Clinicopathological characteristics and prognostic factors in invasive micropapillary carcinoma of the breast.

Introduction: Invasive micropapillary carcinoma (IMPC) treatment only relies on the standard treatment of nonspecific invasive breast cancer (NSIBC), and it remains controversial whether the survival of patients improves. Therefore, this study aimed to analyze the clinicopathological features of IMPC and to investigate the factors affecting its prognosis. Material and methods: This retrospective cohort study included 104 IMPC patients who met the study's inclusion criteria out of a total of 4,532 patients with invasive breast cancer between January 2015 and December 2019. A contemporaneous cohort of 230 patients with non-specific invasive breast cancer (NSIBC) who underwent surgery was identified and matched using propensity scores. Results: The survival rate for patients with IMPC ranged from 1.12% to 7.03%. Statistically significant differences were observed in the proportion of endocrine treatment, lymphatic invasion, estrogen receptor (ER)-positive rate, molecular subtypes, molecular typing, and 5-year loco-regional recurrence-free survival (LRRFS) between the two cohorts (p < 0.05). The univariate analysis showed that T stage, N stage, lymphatic invasion, vascular invasion, ER-positive rate, and progesterone receptor (PR)-negative rate were all prognosis risk factors (p < 0.05) for IMPC. Furthermore, the multivariate analysis indicated that lymphatic invasion and N stage were independent prognostic factors (p < 0.05). Conclusions: The incidence of micropapillary IMPC, among other pathological subtypes, is steadily increasing. ER-positive and PR-positive rates, as well as luminal subtypes, are frequent, with a concurrent increase in the 5-year locoregional recurrence rate. It would be interesting to compare the effect following these therapeutic modifications in larger cohorts in future studies.

The Role of Ki-67 in HR+/HER2- Breast Cancer: A Real-World Study of 956 Patients.

Objective: This study determined the cut-off value of Ki-67 expression and discussed the interaction between Ki-67 and histological grade, further explored the prognostic role of Ki-67 in hormone receptor-positive and human epidermal growth factor receptor 2 negative (HR+/HER2-) breast cancer;. Materials and Methods: We assessed the Ki-67 expression of 956 patients with HR+/HER2 breast cancer diagnosed in the General Hospital of Ningxia Medical University from 2015 to 2019 by immunohistochemistry (IHC), The disease-free survival (DFS) was defined as the time from postoperative to the first local recurrence, distant metastasis or death of the disease. The follow-up by means of inpatient or outpatient medical records and telephone. Results: 22.5% was used as the cut-off for low/high Ki-67 expression in HR+/HER2- breast cancer. Compared with the value of 14%, which is commonly used in clinic at present, the consistency of the two values is moderate (Kappa = 0.484, P<0.001). The expression of Ki-67 was increased with the grade. (Median: G1:10%; G2:20%; G3:40%. Mean: G1:13%; G2:23%; G3:39%, P <0.001). Survival analysis was based on all patients for a median of 51 months (24-89 months), 63 cases had recurrence or metastasis during the follow-up, which 21 cases had low expression of Ki-67 and 42 cases had high expression. The patients with Ki-67 ≥ 22.5% had a 2.969 higher risk of early recurrence and metastasis than the patients with Ki-67 < 22.5%. There were 4 cases of local recurrence, 7 cases of regional lymph node metastasis, and 52 cases of distant metastasis in all patients, the common distant metastases were bone, liver, and lung, and rare metastases were adrenal gland, bone marrow, and pericardium. Conclusion: In HR+/HER2- breast cancer, patients with Ki-67 > 22.5% have a worse prognosis and are more likely to have early recurrence and metastasis.

miR-3646 promotes cell proliferation, migration, and invasion via regulating G2/M transition in human breast cancer cells.

MicroRNAs (miRNAs) are small non-coding RNAs that are often located in genomic breakpoint regions and play a critical role in regulating a variety of the cellular processes in human cancer. miR-3646 has been reported to take part in tumorigenic progression in breast and bladder cancer, but its potential functions and exact mechanistic roles in breast cancer are still unclear. The objective of this study was to investigate the role of miR-3646 in breast cancer growth and metastasis using both bioinformatic and experimental approaches. Before starting the bench work, we conducted a bioinformatic study to predict the target genes regulated by miR-3646 using a panel of different algorithms. The results showed that miR-3646 might regulate a large number of genes that are related to cell growth, proliferation, metabolis, transport, and apoptosis and some were cancer-related genes. We found that the expression level of miR-3646 was significantly upregulated in breast cancer cells and tissues compared with normal breast cells and no tumor tissues. Subsequently, the MTT and colony formation assay results showed that up-regulation of miR-3646 promoted the cell viability and proliferation. Our results also showed that down-regulation of miR-3646 arrested the cells in G2/M phase in MCF7 and MDA-MB-231 cells which was accompanied by the down-regulation of CDK1/CDC2 and cyclin B1 and upregulation of p21Waf1/Cip1, p27 Kip1, and p53, suggesting that down-regulation of miR-3646 induces G2/M arrest through activation of the p53/p21/CDC2/cyclin B1 pathway. In addition, overexpression of miR-3646 promoted migration and invasion of MCF7 and MDA-MB-231 cells. Taken together, miR-3646 is a potential oncogene in breast cancer and it may represent a new niomarker in the diagnosis and prediction of prognosis and therapeutic response.