family history vs gene positive

guineamom

My sis was just diagnosed with breast cancer a few weeks back, her diagnosis is very similar to mine in terms of stage and grade. I have been tested BRCA+, my sis did not want to do the gene test even after being diagnosed with cancer. Even without doing the gene test, all the girls in our family know we're high risk because of family history. Me and sis saw the same BS, the BS strongly recommended that I have a mastectomy but was not recommending that to my sis. Is being gene positive that much more significant than family history?

Beesie

The difference between carrying the gene and family history is 'certainty about risk' vs. 'lack of certainty'.  The risk levels might be the same, but with family history you simply can't know for sure.

You are BRCA+.  This means you are high risk.  There is no question about that. 

Someone who has family history might or might not be high risk. Most breast cancer is random, so having family members who've had breast cancer doesn't necessarily mean that you are also high risk - those cases could have been random.  Or, if those cases are genetic, without knowing the specific genetic link, there is no way to know if you've inherited it or not.  So family history potentially means that someone is high risk, but there is no way to know for sure.  So family history presents the potential that you may be high risk but there is less certainty. 

Your sister's situation is interesting.  She's not just dealing with family history but she is also dealing with her own diagnosis and knowledge that the BRCA mutation is in the family (since you, her sister, has it).  If she were to have the genetic test, there's a 50% chance that she would test positive.  Then she would know for sure that she is high risk, just as you are.  But if she were to have the test and she tested negative, then it would appear that her breast cancer might be random and not connected to the gene.  In that case, she wouldn't be higher risk (except for her own personal history of having being diagnosed).

How old is your sister?  If she is under 45 or even under 50, since you are known to carry the BRCA gene and since she has been diagnosed with breast cancer, the odds are probably pretty high that she carries the gene too.  And that would make her high risk.  But if she is older, there is a greater possibility that her BC could be random and not connected to having the BRCA gene.  

As you can see, it's complicated. 

guineamom

She is under 50.  Sis was really leaning towards mastectomy as she has 2 young daughters to worry about. I was just surprised that the BS was really hesistant when sis brought up possibility of getting a mastectomy. I thought with our family history plus the fact that I have been tested positive, BS would support sis's thinking of getting a mastectomy.

Mutd

Guineamom, the difference is huge. If your sister is negative, then her risk is NOT enhanced. Negative relatives in families with BRCA mutations have average risk, about as high as the women without family history. Dr. Steven Narod in Canada had a prospective study of women in BRCA families and reinforced this result. And several years earlier, there was a study in British BRCA families where they tried to find out if the risk is slightly increased in the negative relatives. The authors in the British study thought they saw some increase, but it turned out to be due to flaws in the study design (they enrolled too few families where the relatives didn't get cancer in the first place).

And if she is positive, then the risk from the mutation may be much higher than from the family history alone, and the interventions may be different too.

Could she make an appointment with a Genetic Counselor to discuss the risk, the tests, and all the other questions about it? Insurance should cover it w/o a hitch because there is a mutation in the family.

Mutd

You're right, to make a surgery decision, the mutation status may not make a big difference if there is a very strong family history. She should be able to choose mastectomy in either case. But the genetic result will give the surgeon more confidence that it's the best decision.

The difference in risks and treatments would become more important later. For example, different chemos work differently in BRCA+ and - situations. There are also clinical trials, like for "PARP inhibitors" which are said to work incredibly well in BRCA+ tumors. But without a positive gene test result, they may not enroll in the trial. And then there is ovarian risk which is strong with mutation, but not with family history alone.

4my4babies

I would see a different breast surgeon!!  Please do...it's YOUR health.  Not theirs.  I tested negative but have a sister who died at age 43.  I'll have DIEP in Nola next week and it honestly was not a difficult decision...more of a no brainer actually.  I realized very quickly that, once I started considering it, if I didn't do it and I later got breast cancer, I would have no one to blame but myself because I could have prevented it.  Not everyone agrees with the decision, but most anyone who as been the least bit affected by breast cancer does.  It may not be the right decision for everyone, but it certainly shouldn't be your doctor's decision...it should be yours.

There is a wealth of information on this site.  And at the FORCE sight.  Go to www.breastcenter.com and see the work they do.  Supposed to be the best in country and people come from all over to go there....those who had cancer and those like me, who haven't.

Good luck to you and your sister.  And God bless you both.