Confused about expected results

My girlfriend was had her surgery back in Jan. At that time they removed 3 small areas and then 2 weeks later went back in and removed another small area. She's been on chemo ever since every 2 weeks. She is very vauge when I ask about Dr's appointments. She says the Dr doesn't like the blood work, or I'm not good enough to take treatment this period. My question is, what is a Dr. looking for in blood work to tell him to stop the treatment.. by either is finished or she's too sick to have a treatment.

How long will this take before it's done?

[CCF-RN,MSN-JS]

Dear JS84T, Chemotherapy does not exclusively effect cancer cells it also effects faster growing cells in the body.  The blood cells in our bodies reproduce relatively quickly so when certain chemotherapies are given they can cause these blood cells to be lower, particularly the white blood cells that protect against infection, platelets that help to clot the blood and red blood cells that carry oxygen.  If these blood counts are low this can put a person at risk for infection, bleeding or anemia.  The difference between effecting normal blood cells and abnormal cancer cells is normal cells counts will recover after some time.  Chemotherapy cycles are timed (in this case every 2 weeks) so that the normal blood cells are recovering.  To make sure they are recovering to a level that we can safely give another dose of the chemotherapy, a blood count is checked - based on the results of the blood count it is determined that is safe to proceed with the next dose.

If this is adjuvant therapy (treatment is given after surgery to try to prevent or minimize the growth of microscopic deposits of tumor cells that might grow into a recurrent tumor) for breast cancer treatment is usually given over about 4 months.  This may be longer if there were delays because of side effects.