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Jul 9, 2009 05:23PM
Wow, this thread is confusing! Since I've spent close to 4 years reading everything I can find about DCIS, let me try to clear up some of the confusion and ease some of the fears.
Claudia, if I understand correctly, your question was about the risk of recurrence after having a mastectomy for DCIS. The answer is quite clear. Most studies - and I've read dozens of them - put the recurrence risk at about 1% - 2%. One or two studies state the risk to be higher (5% up to even 10%) but the overwhelming consensus of all the studies puts the risk at 1% - 2%. What this means is that of every 100 women diagnosed with DCIS who has a mastectomy, 1 to 2 of these women will have a recurrence. KrisseyKatz is one of those women. The reason that a recurrence is possible after a mastectomy for DCIS is because even with a mastectomy, a tiny amount of breast tissue will always be left - maybe just a few cells - but that breast tissue will be there and that's why there is a risk.
When DCIS recurs, there is approx. a 50% - 60% chance that it will recur as DCIS and a 40% - 50% chance that it will recur as invasive cancer. Pure DCIS cannot recur as mets, as least not without one step in-between. The step in-between is that first the DCIS would have to recur as invasive cancer. It could happen that if DCIS recurs as invasive cancer and this recurrence isn't found until it has progressed to become mets, it might appear that DCIS has recurred as mets, but in fact this isn't true - there was that step in-between. For someone who had a mastectomy for DCIS, the likelihood of the DCIS recurring as IDC and then progressing to mets is extremely small. For all women who have DCIS, including the approx. 60% who have lumpectomies (who generally have a higher recurrence risk), the risk of having an invasive recurrence that then progresses to mets is only 1% - 2%. What this means is that the long-term survival rate for DCIS is 98% - 99%. So for the 40% of DCIS women who have mastectomies, the risk would be significantly lower than 1%.
DCIS, because it is non-invasive, cannot recur in the other breast. Of course, anyone diagnosed with BC one time is at higher risk to get BC again, and this includes those who were diagnosed with DCIS. So someone could be diagnosed with a new occurrence of BC in the other breast but this would be a new cancer, not a recurrence of the original DCIS.
DCIS is Stage 0, non-invasive breast cancer. Anyone diagnosed as being Stage I, Stage II or Stage III does not have DCIS. Because so many women have DCIS along with their invasive cancer (DCIS and IDC are often found together), this can be confusing because the term "DCIS" is included in the pathology report. But any staging other than Stage 0 means that there is invasive cancer present. And what happens then is that the invasive cancer "trumps" the DCIS and the diagnosis and treatment is based on the invasive cancer, not the DCIS. In these cases, the DCIS in effect becomes irrelevant, except that it needs to be removed. So there is no such thing as DCIS Stage I or DCIS Stage II or DCIS Stage III. There is only DCIS Stage 0.
Similarly, because DCIS by definition is confined to the breast and cannot travel outside of the breast, and because chemo is given to address the risk that cancer cells have escaped the breast and moved into the body, chemo should never be required for DCIS. So it's pretty safe to say that anyone who is given chemo does not have DCIS (although there may be a DCIS component to their cancer, along with the invasive component).
Breast cancer is very complicated. It's not one disease; it's many diseases. And even one tiny difference in pathology can make a significant difference in the diagnosis or treatment. While DCIS is very commonly found together with invasive cancer, pure DCIS is distinct in it's treatment and prognosis. Claudia and Sue, I hope that this clears up some of the confusion and reassures you, at least a bit!
Dx 9/15/05, DCIS-MI, 6cm+ Gr3 DCIS w/IDC microinvasion, Stage IA, 0/3 nodes, ER+/PR- “No power so effectually robs the mind of all its powers of acting and reasoning as fear.” Edmund Burke