Clinical trials of adjuvant chemotherapy for breast cancer have shown
a prolonged disease-free interval but no improvement in survival. This
review of the evidence indicates that adjuvant therapy induces an ant
ineoplastic drug resistance that makes ''salvage'' therapy less effect
ive. The benefit that is seen only in group statistics, not in an indi
vidual, must be weighed against the harm an individual incurs from the
chemotherapy.