mastectomy for DCIS

sc2012

My mother had DCIS 13 years ago, followed by radiation and tamoxifen.  (She had also had an early breast cancer in the same breast in which she then had lumpectomy).

Now, this year, 13 years later, in the very same breast a biopsy has shown DCIS again, which was in the form of microcalcifications

The doctor is recommending mastecomy. 

Two questions please: What is the risk that the mastecomy procedure could find any invasive breast cancer?  If the biopsy indicates DCIS, how often does the mastecomy end up showing some invasive cancer?

Beesie

"If the biopsy indicates DCIS, how often does the mastectomy end up showing some invasive cancer?"

About 20% of the time.  The odds are higher if the DCIS found in the biopsy is high grade and particularly if there is comedonecrosis and/or if the area of DCIS seen on the mammo or MRI appears to be large and/or multi-focal.  That means the odds are lower if the DCIS is lower grade and if it appears that there is just a small, single focus of DCIS.  

While the presence of any amount of invasive cancer, even just 1mm (as I had) changes the staging from Stage 0 to Stage I, in about 15% of cases, the amount of invasive cancer that is found is small enough that it doesn't change the treatment plan and hardly changes the prognosis.  Only in about 5% of cases does the invasive cancer cause a more significant change in the treatment plan and prognosis. 

Good luck to your mother.  Hopefully the diagnosis turns out to be Stage 0, with DCIS only.

crystalphm

Beesie answered very well, as she always does. I don't have technical answers, but I wanted to share I needed to have a mastectomy for DCIS because it was multifocal (meaning in several places) so it was my safest option.

Ask the doctor why he suggests a mastectomy, he should give you a reasonable answer. For me, knowing I would lose my nipple and 3/4's of my breast plus radiation, or a mastectomy, it was the easiest thing to do.

For me personally, I need to live my life and not allow constant breast worries to take over....so my choice was made to have the mastectomy.

Wishing the best for your mom, she is lucky to have you!

moonie

Hi there.

I don't know anything about the stats of how often there is invasive BC and certainly everyone has to make their own personal decisions.

My "guess" is...if she already has had a lumpectomy on that breast, there might not be much left of it by the time they did another lumpectomy.  I would think the mastectomy with reconstruction if she wanted it, would be a better choice.....but just my opinion.

My story was that my DCIS was so widespread there would not be much left by the time they got good margins etc to get it all out---that may also be true for her?  In my case, it turned out to be a good thing I had the mastectomy as there was very small invasive bc that was not detected by mammogram, U/S or MRI.  I felt fortunate they found it early enough that I managed to avoid chemo. 

If she has already had this show up twice....it seems the cancer in that breast just will not back down---I wouldn't want to take a chance of it coming back again....

.....but again....just my opinions...

 Best of luck to her and the decisions made by the patient are ALWAYS the right ones, since none of us has a crystal ball.

sc2012

Thank you all very much. 

sc2012

Beesie:

 I'm very sorry, but I read your reply over again and I just want to be certain

I understand fully what you're saying.  Even, if God forbid, they do find

some invasive cancer with the mastcecomy for my Mom, they would only increase the stage from 0 to 1?  Correct?  And

that only in 5 percent of cases would it significantly alter the prognosis?

I don't know what the stage of the DCIS is, but the doctor before the biopsy had

indicated it was small.

 Thank you very much.

Beesie

DCIS is always Stage 0.  It doesn't matter how much DCIS you have, or the grade of the DCIS, it's always Stage 0.

However, if some invasive cancer is found, the Stage depends on the amount of invasive cancer that is found and whether or not there is nodal involvement.  Just the presence of a tiny amount of invasive cancer immediately changes the staging to Stage I but if there is more invasive cancer, or if the nodes are affected, the diagnosis could be Stage II or Stage III.  If distant metastisis is discovered, the diagnosis would be Stage IV.

Anything is possible.  However in about 80% of cases where DCIS is discovered in a biopsy, the final diagnosis remains Stage 0, with pure DCIS.  In the other 20% of cases, most (15% of the 20%) only involve a small amount of invasive cancer, making the diagnosis Stage I.  In about 5% of cases, the amount of invasive cancer found is larger, and/or there is nodal involvement.  Then the Stage might be higher and the treatment plan might change significantly.  

If your mother appears to have only a small area of DCIS, then her odds of having anything more than DCIS are probably smaller than the 20% average.  It's those who have a large area of DCIS who have the greatest risk that something more might be found. 

sc2012

Beesie -- Thank you very much again for your thoughtful answers.