Adjuvant chemotherapy for tumors of one centimeter or less: the law of diminishing returns.

The role of adjuvant chemotherapy in treatment of breast cancers of 1 cm or less is controversial. Careful consideration must be given to the overall risk of recurrence and death and to the absolute benefit of adjuvant chemotherapy, given that risk. Studies in this group of patients indicate that their overall survival rate is 90% to 99%. The absolute benefit of chemotherapy in this setting is most likely 1% or less. Adjuvant chemotherapy has significant toxicities, including cognitive dysfunction, early menopause, leukemia, and even death. Following a realistic and detailed discussion between patient and oncologist, some patients may choose chemotherapy. However, for the majority of patients with breast cancers of 1 cm or less, the minimal benefit of adjuvant chemotherapy does not justify the risk of the treatment.