A prognostic model based on nodal status and Ki-67 predicts the risk of recurrence and death in breast cancer patients with residual disease after preoperative chemotherapy

Methods: Two hundred and twenty-one stage II-III breast cancer patients were included. The following parameters were evaluated at baseline and on surgical specimens after PCT: estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), Ki-67, p53, human epidermal growth factor receptor (EGFR), vascular endothelial growth factor receptor 2 (VEGFR2), and apoptosis. Results: A pathological complete response was observed in 8.8% of the patients. PCT induced a significant reduction in the expression of ER, PgR, Ki-67, and apoptosis. As by multivariable model, Ki-67 >= 15% and nodal positivity after preoperative chemotherapy (PCT) were significant predictors of worse disease-free survival [hazard ratio (HR) 3.79, P < 0.0001 and HR 2.31, P = 0.037, respectively]. Ki-67 >= 15% after PCT was also a significant predictor of overall survival (HR 3.75, P = 0.013). On the basis of these two parameters, patients were classified into three groups: (i) low risk (negative nodes and Ki-67 < 15%), (ii) intermediate risk (nodal positivity or Ki-67 >= 15%), and (iii) high risk (nodal positivity and Ki-67 >= 15%). As compared with the low-risk group, the HRs for recurrence were 3.1 and 9.3 for the intermediate- and high-risk group, respectively (P = 0.0001); the HRs for death were 2.4 and 6.5 for the intermediate- and high-risk group, respectively (P = 0.042). Conclusions: Ki-67 and nodal status have been used to generate a simple and easily reproducible prognostic model, able to discriminate patients with worse prognosis among the heterogeneous group of women with residual disease after PCT.