Just diagnosed and terrified

You most likely won't get the staging information.

If you have chemo before surgery, then you will be provided with a Clinical Stage, which is determined based on the biopsy results and imaging. I would expect that additional imaging would be done (MRI, maybe a CT scan) before Clinical Stage is determined so you wouldn't get that today.

If you are having surgery first, then you might get an estimated stage (but probably not) and instead will get your Pathological Stage after surgery. This staging is based on what's actually found during the surgery, as well as anything else that might be evident from imaging.

Pathological Stage is the most accurate for those who have surgery first, but for those who have chemo prior to surgery, because the chemo will hopefully reduce the size of the cancer in the breast and the nodes (if there is cancer in the nodes), pathological stage become pretty meaningless. This is why Clinical Stage is provided to these patients, even though it may not be 100% accurate.

Good luck with your appointment today. You should come out of it knowing the ER status, PR status, HER2 status, grade, and recommended surgery plan.

Positive or Negative is what you will probably get for the ER, PR and HER2. You may get percents, but sometimes you do and sometimes you don't. The percents might be in the pathology report (but again might not be).

ER+ patients (and better yet, ER+/PR+) receive endocrine therapy - anti-estrogen therapy. In some cases these treatments are sufficient and chemo isn't required. These treatments are not helpful / available to patients who have ER-/PR- cancers, which means that patients who have ER-/PR- cancers are more likely to require chemo even for smaller tumors.

HER2+ cancers are very aggressive, and patients with even very small tumors will get chemo and Herceptin (a drug targeted at HER2+ cancers). The good news is that these treatments are very effective, bringing the risk for these patients down to levels comparable to much less aggressive cancers.

This information is crucial to the development of the treatment plan, so I'd guess that your mother's information was probably in the pathology report but maybe she never asked for a copy.