Dear @PetraSminsk
If you and your mother have faith in your oncologist, be guided by him/her. Mine was very clear that in his opinion chemo was an important part of treatment. If he’d said it might make no difference, then I might not have had it. I had some side effects but no fatigue or nausea, kept working and as I wore a wig, most people had no idea about any of it (I was 68). As many people have pointed out, even the oncotype may leave the decision primarily up to the patient! My breast surgeon refused to advise on chemo (referring me to my oncologist) but said every percentage point counts. Like @AllyJay, that stuck with me. I’ve once been the ‘one in 10,000’ (nothing to do with bc and all happily fixed), and you really don’t want to be on that side of the percentages. Best wishes whatever you decide.