Is chemotherapy alone adequate for young women with oestrogen-receptor-positive breast cancer?

Background The prognosis of breast cancer in very young women is generally considered to be unfavourable. Therefore, the outcome of adjuvant therapy w as analysed in a population of young (<35 years) premenopausal patients tre ated in four randomised controlled trials. Methods Between 1978 and 1993 the International Breast Cancer Study Group ( IBCSG) treated 3700 premenopausal and perimenopausal patients with various timing and duration of adjuvant cyclophosphamide, methotrexate, and fluorou racil (CMF with or without low-dose prednisone and oophorectomy). 314 of th ese women were less than 35 years old at randomisation. Findings Relapse and death occurred earlier and more often in younger (<35 years) than in older (greater than or equal to 35) patients with a 10-year disease-free survival of 35% (SE 3) versus 47% (1) (hazard ratio 1.41 [95% CI 1.22-1.62], p<0.001) and overall survival of 49% (3) versus 62% (1) (1.5 0 [1.28-1.77], p<0.001). Younger patients with oestrogen-receptor positive tumours had a significantly worse disease-free survival than younger patien ts with oestrogen-receptor negative tumours. By contrast, among older patie nts the disease-free survival was similar irrespective of oestrogen-recepto r status. Interpretation Young premenopausal breast cancer patients treated with adju vant CMF chemotherapy had higher risk of relapse and death than older preme nopausal patients, especially if their tumours expressed oestrogen receptor s. The endocrine effects of chemotherapy alone are insufficient for the you nger age group and these patients should strongly consider additional endoc rine therapies (tamoxifen or ovarian ablation) if their tumours express oes trogen receptors.