What breastcancer.org says....about bc patients face leukemia risk

[Jean]

Older breast cancer patients face leukemia risk

Chemotherapy affects normal, healthy cells as well as breast cancer cells. This is why chemotherapy can cause hair loss, anemia, and diarrhea. In rare cases, exposing normal cells to cancer treatments such as chemotherapy and radiation therapy can cause a new, different type of cancer to develop many years after treatment.
The large study reviewed here found that women who received chemotherapy for breast cancer were more likely to develop a specific type of leukemia called acute myeloid leukemia (AML) within 10 years of treatment than women who didn't get chemo for breast cancer.
It's VERY IMPORTANT to know that while the risk for AML was higher for women who got chemotherapy, the risk of AML is still very small. Women who got chemotherapy for breast cancer had a 1.8% risk of developing AML within 10 years of treatment. Women who didn't get chemotherapy had a 1.2% risk.

I think it is safe to say that while any medication can cause other health issues or severe side effects it is important to understand the risks with or without treatment. There is risk in just breathing the air or crossing the street. While no one wishes to increase their risk of any disease - when faced with a dx. of bc one has to consider all the risks and how high are the percentages.