Long-term outcomes and predictors of recurrence in node-negative early stage breast cancer patients.

Background: We evaluated the outcomes, and risk factors for recurrence in patients with early stage node-negative breast cancer in this study.

Method: Retrospective data analysis was done on patient treatment records from 1988 to 2018. The patient's demographic, clinical, pathological, and therapeutic characteristics were noted. To evaluate survival analysis and predictors of recurrence, we employed Kaplan-Meier analysis with the log-rank test.

Results: A total of 357 patients in all were enrolled in the research. At the time of diagnosis, the median age was 50 (with a range of 18-81). A total of 85.5% of patients had undergone a lumpectomy, while 14.5% had a mastectomy. 78.7% of patients had sentinel lymph node biopsy, and 21.3% had axillary lymph node dissection. In addition, the patients received adjuvant radiotherapy (88.7%), adjuvant endocrine therapy (82.1%), and adjuvant chemotherapy (48.5%). Recurrence of the tumor occurred in 31 (8.7%) patients (local recurrence 45.2% and metastatic disease 54.8%). Ten- and twenty-year recurrence-free survival rates were 92% and 77%. 19 (5.3%) patients had also developed contralateral breast cancer. Ten-year survival rates were 91.6%, and 20-year survival rates were 76.6%, respectively. Aged over 65 years (p = 0.004), necrosis (p = 0.002), mitosis (p = 0.003), and nuclear pleomorphism (p = 0.049) were found as statistically significant factors for recurrence in univariate analysis. In the ROC analysis, the largest size of the tumor (over 1.45 cm, p = 0.07) remained outside the statistical significance limit in terms of recurrence.

Conclusions: Thirty-year outcomes in individuals with early stage, node-negative breast cancer were shown in this study. We found that the recurrence ratios between 10 and 20 years were more frequent than the first 10 years during the follow-up. Despite the small number of patients who experienced a recurrence, we demonstrated that, in univariate analysis, being older than 65 and having some pathological characteristics (nuclear pleomorphism, mitosis, and necrosis) were statistically significant factors for disease recurrence.