When & why is radiotherapy indicated for DCIS?

Hi all

I’ve been told - post wle - the dcis   was 17mm (previously thought to be 7mm) intermediate grade & margins clear . As ER+ve ive been advised to take tamoxifen but don’t need radiotherapy. 

My question is how it’s decided if radiotherapy is needed? I’ve seen on some other sites that some people with intermediate dcis, similar size ‘lump’ do have radiotherapy,  and some don’t.  Is it just a case of ‘trust the doctor’,  or do different Trusts have different practices or some other criteria? Thanks

Hi Suzecab,

 I had my first appointment with my oncologist today after having WLE, therapeutic mammoplasty and SNB seven weeks ago. He told me that radiotherapy is recommended for me because in my first biopsy a very small area, 2mm, of invasive ductal carcinoma was found along with 23mm of high grade DCIS. At surgery only a 28mm area of intermediate and high grade DCIS was found at the original biopsy site, margins and lymph nodes were clear. It seems all the invasive cancer was removed by the vacuum assisted biopsy. But because triple negative invasive cancer had been present radiotherapy is recommended to give the best chance of avoiding recurrence. If there had only been DCIS found in both biopsy and surgery and it had hormone positive receptors then he thought surgery and hormone therapy only would have been necessary.

So to put it more briefly I have to have radiotherapy because a tiny amount of triple negative IDC was briefly there in addition to the DCIS which means there is a stronger possibility of recurrence without radiotherapy and of course hormone therapy would be of no use. So it seems my NHS trust operates with same criteria as yours. I was told by my surgeon at diagnosis that they would not over treat me and this certainly seems to be the case. I have have heard of others with a similar diagnosis to mine who have been given chemo and ‘the works’ because of the discovery of the dreaded triple negative.

Sorry for such a long answer, I am sure I could have put it much more succinctly. I never did have a problem with reaching the minimum word count for uni assignments, always had to spend hours cutting out all the drivel to make them shorter .