Clinical trials on adjuvant chemotherapy for breast cancer

Clinical trial initiated in 1975 at the Petrov Research Institute of Oncology (Leningrad) included 1228 patients with breast cancer Stages I, II, and III. Adjuvant chemotherapy in patients with Stages I-II (P T0-2N0-1M0) leads to decrease in mortality rate by 24.3% in the case of monochemotherapy (thiotepa, six courses, 200 mg each course) and 32.4% in the case of polychemotherapy (thiotepa, methotrexate, 5-fluorouracil [TMF], cyclophosphamide, methotrexate, 5-fluorouracil [CMF], six course). There is a trend to higher (by 7.8%-9.8% versus control) rates of adjusted survival in the groups of patients with relatively early stages of breast cancer (P T0-2N0M0) subjected to adjuvant mono- and polychemotherapy. In the group of breast cancer patients (P T0-2N0-1M0) who received adjuvant polychemotherapy (TMF, CMF schemes) the survival rates are higher by 12.0%-16.6% than in the control group during the sixth, seventh, and eighth years of the follow-up. Favorable effect of adjuvant chemotherapy manifested by diminished mortality rate and prolonged survival was statistically significant only in the group of patients younger than 50 years.