IBIS-II trial for DCIS - anyone out there on this trial?


Is there anyone out there on the IBIS - II trial for DCIS? The trial is designed to compare tamoxifen and anastrazole (Arimidex) in post menopausal women with DCIS. I am a suitable candidate, having been diagnosed with DCIS back in April and having had a WLE and 5 weeks of radiotherapy. I am actively investigating joining the trial, under which I would have a 50/50 chance of getting tamoxifen or Arimidex - but without knowing which drug I will be on (although it is apparently possible to guess fairly accurately which drug one is on because of the type of side effect experienced eg joint pain normally indicates Arimidex). The alternative is 5 years on tamoxifen. Arimidex isn’t prescribed for DCIS yet (that is what the trial is intended to investigate) - so the only way for me to have a chance of accessing Arimidex is via the trial.

I am having real difficulty evaluating the options - particularly the potential side effects. My consultant appears to be concerned about some of the longer term side effects of Arimidex on joint pain, bone loss and memory/concentration, so is steering me towards Tamoxifen. But reading through the entries in this section, both drugs seem to cause similar side effects and Arimidex may offer better protection from a recurrence in the context of invasive breast cancer. I saw some correspondence threads on this topic dating back to 2005 but nothing more recent - so I would be grateful to hear from anyone who is on the trial currently to hear how they are coping or anyone who thought about joining the trial but decided against it.


Hi there. I too am on this trial. Thought I might have the real drug as my nails absolutely disintegrated but am now not sure as I have not had joint pain. I am having 18 monthly mammograms and am coming up to my next one in October and am absolutely petrified that they will find something. Have poked and prodded so much that I am sore. Keep thinking I find something when I am standing or sitting but when I keep my finger on the spot and go and lie on the bed it is gone. The 18 monthly mammograms were the thing that clinched going on the trial for me as 18 months isn’t long between so if something is found it has probably not been there long. I have been on steroids for Polymylgia Rheumatica for 18 months now so any joint pains would probably not show anyway. I really hoped I was on the real thing but hey ho. I didn’t realise the trial was for DCIS - I thought it was just breast cancer as a whole - well you live and learn. I really think it is worth doing if only for the mammograms.

Crehensal (Jan)

Crehensal again. As I have not every been diagnosed with cancer (just a couple of benign conditions) I am either on the drug proper or a placebo.

Hi Crehensal

Thanks for your posting. It is all very confusing, but there are 2 IBIS II trials going on. The overall study is split into two parts:

  1. IBIS-2 DCIS
    IBIS-2 DCIS will investigate which breast cancer treatment drug, anastrozole or tamoxifen, is better at preventing the disease from returning in women who have had an early type of breast cancer called Ductal carcinoma in situ (DCIS).
  2. IBIS-2 Prevention
    IBIS-2 Prevention will see if a breast cancer treatment called anastrozole can help prevent breast cancer in women at high risk of the disease.

From your description, I believe you are on the Prevention Study while I am looking at the DCIS Study. I agree the regular mammograms are a very important feature, but I think I would be on annual mammograms whichever way - so for me it is still something of a toss up between the two drug options. But I hope all goes well for your next check up in October - it is all the uncertainty that is tough isn’t it?

You are correct it is the preventative one that I am on. Yes, the uncertainty is absolutely killing. I don’t know why I am getting myself into such a state as the breast cancer nurse on the telephone told me that my logical thinking (as and when that kicks in) is correct that 18 months down the line if there is anything there it’s likely to be small and highly treatable, but then my illogical side kicks in and panic again. There is no hope for me. I was absolutely OK until I got the appointment through.

Good luck