Chemotherapy needed for grade II and III cancer? Should we choose clinical trials?

Hi,
My 51 year old mother felt two nodules in her right breast about 3 months ago, so we did the biopsy, and followed up. Here are the biopsy results. Her 70 year old sister had malignant breast nodules two years ago, which were removed by surgery; however, she did not go under chemotherapy. No other family history of breast cancer.

Biopsy results:
"The pathology report of the 11 right breast lesion reveals infiltrating ductal carcinoma grade II to III manifesting no ductal carcinoma in situ nor lymphovascular invasion. The pathology report of the 12 o'clock breast lesion reveals benign skin and breast tissue showing focal fibrosis and chronic inflammation but no identifiable malignancy.
Impression:
1) infiltrating ductal carcinoma of right breast 11 o'clock lesion; bi/rads V classification
2) benign findings of 12 o'clock right breast biopsy; bi/rads II classification"

the malignant nodule was mentioned to be 1 cm in the ultrasound results (couldn't find it to write it down for you), but the surgeon who took the nodules out told my mother that during surgery, the nodule was 3 cm, which means might have grown. The oncologist has recommended one of the two options to my mother:
1) 5 years of estrogen block therapy + go under chemo for 4 months
2) there is a trial that they are gonna analyze the cancer cells, and if they see the recurrence score is more than 25, they will give her chemo. Now for those people who get the chemo, they get randomly assigned to 3  tirlas, one is injection of chemo, one is oral chemo, and one is another chemo drug that is usually given to other cancer patients. IF they find a chance of recurrence lower than 25, they will only do radiation and hormone therapy only.

Do grade II and III cancers without metastasis really need chemo ? Should we go with regular chemo or with the trials? Would really appreciate any addition doctors' remarks and recommendations. I am a dental student, so please don't hesitate to use scientific language.

[Cleveland Clinic]

Dear herogt350:  There is more to the decision to do chemotherapy than grade.  Other things include size, ER/PR status, Her 2 status, lymph node status, etc.  The trial that is being offered has eligibility criteria that your mother apparently meets and is trying to answer the question about who needs chemo and which chemo.  The other option the doctor offered is likely the standard of care that is offered outside the context of the study based on her particular cancer.  In other words, we are still learning who needs chemotherapy and who may not.