Prognostic factors for the node-negative breast cancers

Objective

The proportion of node-negative breast cancer patients has been increasing with improvement of diagnostic modalities and early detection. However, there is a 20–30% recurrence in node-negative breast cancer. To identify the prognostic factors for node-negative breast cancers, we studied the impact of many clinico-pathologic parameters on the outcome of the node-negative breast cancer patients.

Methods

The data of 1,110 node-negative breast cancer patients who underwent curative surgery at the Severance Hospital, Yonsei University College of Medicine, were reviewed. The impact of many clinico-pathological parameters on the outcome was investigated. Univariate survival curves for disease-free survival and death were estimated using the Kaplan–Meier method: group differences in survival time were tested by the log-rank test. Multivariate Cox regression analysis was performed to compare and identify independent prognostic factors.

Results

The mean age was 47.2 years. The median follow-up was 88 months. Recurrence occurred in 161 patients; 64 patients with locoregional recurrences, 129 with systemic recurrences, and 32 with both. The 5-year overall survival rate was 93.3%. The rate of locoregional recurrence for a 10-year period was significantly lower in the mastectomy group compared with those in the breast conservation therapy group (94.7% versus 79.6%, P = 0.000). No other prognostic factors except age affected locoregional recurrence. There was less systemic recurrence in patients with age greater than 35, with histologic grade I, and with intraductal components greater than 20%. Thus, the 10-year distant relapse-free survival rates were 87.4% versus 79.8% (P = 0.039), 93.5% versus 85.5% (P = 0.024), and 94.4% versus 82.0% (P = 0.007), respectively. There was no statistical significance in the other prognostic factors that influence systemic recurrence.

Conclusion

Patient age, histologic grade, and presence of intraductal component were identified as independent prognostic factors in node-negative breast cancer patients.