What is a "family at risk"?
Having a previous family history case, particularly a direct one, is not proof of being a "at-risk" person, despite what is commonly thrown at women as a scarecrow.
We receive frequent testimonials from young women who have been unnecessarily alarmed and, more importantly, compelled to undergo unnecessary and potentially dangerous over-medication.
What about genetic mutation testing for women? When should it be done?
The independent publication Prescrire, Volume 36 N°388/February 2016, presents this topic.
BCRA1 and BCRA2 gene mutations are autosomal dominant, and women with these mutations have a more considerable and earlier risk of breast or ovarian cancer than the general population.
-For the BRCA1 mutation, the median age of onset is 40 years, and the cumulative risk of developing cancer at age 70 is 51 percent to 75 percent.
-For the BRCA2 mutation, the estimated cumulative risk ranges from 33% to 55%.
According to the journal Prescrire, the following criteria should be considered when proposing an oncogenetic consultation:
-Three people in the same branch with breast cancer before age 70,
-Two people in the same branch with cancer before age 50
-One person with ovarian cancer
-One person with breast cancer diagnosed before age 40, or a bilateral form, the first before age 50, or a hormone receptor-negative cancer that occurred before age 60.
The oncogenetic consultation will be requested in these circumstances, based on the score table below.
The Eisinger score is a decision aid for requesting an oncogenetic consultation.
We present it below (downloadable):
In families where there are multiple cases of breast cancer, the following conditions may arise:
A- Mutation found in a woman of the family presenting breast cancer.
This genetic mutation search provides valuable information to women in the family
Women who are carriers have a higher risk, while women in the same family who are not carriers have the same risk as to the general population.
Suppose a woman in the family decides to search for a mutation in the BRCA1 or BRCA2 genes because of her genealogy and finds herself to be a carrier of a deleterious mutation in these genes. In that case, her risk of developing breast cancer appears to be high, which is also high for her relatives.
B- No mutation found in women with breast cancer.
Either there is no mutation, and the patient has a form of cancer without a genetic cause, or there is a mutation, but it may be an unidentified genetic cause.
As a result, the women in her family will be uncertain whether or not this cancer is inherited. This cancer's risk of inheritance isn't as high as it is when a BRCA mutation is found, but it is higher than in the general population.
Because of the uncertainty, it's necessary to look into the genealogy, which has its own set of uncertainties and imprecision.
C- The breast cancer patient has not undergone genetic testing.
This provides useless information to women's relatives. The sick person may have had an unknown mutation, she may be mutation-free, but the mutation could be present in family members.
REMEMBER THE FOLLOWING:
- Either the person has a family member with a mutation but is mutation-free, her risk will be similar to the general population.
- Either she is a carrier of the mutation, and her risk of developing breast cancer can be estimated, which will be higher than in the general population.
- However, for certain women, there may still be a lot of uncertainty about their family's breast cancer risk:
*In women who have had breast cancer in the family but have not had a mutation in one of the cases,
*In women with a personal negative genetic mutation search, with a genealogy presenting several breast cancer cases, but without any search performed on the sick members.
Summary of guidelines according to the situation, based on the Prescrire publication.
Published in "La Revue Prescrire" May 2016/Tome 36 N°391-p.355 to p.361
The authors provided different options based on the risk circumstance (carrying a mutation, no mutation but one case in the family, no mutation but a family 'history'); we tried to synthesize these situations in a table (below, downloadable).
First of all, who are the subjects at risk?
-a woman with a case of breast cancer in a first-degree relative (mother, sister, daughter) before age 40.
-two women with breast cancer in the first or second-degree family.
-affected male relative, first or second degree
-woman of the family in the first or second degree affected by ovarian cancer.
When no genetic mutations are found in these families, the family risk remains quite uncertain.
For further explanation, see the article: https://cancer-rose.fr/en/2021/01/29/high-risk-of-breast-cancer-and-mammography-in-practice/
Who should be advised to have a prophylactic mastectomy (breast removal for the prevention of cancer)?
Synthesis of an article entitled "to whom to propose a prophylactic mastectomy" published in the journal 'Réalités en Gynécologie-Obstétrique- N°185_janvier 2017'; Authors: A.Kane, CH. Dehghani, E.Vincens from the Department of visceral and gynecological surgery, Groupe hospitalier Diaconesses Croix Saint-Simon, Paris
The conclusions are:
- For patients who are carriers of the genetic mutation (BRCA1 and BRCA2 mutation but especially BRCA1), unaffected, especially for young patients and those with a heavy family history, preventive mastectomy corresponds to the best means of prevention and must be discussed with them.
- For patients who carry a mutation or have a heavy family history and who have had breast cancer, preventive bilateral or contralateral mastectomy in the event of removal of the breast during first cancer seems to be of interest in terms of survival and reduction in the occurrence of second breast cancer. The HAS recommends it.
The benefit is very uncertain and highly overestimated for patients who have had breast cancer but without genetic risk or family history. The authors cite numerous risks, and it is NOT recommended.
Three cases are studied:
1. Request for preventive mastectomy of patients with mutation or at high risk.
2. Request for contralateral preventive mastectomy in these mutated or high-risk familial patients who have had first breast cancer.
3. Request for preventive mastectomy in patients who have had breast cancer without genetic background.
Lesions referred to as "at risk"
These are "borderline" lesions found on microscopic examination after a breast biopsy, which are not benign, which are not cancers in the strict sense of the word, which are said to be "intermediate" and which present a more or less increased risk for the patient of turning into cancer later on.
Below are two tables of recommendations found in the literature that quantifies risk based on a biopsy result.
These two tables indicate the proposed course of action (abstention, surgery, or monitoring).