Hi Leanne,
Firstly, while chemotherapy is a pretty unpleasant process, with support and medication to manage the worst side effects, it is not nearly as bad as it used to be. I can tell you from personal experience that most side effects fade away and that if it greatly increases your chances of surviving a lot longer or indeed being cured of cancer, it seems to me to have been a really worthwhile thing to put myself through.
Secondly, there are tests you can have done after surgery, once they know if your cancer is oestrogen-receptive, that can say whether you personally would be better having chemo or not, and some of them even test this out with your own cancer cells and the proposed treatment to see how well your cancer will respond to the treatment.
Did your doctor explain why he/she recommends chemo and/or radiation treatment after your surgery? Chemo is to mop up the cancer cells in theblood or lymphe that all of us with cancer can have anywhere around our bodies , and the radiotherapy is to mop up the cancer cells that can get left behind in the immediate vicinity of the original cancer site. Your cancer size is relatively large, so that would make it more likely to have spread even if not big enough to show up on scans. You need your doctor to tell you what are the risks of distant or local recurrence within 5 years if you do have Chemo/radiotherapy, and what are the risks if you don't. Then you can see whether it is worth it or not. For me, without it I had a 45% chance ( 1 in 2 ) of recurrence. With it, I have about an 8% chance(1 in 12). To me this is well worth while. If it only made about a 2% difference, I might not have bothered.
Unfortunately most types of breast cancers can metastasize, ie spread through the blood or lymph into other sorts of tissue using stemcell-like cancer cells. They find a suitable spot to grow, often in the liver, lungs, bone brain etc, and then start to form a new tumour or tumors. This can be immediately or it can be years and years later. This can happen even if your lymph nodes have no cancer in them. Chemotherapy goes all over your body and "mops up" these metastatic "seed" cells or small tumors, to help remove all remaining breast cancer cells wherever they are in your body.
Also, the tests we have done on us before surgery, ie bone test and body scan, only pick up metastatic cancers over 1cm in size. So there can be smaller cancers that have started even if the scans come back clear. Again, the chemotherapy mops these up.
Unless you had a big biopsy taken, much of the important information about your breast cancer tumor will not be available until a week or two after the tumor is out and the pathologists have checked out your sentinel lymph node and the tumor itself in very close microscopic detail. Then they will be able to say whether you will need to have targetted therapy for HER2+ type cancer, or Tamaxifen or Aromase Inhibitors for hormonally-receptive cancer. Then they should be able to tell you the risk with or without the treatments they recommend, and what there is about your cancer that makes these particular treatments right for you.
Best wishes for your surgery, and I do hope you can get the full details from the surgeon about why you need these treatments, and are able to make the choice that really will best help you live a good quality longer life.
