I agree with Oncrx that mastectomy SHOULD be an option, but your surgeon may feel that with your diabetes, it would not be a good option, and not just from the standpoint of breast conservation. In general, the more invasive the surgery, the more traumatic it is to the body, and the more difficult from which to recover. Diabetes complicates this further. Mastectomy will require more time under anesthesia than lumpectomy. It will also create more need for tissue healing, (and possibly more opportunity for infection.) The stress is greater on diabetics than non-diabetics. It's a delicate balance, trying to decide whether to take the road that offers the best results for the short - term, or to increase present risk in hopes of a better long-term outcome.
It is not uncommon to have only one appt with the oncologist before surgery. (Many people do not have their first visit with an oncologist until after surgery.) Until the cancer is removed, the area is looked at thoroughly to assess for invasion, and at least the preliminary pathology report has been received, the oncologist will not know for sure just what drugs to use and how much. This first visit is to give you a chance to learn what you might be facing, and to ask questions. The oncologist probably has an idea of what he/she would like to give in the way of treatment, and probably will discuss that with you, but until they know more definitely from the surgery more exact details about your situation, there probably really is no reason for more than just that one visit.
One question that you should ask when you do make that first visit to the oncologist: does he have experience dealing with diabetics, and what precautions will he take to keep you safe. (What is he going to do to guide you through the changes that chemo is going to bring about in regard to diet, insulin or other medications, etc.)
Consider trying to find a naturopathic/holistic practitioner to help you through the surgery, chemo and recovery; preferably someone who is willing to advise you on diet, naturals, and supplements as complementary therapy to help speed your recovery, control your diabetes, as well as to fight the cancer.
Also, I recommend that you start now to find a cancer support group in your area. Your surgeon and/or oncologist should be able to help with that. You might also talk to whomever treats your son for his schizophrenia - see what they can offer in the way of support groups, people in the community who have dealth with this type of situation before, therefore might have good advise and possibly be able to offer hands-on support as well. The American Cancer Society might be able to give you good contact information: http://americancancersociety.org/docroot/home/index.asp
I wish you the very best. Please let us know how you are doing after your surgery.
Sincerely,
Tre