The benefits of adjuvant chemotherapy depend on the woman's age and the stage and type of breast cancer. As noted below a young woman with a very high risk cancer (large tumor size and multiple lymph node metastases) and only a 12.8% chance of surviving 10 years but by adding hormone therapy she improved her odds to 25% and by also adding chemotherapy to 53%. On the other hand an older woman with a small tumor and no lymph node spread improved her 10 year survival from 68.6years to  69.6 years by taking hormone and chemotherapy. To do the calculations go to adjuvant online.