how dcis becomes invasive

Thank you for the article.  Interesting and informative!  That's why we need each other--to keep information like this coming!

Bump

My oncologist said that DCIS must mutate to learn how to survive outside the duct. He said it has nothing to do with size of tumour. My tumours were grade 3, comedo necrosis and he said in all likelyhood, my tumours were well on their way to mutating and becoming invasive. He said someone with an 8 cm, grade 1, may never become invasive yet someone with grade 3 and <1 cm is a good indication it would become invasive. I had 8 tumours and even though they were aggressive and spreading rapidly within the duct, I was very fortunate they did not become invasive. I had a lumpectomy with a 1.5 mm margin. Tumour Board recommended a mastectomy. I agreed. Yet no additional cancer was found during the mastectomy; the lumpectomy got it all. People often ask me if I'm upset. NOT AT ALL!! How could "no additional cancer found" be anything but good news. Maybe if I was younger, I may have been upset. But as my husband says "whatever we need to do to keep you around for a very long time, we do." I have not regretted my decision to have a mastectomy. Sure, it would be nice not to have to go through reconstruction but I'd rather be going through reconstruction than find out too late that I really did have cancer outside of the lumpectomy area.

I am finding this discussion very interesting. I had a mastectomy for DCIS (multicentric, grades 2 & 3) just over 2 years ago and I still have so many questions.  I was told that the cells in my ducts would be extremely nasty and aggressive if they broke through the duct walls. DCIS was not mentioned on the day I was diagnosed. I was told that it was ok to wait a few weeks without surgery but certainly not months. I don't understand why some DCIS is picked up when it is only a few mm in diameter while other types (like mine) are not picked up until it has spread right through the breast and medium and high grade. Surely it should have been seen 12 months earlier...? Perhaps, due to my being premenopausal, my breasts were denser then and the microcalcs couldn't be seen? Although I don't recall being told that I had dense breasts.

I don't lose any sleep over this but at times I do wonder if there is something brewing in my remaining breast that still cannot be seen.

Sweatyspice, what do you mean when you say dcis component? Isn't it consider a component when the dcis eats through the ducts? What makes it a component?

geebung...I'm in my 60's and I have very dense breast to the point the technicians say its like trying to look through a wall. I think dcis can only be picked up when they see calcifications. Only the biopsy can tell for sure if there is an invasive component, or if its dcis. All high grade dcis is nasty and aggressive.  

Many women have more than one type of cancer (often DCIS and IDC) and the different types are called components.  For example, one person may have DCIS with an invasive component and someone else may have invasive ductal carcinoma with extensive intraductal component.  The first would have mostly DCIS but also some part of the tumor that is invasive.  The second would have IDC but also a noticeable amount of DCIS.  In either case IDC trumps the DCIS in staging because it is more serious but the DCIS may make it more difficult to surgically remove all of the cancer with clear margins. 

As cells change from normal to cancer they undergo several changes.  One change makes the cells proliferate uncontrollably.  Another change makes the cells invade other structures.  DCIS cells have undergone the first change but not the second.  IDC cells have undergone both changes. As long as the cells are DCIS they spread throughout the milk ducts and may become widespread but they do not invade.  If they happen to fall out of the duct through an opening or tear that does not make them invasive.  To invade the wall of the ducts or other structures the cells themselves have to change and become invasive. 

If the tumor remains DCIS for a while it may become large but still be all DCIS.  If the tumor starts as DCIS but quickly changes to invasive then it may be all IDC but be pretty much contained and small. 

Ductal tumors usually go along the spectrum from normal cells to hyperplasia to DCIS to IDC but the speed of changes in the cells varies and that affects whether the result when the tumor is diagnosed shows any or much of the earlier stages such as DCIS or hyperplasia.