chemo when sentinel node negative

I had a lumpectomy on May 22nd, with a sentinel node biopsy.  Only one node was found, and it was negative on frozen section, so no further nodes were taken,  My diagnosis was IDC, with tubule formation 2, nuclear grade 3, mitosis 1 and the tumour size was 7mm x 7mm x 6mm.  Frozen sections seem to indicate that clear margins were achieved.  I will get full pathology rsults back this coming Friday the 30th.  If those results agree with the frozen section results, I'll be looking at treatment options. (If not, there will likley be a re-excision.)  I know that radiation will be required, but I wonder what the indicators are for chemo given my circumstances.  (I do not yet have hormone receptor results yet either.)  I am 60 years old, post menopausal and otherwise in excellent health.  Please advise.  Thank you.
Marie

[Cleveland Clinic]

Dear Marie, Decisions about adjuvant chemotherapy or hormonal (antiestrogen) treatment are based on several factors including size of tumor, status of lymph nodes, the appearance of the cancer under the microscope, the presence or absence of hormone receptors for estrogen and/or progesterone, as well as HER2 status, the general health of the patient etc.  We can not make specific treatment recommendations for an individual in this forum. We can tell you that antiestrogen treatments are frequently given following surgery for ER/PR-positive breast cancer to reduce the risk of recurrence in the form of metastatic disease. Chemotherapy may add an additional benefit that needs to be weighed against the potential side effects. Her 2 positive tumors generally increase risk to intermediate or high risk which would increase the likelihood of adjuvant chemotherapy being recommended.  Your oncologist will be better able to discuss these options with you once the final pathology results are available.