Selected patients of female gender, above 50 y.o, and after a biopsy of Luminal-like Breast Cancer will go under aromatase inhibitor, from the diagnosis day till the surgical therapy to be decided (if so).In this study are going to be included patients that refuse surgical treatment, remaining this way in an "active surveillance". This last group is going to be randomised in order to recieve hormontherapy plus placebo vs hormontherapy plus acetolisalicilic acid.