 The BOLERO-2 study demonstrated an enormous benefit for patients who received everolimus in addition to exemestane in patients who progressed duringafter a non steroidal NSAI, which led to approval of everolimus in this indication. However, experience from routine use report a high rate of intolerability of this innovative treatment approach especially during the first 12 weeks of treatment. Most common side effect is mucositisMucositis which is considered the leading cause for treatment discontinuation not related to tumor progression. 