The impact of tumor stroma on drug response in breast cancer.

In the last two decades the breast cancer mortality rate has steadily declined, in part, due to the availability of better treatment options. However, drug resistance still remains a major challenge. Resistance can be an inherent feature of breast cancer cells, but can also arise from the tumor microenvironment. This review aims to focus on the modulatory effect of the tumor microenvironment on the differing response of breast cancer subtypes to targeted drugs and chemotherapy.