Breast Cancer Stem Cell Correlates as Predicative Factors for Radiation Therapy

In today's era of personalized medicine, the use of radiation therapy for breast cancer is still tailored to the type of surgery and the stage of the cancer. The future of breast radiation oncology would hopefully entail selecting patients for whom there is a clear benefit for the use of radiation therapy. To get to this point we need reliable predictors of radiation response. Cancer stem cells have been correlated to radiation resistance and outcome for patients with breast cancer, and there is considerable interest in whether cancer stem cell markers or biologic surrogates may be predictive of response to radiation therapy. We review the data or in some cases lack of data regarding stem cell correlates as predictors of radiation resistance as well as the correlation of known predictors with stem cell biology. More research is certainly needed to investigate potential predictors of radiation response, stem cell or otherwise, to move us toward the goal of personalized radiation therapy.