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Abstract:
The results of analyses of randomized clinical trials of adjuvant (postoperative) treatment of early breast cancers (T1-2N0) still remain inconclusive as to which category of sufferers it is indicated for which modality and, whether it should be used at all when prognosis is favorable and surgery alone is likely to assure long-term recurrence-free survival. The randomized trials of adjuvant treatment of breast tumors conducted at the Prof. N.N. Petrov Research Institute of Oncology started in 1985 involved over 2,000 patients, with 10-year follow-up (85 months on average) in 539 cases. To conform with randomization requirements, patients aged 55 and younger were divided into 4 groups: I-no adjuvant treatment (control); II-chemotherapy (CMF modality); III-tamoxifen (Tam) and IV-combined therapy with CMF and Tam. The rates of overall survival were: group 1-76.3; group II-89.7; group III-84.2 and group IV-84.9%, respectively. Recurrence-free survival: group I-68.4; group II-83.3; group III-77.6 and group IV-75.3%, respectively. The differences from controls were not significant (p > 0.05), except in group II. Patients older than 55 years (postmenopause > 5 yrs) were divided into 3 groups: I-control (no adjuvant treatment); II-tamoxifen and III-diethylstilbestrol. Overall survival: I-75.9; II-79.0, and III-81.5%, respectively. Recurrence-free survival: I-70.8; II-75.3 and III-80.2%, respectively. No significant difference was found between tamoxifen and diethylstibestrol groups (p > 0.05). Only the difference between the control and diethylstilbestrol groups was significant. Distant metastases were detected in 112 out of 539 patients with breast tumors (TI-2N0) (20.7%), the highest rate (26.4%) being recorded in the controls who did not receive systemic adjuvant treatment. Definition of prognostic factors should be improved to help identify a group at high risk of recurrence among patients with early-stage (TIN0) breast tumors who might benefit most from adjuvant treatment.