How to improve timing and duration of adjuvant chemotherapy

The efficacy of adjuvant systemic therapy for early breast cancer depends o n tumour, patient, and treatment-related features. Selection of treatment i s based upon tumour characteristics such as oestrogen receptor (ER) and pro gesterone receptor (PgR) status, and patient characteristics such as age an d menopausal status. Three retrospective analyses of the International Brea st Cancer Study Group (IBCSG) database were performed to assess the influen ce of tumour-related features and patient characteristics on timing of adju vant chemotherapy, on the efficacy of a short perioperative course of chemo therapy, and on the shorter rather than longer duration of chemotherapy. Timing: Early initiation (between 1 and 3 weeks from surgery) of adjuvant c hemotherapy improved disease-free survival in patients whose tumours did no t express ER. compared with typical timing to start of chemotherapy (betwee n 4 and 6 weeks after surgery). Outcome was not related to start of chemoth erapy for those patients whose tumours expressed ER. This analysis was cond ucted in premenopausal patients with node-positive disease. Perioperative therapy: A single course of adjuvant perioperative chemothera py (PeCT) was particularly effective for postmenopausal patients with node- negative ER and PgR-negative breast cancer. Indeed the absence of expressio n of ER, PgR or both was the most important factor predicting improved outc ome with PeCT among postmenopausal patients. No significant effect of PeCT was observed for premenopausal patients with similar characteristics of dis ease presentation. Duration of chemotherapy: Three courses of adjuvant chemotherapy with cyclo phosphamide, methotrexate, and 5-fluorouracil (CMF) were as effective as si x courses for an older cohort of premenopausal patients (age > 40 years), w hile younger patients (< 40 years old), or those at any age. but with tumou rs classified as ER-negative, six courses of the CMF appeared superior to t hree courses of the same regimen. Thus, information on endocrine responsive ness and menopausal status is important for focusing on best choice of timi ng and duration of adjuvant chemotherapy. (C) 2001 Harcourt Publishers Ltd.