Study of chromosome damage in patients with breast cancer treated by two antineoplastic treatments.

The frequencies of chromosomal aberrations (CAs) and sister chromatid exchanges (SCEs) were determined in peripheral blood lymphocyte cultures from women with breast cancer treated by chemotherapy (CT) with FEC (5-fluorouracil, epirubicin, and cyclophosphamide) or CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) cocktail in six CT cycles. The number of patients in each CT cycle were from 1 to 3 for SCE and 2 to 5 for CA. Samples were collected before and 48 h after CT. Although the size of the sample was limited and interindividual variability was wide, it appears that a 21-day interval between CT sessions is sufficient for cell recovery. This fact was demonstrated by the reduction in CA and SCE frequencies between cycles in parallel with the unchanged mitotic index and proliferative index values.