Predictive Factors and Prognostic Value of Pathologic Complete Response of Internal Mammary Lymph Nodes in Breast Cancer After Neoadjuvant Chemotherapy

Objective To explore the prognostic factors of the pathological complete response of internal mammary lymph node (ipCR) after neoadjuvant chemotherapy and its effect on breast cancer prognosis.

Methods We retrospectively analyzed the clinical data of 70 patients with primary breast cancer with internal mammary lymph node metastasis who received neoadjuvant chemotherapy. Patients were divided into the ipCR group and non-ipCR group based on their postoperative pathology. χ² test, Fisher, and Logistic regression were used for univariate and multivariate analysis. Meanwhile, the Kaplan-Meier curve and Cox regression were used for prognostic analysis.

Results Of 70 patients, 31 obtained ipCR (44.3%). Univariate analysis showed that the expression levels of apCR, HR, and HER2 status were related to ipCR (P < 0.05). Multivariate analysis showed that age, apCR, and HER2 status were independent predictors of ipCR (P < 0.05). The average DFS of ipCR group was better than non-ipCR group (96.0 vs. 67.1 months, P < 0.05). The risk of recurrence and metastasis was 87% lower in the ipCR group than in the non-ipCR group (HR=0.13, 95%CI: 0.04-0.44, P < 0.01). ipCR, Ki67 expression level, and breast pCR (bpCR) were independent factors affecting patients' prognosis.

Conclusion There is a correlation between clinico pathological factors and ipCR after neoadjuvant chemotherapy. ipCR can be used to predict the prognosis of patients with internal mammary lymph node metastasis.