRCA2 mutations, and it is difficult to know exactly where to set the threshold for genetic testing. However, quantitative risk assessment of breast cancer is extremely useful for the familial category of at-risk women and guides medical decision-making about chemoprevention, high-risk surveillance using breast magnetic resonance imaging (MRI), and prophylactic mastectomy.
Patients with increased risk should undergo the BRCA test and if they test positive, they should be counselled about risk reduction techniques.
Hereditary Breast Cancer
Hereditary breast cancer is characterized by a significantly earlier age of onset of breast cancer (before 45 years of age), bilateral breast cancer, a greater frequency of multiple primary cancers such as cancers of the breast and ovary in the HBOC syndrome(Hereditary Breast and Ovarian Cancer Syndrome), and an autosomal dominant inheritance pattern for cancer susceptibility (multiple family members with breast or ovarian cancer).
These patients should undergo BRCA testing and should be counselled about the various risk reduction techniques (which I will be discussing in my next post).