In 1998 the Early Breast Cancer Trialists’ Collaborative Group published
an overview of randomized adjuvant trials for the treatment of early breast
cancer.4 Their analysis involved approximately 30,000 patients
in 69 clinical trials. These included 47 trials of prolonged combination
chemotherapy versus no chemotherapy, 11 trials of short versus prolonged
use of combination chemotherapy, and 11 trials of anthracycline-containing
regimens versus CMF (cyclophosphamide, methotrexate, and fluorouracil).
The overview analysis revealed that combination chemotherapy produced
substantial and highly significant reductions in recurrence, both in women
under 50 years of age (35% reduction) and in women ages 50 to 69 (20% reduction);
few women ³ 70 years of age had been studied. Significant reductions
in mortality were also observed for these age groups, 27% and 11%, respectively.
After standardization for age and time since randomization, the proportional
reductions in risk were similar for those patients with node-negative and
node-positive disease. The age-specific benefits of therapy also appeared
to be irrespective of menopausal status at presentation, estrogen-receptor
status of the primary tumor, and of whether adjuvant hormonal therapy had
been administered.4
The collaborative group also found that there appeared to be no survival
advantage associated with the use of combination chemotherapy for more
than 3 to 6 months. Regarding specific chemotherapy regimens, available
data from randomized studies suggested that anthracycline-based regimens
produced somewhat greater effects on both delaying recurrence and survival
than did CMF; however, the investigators stated that it could not be determined
based on available evidence whether these differences were meaningful.4
