Neoadyavant chemotherapy and postoperative irradiation in breast cancer: interrelation and prospects

In 2005 the Oxford meta-analysis of individual patient data from many trials showed no benefit to postmastectomy radiotherapy in node-negative breast cancer patients but reduced 5-year local recurrence and 15-year breast cancer mortality in patients with node-positive disease who underwent axillary lymphnode dissection. Despite these data, there is still some debate over the appropriateness of postmastectomy radiotherapy in patients with 1 to 3 involved lymph nodes. Neoadjuvant chemotherapy leads to clinical and pathological response in a certain proportion of patients. So far, the universal approach was to ignore the information on response to chemotherapy and recommend postmastectomy radiotherapy based on pre-chemo clinical disease status. The main goal of this article is first to summarize the evidence for the use of postmastectomy radiotherapy in a more traditional treatment sequence, and then show new evidence that highlights how information about the response to chemotherapy can be incorporated into the decision regarding the need and benefit of postmastectomy radiotherapy in the context of neoadjuvant chemotherapy.