Hi Roselover, it is nothing you have done.
Every single person on this planet has cancer cells in them. Most of the time, they stay tiny, less than half a millimetre and are kept at bay by our normal cell which attack them and they will never cause any harm. Then in some persons, cancer cells manage to grow and spread. We don't know why or what causes the trigger. We sometimes know how to stop them or shrink them, but one thing is sure, it is nothing you have done. Some will smoke two packets of cigarettes and the only green they have is the heineken beer and be fine all their life, others are vegan and will have cancer. Babies are born with cancer.
Science and research have identified triggers such as pesticides, processed meat, ... so in higher risk persons we should try to avoid all these.
Every person has his/her personal attitude. My sisters are more a wait and see, me I prefer to read, not only because it is fascinating but also because I feel in control.
I don't spend my days focusing on that, I have placed search alerts and from time to time I receive something in my mailbox and from there I follow up what interests me.
It also help with my condition. My body produces benign tumours but some could turn cancerous, so the more I know about cell growth (good and bad cells), the best I am and will look as these can be quite disfiguring if they become very large. So far so good, no spreading.
I have lived in different countries and approach and attitude differs widely. In Spain, where we were before moving to Australia, it is all about prevention, so you see an oncologist even if you don't have cancer. It was during one of those visit that the oncologist told me we all have cancer in us. In Australia, it is more a we will see once you have it. So I had to pay privately for the preventive diagnosis exams.
But even if it is nothing you have done, there are things you can do to decrease the probabilities genetic gave you.
The first and the most important is deciding for a single or double mastectomy. With your family history, I wouldn't really hesitate. Even without the gene mutation. The PALB2 was discovered less than 2 years ago. Words hasn't come very far yet. A GP Has to care for thousands of illnesses and can't possibly remember or even read every single medical article published.
Second, educate yourself, with internet you have no limitation. Of course, stick to good sources (universities, medical journals and science publications) and not a blog or pseudo health guru or whoever tells you to stop the treatment . I hate it when doctors say stay away from the internet, I would love to tell them they should spend more time on it. You can't do much about the why; shit happens is actually a good explanation, but you can try to do something about it.
Third, my experience and what I do, is mine alone. I am sharing it with you but I am not saying you should do it. Do (or don't do) whatever makes you feel confident and good. Id reading about it would make you freak out, don't.
Did they talk to you about IORT? Intraoperative Radiation therapy? Basically during the surgery while your breast is open and exposed you receive a massive dose of radiation straight in the cancer bed. As effective as 25 to 30 classic radiation sessions with a lot less side effects especially on the skin.
I am about to board the plane from Noumea to Sydney so can't really search for the medical articles, here is a quick link www.cancercenter.com/breast-cancer/iort/ and you can look for more detailed ones. It is not for every type of breast cancer but maybe it is worth mentioning it to the surgeon on Tuesday when you tell him about your decision.
Fingers and toe crossed for you and as we say in France, lots of merde.