Tumors with a high S-phase fraction tend to have an increased risk of recurrence. Although prognostic factors provide important information about the risk of recurrence, they do not enable doctors to predict exactly who will be cured by primary therapy and who may benefit from adjuvant therapy. This complicated decision-making process is best carried out by consulting an oncologist, a doctor who specializes in cancer treatment. Adjuvant therapy usually begins within 6 weeks after surgery, based on the results of clinical trials in which the therapy was started within that time period. Doctors do not know how effective adjuvant therapy is in reducing the chance of recurrence when treatment is started at a later time.
Chemotherapy is given by mouth or by injection into a blood vessel.
Either way, the drugs enter the bloodstream and travel throughout the body. Most patients receive treatment in an outpatient part of the hospital or at the doctor's office. Adjuvant chemotherapy usually lasts for 3 to 6 months. In adjuvant hormone therapy, tamoxifen is taken orally. Tamoxifen enters the bloodstream and travels throughout the body.