Is my surgeon undertreating?

Linda, 

Your signature line says that your DCIS was 1cm in size.  Was it a single focus of DCIS or was it multi-focal?  What was the actual pathology, i.e. was there any comedonecrosis present? And how large were the surgical margins?  

What determines your recurrence risk is the size of the tumor, the grade and presence of comedonecrosis, whether there is a single tumor or whether the tumor is multifocal, and most importantly of all, the size of the surgical margins.  Recurrence risk after a lumpectomy for DCIS can be as low as around 4% or as high as around 60% - it all depends on those factors.  So what additional treatments you may require after surgery depends on the specific pathology of your DCIS.  

As momof3boys suggested, you should see a medical oncologist.  A surgeon's area of expertise is surgery - not post-surgery treatment.  A radiation oncologist's area of expertise is radiation therapy - not other treatments.  The role of the medical oncologist is to look at the pathology, assess your risk and then discuss with you the pros and cons, and the benefits and risks, of each possible post-surgical treatment.   A MO is the person who can tell you if your current treatment path (surgery, intraoperative radiation only, no Tamox) is the appropriate treatment to get your recurrence risk down to a level that you can live with or if this might leave you with a recurrence risk that is higher than you would be comfortable with. 

Interesting that the RO is bringing up the idea now of addditional radiation. 

It is my understanding that the effectiveness of IORT (as well as other forms of partial breast radiation) is based on the data that shows the majority of re-occurances are in the same general area of the breast as the original occurance.  So if you had IORT to take care of that, why would you want additional radiation, unless they found something additional in your pathology that increased your risk to other parts of the breast.  Is it because the tumor size is a bit larger than expected?

I had a lumpectmy and partial breast radiation.  My tumor was very small (.3 cm) and had great margins.  But my BS wanted me to take Tamox.  I declined because according to my RO my reoccurance risk is around 5%, so the side effect risk to me did not seem worth a couple of percentage point. 

You asked if your BS is undertreating?  For some people, maybe, but for me I would say no.    It could be argued that most other BS's error on the side of recommending overtreatment. But there is no question that tamox can reduce risk of reoccurance...lots of studies to back that up. I wish the doctors of this world would lay the data our for us patients a little more logically for us to make a choice, rather than just giving their recommendation and expecting that we will just agree.    for some people the piece of mind that comes with doing everything they can do reduce risk of reoccurance is worth the side effects of tamox (even if only a 2% improvement),  Others such as me think of it as overtreatment to take it and only get minimal improvement.