A number of factors contribute to cancer, and in some cases there is the participation of a hereditary component, as can be the case with breast and ovarian cancer. Dr. Monica Zuradelli, specialist in Medical Oncology and Hematology in Humanitas, spoke about family history and genetic predisposition in breast and ovarian cancer during Mamazone 2017, the seventh edition of “Paziente Diplomata”, a day dedicated to women with and without breast cancer, organized by Humanitas last October 14.
Factors that contribute to cancer
“It is estimated that 8-10 women out of 100 will be diagnosed with breast cancer during their lifetime. The incidence of this cancer can vary in different age groups, reaching a peak between 45 and 60 years. Ovarian cancer, on the other hand, is much less frequent, with 1-2 out of 100 women receiving this diagnosis in the course of their lives.
The tumor is usually a multifactorial disease, its genesis is due to several factors, such as advancing age, smoking habits, sedentariness, but also dietary factors, chemical agents, infectious and prolonged exposure to UV rays. Then there are some cancers that can have a hereditary component, as happens in breast and ovarian cancer,” explained Dr. Zuradelli.
“The majority of breast cancers (about 70%) can be defined as sporadic, in the sense that several factors have collaborated in its genesis and development. There is also a smaller band (about 20-25%) that we can define as family-friendly because of the presence of the same disease in a single-family environment but not in direct relationship. True hereditary tumors with a genetic basis are a minor part, but it is not negligible (about 5-10%). In about 30% of the cases of hereditary tumors we are able to identify the genetic factor that contributed to the disease, in most cases these are genetic mutations involving the genes BRCA1 and BRCA2. These genes are located on chromosomes 17 and 13 of our hereditary heritage respectively and are called oncosuppressors because they are able to detect the presence of breaks or errors in the DNA double helix and activate repair mechanisms in the cell, allowing it to continue to replicate on a regular basis. However, in the presence of a mutation, these genes may lose the ability to control cell growth and therefore those who carry it pose a higher risk than the general population of developing breast or ovarian cancer,” the specialist points out.
“Therefore, oncogenetic counseling plays a fundamental role: in the course of an interview the doctors acquire a series of information about the personal and family history of the patient in order to reconstruct the family tree. Where possible, clinical documentation of family members with cancer should be reviewed to better define the course and recurrence of the disease. If indicated, genetic testing is prescribed and is carried out by means of blood collection’.
The genetic test and possible results
“The test can be positive when it highlights the presence of a genetic alteration; it can be non-informative when it does not show any mutation or it can show the presence of a variant with unknown meaning: an alteration, that is, to which currently, on the basis of scientific knowledge we have available, we are not able to give a precise meaning. In the last two cases, the patient is advised to carry out a series of controls (surveillance) that depend on his/her family history and to pay particular attention to his/her lifestyle (diet, physical activity), in order to reduce the risk of falling ill as much as possible.
If the test is positive, however, several preventive strategies can be discussed: surveillance and attention to lifestyle, preventive surgery (removal of the breast and / or tubes and ovaries) and “drug prevention”, or the use of drugs for preventive purposes, but in Italy it is not a standard practice and we can use it only within testing protocols.
The management of genetic testing is therefore very complex and given the different and possible implications of clinical-prognostic should be entrusted to a dedicated team of specialists,” concluded Dr. Zuradelli.
Watch Dr. Zuradelli’s full interview, click here