In Your Opinion, What Causes DCIS?

For me, I blame the HRT I took.

I never took birth control pills though. I was always "pill scared." I actually got talked into taking HRT although I kept refusing even when ob/gyn. told me I had symptoms of very low estrogen. I finally gave in after 3 years of refusing. I had been taking them for 10 years and stopped at diagnosis. I changed ob/gyns and when I told my new ob/gyn that I had been on HRT she said: I won't let my women on that sh*****t.

The HRT must really mess up the breasts because I am about to undergo an op for this second diagnosis (opposite breast) and I asked my BS what it meant to have a new primary like I have and he told me that it means your breast tissue is unstable. So this is why I think the HRT must mess up the breasts because whatever it does to them, such as tissue change, or whatever, the effect of the HRT is still there in my particular case.

Boy, when I look back over my health history, I was so healthy, I was always physically active, had a great diet, can't stand  junk food, I kept away from pills until HRT and now my life has changed so much that I look back and realise that I really screwed up my life with that HRT. I have no health issues except this BC crap!

Estrogen has never been my friend. I had migraines every month before I got my period. I never could take birth control because they gave me instant migraines. Even though I had a hysterectomy in my 40's, my ovaries were left and I knew when I hit menopause because the headaches stopped. In January 2011. I started taking estrogen because of my hot flashes. In November I was diagnosed with DCIS that was Her+ and the onco said it absolutely could have come from the hormones. Wish I would have known that before I took them!

Wow, this is sure a question we ask over and over on this journey that we never chose!  My overall risk was low, non-smoker, no family history, reasonably healthy lifestyle etc, yet bc still got me...

In my case I wonder if it had something to do with infection.  At 39 I was breastfeeding my daughter and dealing with repeated bouts of mastitis (four, times before I finally got to a really good breastfeeding clinic to deal with a badly cracked nipple).  It was always my right breast with the most redness occuring on the upper part of my breast, slightly outward towards my underarm.  Fast forward three years to last summer when at 42 I went for my first ever routine screening mammo.  When they called me back to look more closely at the same area of my right breast I immediately assumed the masitis must have left some scarring or damaged tissue and that's all they were seeing.  Drs all said that was possible but they would like to biopsy just to be sure.  Never one to take chances I agreed.  Long story short, after a few procedures, and finally rmx, it turned out that I had had a 1cm DCIS tumor in what appears to be the same area as the earlier mastitis. 

I have done a moderate amount of research and found that in general, while some cancers are triggered by infection, I didn't find anything at all linking mastitis to bc.  Also, three years might be too short to grow a 1cm tumor, but then again, nobody can really say for sure.

 So, while it's tempting to make a connection, I don't really know if the mastitis played a role in my subsequent DCIS diagnosis.  Or is the reverse what actually happened: the tumour was already there and interfered with that duct's ability to fend off local infection?  Who knows.  I just thought I'd put it out there for awareness as maybe future research will provide more answers.

good question, no history of BC in my family although mom had lung cancer and brother has Hodgkins

but my mom took DES to become prego with my younger sister. Since sister does not communicate with me since my diagnosis, I do not know if mom took DES while getting prego with me.  Family that I am in contact with does not seem to know...or care, sad

anyone here know about DES daughters and BC?

Very good question.  I was diagnosed at age 54 and never took HRT.  I was on the pill for about two years in my early 20s.  My breasts are heterogeneously dense, so maybe that had something to do with my DCIS.  My weight has always been normal, I don't smoke,  and I had my first child at 28. 

At the time of my diagnosis, nobody else in my family had breast cancer.  In February, my first cousin (our dads were brothers) found out she had stage 1 breast cancer.  She's 60 and lives about 1,000 miles away from me.  Her doctor did some type of tests and told her it's not hereditary.  My doctor didn't feel it was necessary for me to have the BRAC tests done. 

I've changed some of the things I do.  For example, now store left over food in glass containers rather than plastic.  I've been exercising and trying to eat healthier.  Other than that, I'm not sure of what else I can do.

I wish we knew what caused this so we could prevent it.  Very frustrating!

I had a strange conversation the other day.  Someone asked me if I had every had a root canal.  This person is very much into holistic cures and natural products and said he had read some studies linking past root canals and breast cancer.  He asked me if I had ever had one.  Well, yes, two.  He said that there seemed to be a correlation with the root canal being on the same side as the cancer.  I have not tried to look this up, and I must admit, it does not seem very plausible to me.  Anyone else ever her of this?

I've had IDC (not DCIS) twice and am wondering about being exposed to radiation in the 1950s. I was a flight attendant living in Las Vegas and at that time they were doing testing just north of there in a town called Mercury. 

Also I was hit very hard in my breast as a teenager. Took birth control pills for a couple of years only.

There was also a chemical plant just north of where I lived for almost 40 years. They were often getting fined by the EPA.

I think it is a combination of environment, stress, food additives, etc.

Cathy1968...is it possible, too, that the mastitis was the result of structural changes in your breast that were the result of dcis?  In other words, the cause and effect might have been just the reverse...your mastitis might have resulted from dcis (or the adh that it might have been then).  Just a thought...

It is so easy to think of cause and effect within our own lives...but it is so important to look at large numbers of people before you draw conclusions.  There are just too many variables that you cannot control for in one life...

For me, I cannot consider the cause of my dcis.  I can only consider the care I want to take of me in the here and now...not just focused on bc, but on overall health.  There is no real way to know what caused it...and I may hate the answer anyway...I may not be able to live with the actual answer...there would be too many days of "what if..." 

CLC - Thank you, I totally get what you're saying...I actually said more or less the same thing I think at the end of my original post, that "maybe the reverse is true and the DCIS was already there and interfering with that duct's ability to fend off infection" i.e. resulting in mastitis...I believe you said it more clearly though - thanks! 

This thread is another example of what a "balancing act" this whole DCIS journey is:  on the one hand we know that we may never find out exactly why we got it but yet we did and just have to accept it; and on the other hand discussions about possibe causes, no matter how unusual may one day spark further research and provide more answers for future generations.

Edited to add:  a year prior to my dx I had a root canal...but on the other side!