Aim. To determine the frequency of local recurrence of breast cancer (BC) after performing breast-conserving surgery (BCS) during and after complex treatment, to study the risk factors for local recurrence and survival.Materials and methods. A retrospective cohort study of 675 patients with breast cancer who underwent BCS followed by remote radiotherapy was conducted. The frequency of local relapse and risk factors were studied, 3- and 5-year local-free survival. The odds ratios (OR) and 95% confidence intervals (CI) were calculated, and the Kaplan–Meyer curves were constructed.Results. Radical breast resections (RBR) were performed in 46.7% of patients, and oncoplastic breast resections (OBS) in 53.3% of patients. The most common histological type in both groups was invasive cancer with no signs of specificity: 76.9% and 84.1% – in the OBS and RBR groups, respectively. The incidence of cancer in situ was higher in the OBS group: 14.7% vs. 3.3% in the RBR group (p < 0.001), metastases in regional lymph nodes were more frequent in the RBR group: 34.3% against 20.3% in OBS (p < 0.001). According to the immunohistochemical type and degree of differentiation, the groups did not differ. For 3 years, the relapse-free survival rate was 99.7% in both groups, and for 5 years – 99.2% in the OBS group. and 99.7% in the RBR group, 6 years – 98.3% and 98.7%, respectively; no significant differences were found between the groups. There were no statistically significant differences in the frequency of relapses depending on the width of the resection edges from <1 to ≥10 mm. The risk of relapse was increased with a preserved menstrual status (OR 20.05; 95% CI 2.52–159.33), Her2/neu–positive (OR 5.11; 95% CI 1.04–25.09) and triple-negative types (OR 4.02; 95% CI 1.02–15.95), the degree of differentiation of G3 (OR 5.58; 95% CI 1.59–19.64).Conclusion. BCS is characterized by oncological safety; the rate of local relapse within 6 years is 1.5%. Risk factors for relapse include active menstrual status, highly aggressive immunohistochemical types of breast cancer, and low degree of differentiation.
Risk Factors of Local Recurrence after Breast Conserving Therapy in Invasive Breast Cancer
