effect of chemotherapy in breast cancer

Women aged younger than 35 years have a particularly high risk of recurrence and should strongly consider treatment with chemotherapy.117

Clinicians should advise younger women that the benefit of chemotherapy is greater the younger the woman’s age. Chemotherapy will reduce the risk of recurrence by about one-fifth in women aged 60 to 69 years, but by nearly two-fifths in women under the age of 40.


The risk of recurrence never completely goes away. Clinical trials show that women aged younger than 50 years who had chemotherapy have lower rates of recurrence than those who did not, even 10 years after treatment.115 While a younger woman has a potentially long time at risk of recurrence, she also has a long time to accrue the benefit of adjuvant chemotherapy. The risk of recurrence depends on a number of factors, but an average effect of chemotherapy in women less than 50 years old would be to improve 10-year disease-free survival from 80% to 87% (small node negative tumour) or from 55% to 70% (small node positive tumour).118