Evaluation of Lymph Node Metastasis in Invasive Micropapillary Breast Carcinoma and Other Its Related Variables

Background: The rate of lymph node metastasis in patients with invasive micropapillary carcinoma (IMPC) could be considered a critical prognostic factor whose measurement may enhance therapeutic outcomes in these patients. Objectives: The current study aims at determining the rate of lymph node involvement in IMPC patients and comparing it with that of invasive ductal carcinoma, not otherwise specified (IDC-NOS) patients. Methods: In this case-control study, a total of 124 participated, including 61 patients with IMPC and 63 patients with IDC-NOS. The rate of lymph node metastasis and its possible connection with the patient's age, tumor size, grade and focality, lymphovascular invasion, and proportion of micropapillary component were determined in patients with IMPC and compared to that of IDC-NOS patients. Results: Lymph node involvement was detected in 80.3% of patients with IMPC, which is significantly higher compared to patients with IDC-NOS. No significant correlation was found between lymph node metastasis and the patients' age, tumor size, and focality in both IMPC and IDC-NOS groups. Furthermore, no significant relationship was observed between lymph node metastasis and tumor grade in IMPC, while metastasis to lymph nodes was directly correlated with higher tumor grades of NOS type. Moreover, in both types of cancer, lymph node metastasis was significantly associated with lymphovascular invasion. In patients with IMPC, no statistically significant relevance was observed between lymph node metastasis and the percentage of micropapillary components. Conclusions: According to the results of this study, patients with IMPC had a significantly higher rate of lymph node involvement compared to IDC-NOS. Hence, the rate of lymph node involvement could be used as a prognostic factor in these patients.