METHODS	From July 1986 to April 1993 the International Breast Cancer Study Group ( IBCSG ) Trial VI randomly assigned 1554 pre/perimenopausal node-positive breast cancer patients to receive cyclophosphamide , methotrexate , and 5-fluorouracil ( CMF ) for either three consecutive courses on months 1-3 , or six consecutive courses on months 1-6 , both with or without reintroduction CMF .\