In my case it was based on my OncoDx test. My score was 24 which left me in a grey area regarding chemo. If you have a low score, you may not need chemo. Radiation was a given because it helps prevent cancer from recurring in the same breast. Because my tumor had broken through the walls of the ducts that meant cancer cells were probably in my bloodstream & were carried throughout my body. I opted to have chemo to try to kill those cells and to decrease my chances of cancer spreading to other parts of my body. I am taking Arimidex for 5 years because my tumor was estrogen positive.

I was diagnosed 15.5 years ago with stage 1 b.c. Because my cancer was HER-2-positive (plus ER-positive and PR-positive), my oncologist mandated that I have four chemo treatments (Adriamycin and Cyotoxin), with radiation following).

I didn't have chemo because my oncotype dx score was low. I had radiation because I had one small tumor in one lymph node. If I was pre-menopausal I would have qualified for the oncotype dx test because of the tumor in the lymph node and would have had chemo.

There are always general guidelines for treatments, but honestly every single case of cancer is entirely unique and special! In other words, the oncologist has to tailor the treatment plan for each individual patient, so ask yours to explain all his or her reasoning and what they think is best to save your life and defeat the cancers as much as possible.
The problem is that they can’t see every single cell in our bodies yet, so cancer cells often lurk in the background somewhere and hide from us. Which is the reasoning for the chemo and radiation, to kill off any stray cells that don’t show on scans or in blood work. Because even one stray cell can divide and divide and divide and all of a sudden become an unmanageable cancer. :-(
But roughly the less tissue removed for an early stage caught breast cancer, the more chemo and/or radiation done after surgery. The more tissue removed, the less chemo/rad.
Well I admit that is very vague and very general......
And please keep in mind that now is the best chance you have of getting rid of this thing for good, so it is better to hit it hard now and fast as well. Diet, exercise, and sleep are all very important of course.
Good luck to you and God bless!

I'm stage IIb. My onc recommended chemo because I had 2 out of 5 positive lymph nodes in the sentinel biopsy - he always recommends chemo before radiation in this case, just to mop up.

There do seem to be standards, but onc have their own opinions as well. I am treated at a large university hospital. They seem to err on the side of caution and recommend the most aggressive treatment. I think it's because it's easier to treat initial cancer, than cancer that has mets.

I had a Stage 1 Grade 3 HER2+ invasive ductile carcinoma. That means it was very small, but very fast growing. I had a lumpectomy with no lymph node involvement but many tiny capillaries in the area of the cancer. That meant there was still a chance that a few cells might have gotten into my bloodstream. My onc told me my chance of surviving 5 years as is, how much it went up with chemo and how much it went up with rads. My choice was to take every chance offered, to increase my chance of life even if only a few percent for radiation. All together it came out likely I would survive this interloper.

Like SandraK I had a Stage 1 Grade 3 HER2+ invasive ductile carcinoma. Small tumor but 7cm of DCIS requiring 2 lumpectomys My oncologist insisted on 6 courses of TCH with Herceptin every 3 weeks for a year plus radiation. HERS2 is an agressive tumor and merits throwing everything you have at it so it doesn't come back

I only had radiation after my lumpectomy. I was stage 1a IDC. My understanding from the Doctors, was that because my nodes were negative, I did not need Chemo.

MollyAWelsh, my nodes were negative, too - that's part of having a stage 1 tumor, in addition to the size being 2cm or smaller - but I had to have four chemo treatments (A/C but nobTaxol), because my cancer was HER-2-positive and thus aggressive. This was 15 years ago, and protocols may have changed.

I had 4 TC chemo infusions prior to surgery and 2 after; then I had 33 radiation sessions. My oncologist ran me through aggressive treatment because of my age and the fact that one node showed activity the day of surgery. Every patient is different, so you will have to talk to your oncologist to see how your treatment plan is to unfold. HUGS and God bless!

I too was "only" Stage 1, but needed to do chemo and radiation because I was triple negative.

Thank you all so much for your responses to my inquiry regarding treatment following lumpectomy. Things are clearer now and I'll just have to wait out the next two weeks until I find out the results of my testing.

that OncoDx test has really changed a lot of chemo treatments. It used to be given to just about everyone, as a just in case. My OncoDx number was 14 and the onc said that chemo would increase my 'livability' by 1% so it was not recommended.
http://www.oncotypedx.com

I was stage IIB IDC with a 2.4 cm tumor that took 3 surgeries to barely get clean margins (just 1mm). Also had 2 positive nodes. This made my oncologist recommend both chemo and radiation even though my oncotype score was very low (8). Score reflects recurrence chances. But my doctor and I wanted to get rid of as many of the stray cancer cells as possible first.

My understanding is that you need to pair lumpectomy with radiation since the stats for lumpectomy + radiation are the same for mastectomy.
Chemo is added if there is spread to the lymph nodes or it is very aggressive.