Hello Ladies,
I'm sorry to hear about your experience, Sarah. I can understand your passion!
I haven't got the resources I would have at my work at the moment so I'm using the net and my memory here.
DCIS is present in two situations - pure DCIS and DCIS associated with invasive carcinoma. The latter is treated primarily according to the invasive component. I'm going to focus on "pure DCIS" for this post.
Sometimes a diagnosis of pure DCIS is made, but there is hidden or occult invasive carcinoma present. This can be straight misdiagnosis or a sampling problem by pathology. Note that you cannot process every bit of a lumpectomy (unless it's small) or mastectomy for pathology - representative samples are chosen to be examined. There is not enough money and there are not enough pathologists in the world for every bit to be sampled. Our laboratory in Austraia makes no money out of Breast surgical specimens, these complex tests are cross-subsidised by the small skin and gut biopsies we do.
If high grade DCIS is found, a sentinel node biopsy is often done in many centers, particularly if the DCIS is over a large area because of the risk of occult invasion and the possibility of a node met.
Even if there is diagnosis of pure DCIS is correct, invasive carcinoma can develop in remnant breast tissue or on the other side. This is because all the breast tissue has been subject to carcinogenic forces over the patient's life.
The 10 year survival of pure DCIS is 96-98% (98% in recent years) but the risk of recurrence of either further DCIS or invasive DCIS after an initial diagnosis of pure DCIS found on an excision specimen is quite high over time, varying from 1 to 3-4% per year. The higher figure is for high grade DCIS. A woman with DCIS is 3.9 x more likely to get invasive breast cancer than the average woman. One meta-analysis showed women <40 years at the time of diagnosis have an 89% increase in risk of ipsilateral breast tumor recurrence (IBTR) compared to women >40 years at diagnosis.
http://jncimono.oxfordjournals.org/content/2010/41/121
SO: pure DCIS needs to be excised if possible, especially if high grade, +/- sentinel node, radiation and/or tamoxifen. The benefit of systemic chemo hasn't been proven (the maximal possible benefit would be 2% at most because the survival is already good). There is no real place for neo-adjuvant therapy in pure DCIS as you can't diagnoses pure DCIS without excision anyway.
Below I include some links to suggest that a little anti HER2 therapy, given at the time of therapy may help reduce later recurrence of HER2 positive DCIS but the evidence is still not in.
Low grade DCIS is a different disease to high grade but usually has the same treatment, but I might write more about this another time.
CLOSE FOLLOW UP OF DCIS IS CLEARLY WARRANTED!
DCIS is also divided into grades (low, intermediate and high grade) and into subtypes on the basis of appearance and receptor/ HER2 status. About 50% of high grade DCIS is HER2 positive. HER2 positive DCIS is often seen in association with HER2 negative Invasive duct carcinoma as well as with HER2 positive invasive carcinoma. When HER2 status is reported, it is very important that it is the invasive component that is assessed.
Some interesting links:
2009 Seminar for patients about DCIS. Very discursive but covers many of the issues in an intelligent way
www.lbbc.org/content/download/1311/9974/file/LBBCdcis09.pdf
General info about DCIS on cancer network. You may have to get a member login
http://www.cancernetwork.com/cancer-...-breast-cancer
MDA Anderson Centre: Dr Kuerer discusses DCIS, including an indication that one dose of IV Herceptin in treatment of DCIS may be beneficial.
http://www2.mdanderson.org/depts/onc...0-compass.html
DCIS and Lapatinib - ongoing trial
http://www.clinicaltrials.gov/ct2/sh...ductal&rank=1]
That's all for now
Aussie Girl