Advanced hormone receptor-positive/human epidermal growth factor receptor 2-positive invasive ductal carcinoma with cecal metastasis: A case report.

The incidence of gastrointestinal metastases from breast cancer (BC) is low. We report a special case of Luminal B (Hormone Receptor positive [HR+]/Human Epidermal Growth Factor receptor 2-positive [HER-2+]) BC. The patient presented with asymptomatic brain metastases two years after radical surgery for modified breast cancer and developed right lower abdominal pain during relief therapy. Electronic gastroenteroscopy revealed inflammatory changes in the cecal mucosa. These changes were confirmed on pathology to be cecal metastasis from BC. The patient's condition was stabilised after treatment with an antibody-drug conjugate (ADC). For patients with BC who develop appendicitis-like symptoms after treatment for invasive ductal carcinoma of the breast, clinicians should be fully aware that the possibility of cecal metastasis needs to be considered, despite the very low probability of occurrence.

Circular RNA hsa_circ_0001982 Promotes Breast Cancer Cell Carcinogenesis Through Decreasing miR-143.

Circular RNAs (circRNAs) are a type of noncoding RNAs generated from back-splicing, which have been verified to mediate multiple tumorigenesis. With the development of high-throughput sequencing, massive circRNAs are discovered in tumorous tissue. However, the potential physiological effect of circRNAs in breast cancer is still unknown. The purpose of this study is to investigate the expression profile of circRNA in breast cancer tissue and explore the in-depth regulatory mechanism in breast cancer tumorigenesis. In the present study, we screened the circRNA expression profiles in breast cancer tissue using circRNA microarray analysis. Totally 1705 circRNAs were identified to be significantly aberrant. Among these dysregulated circRNAs, hsa_circ_0001982 was markedly overexpressed in breast cancer tissue and cell lines. Bioinformatics analysis predicted that miR-143 acted as target of hsa_circ_0001982, which was confirmed by Dual-luciferase reporter assay. Loss-of-function and rescue experiments revealed that hsa_circ_0001982 knockdown suppressed breast cancer cell proliferation and invasion and induced apoptosis by targeting miR-143. In summary, our study preliminarily investigates the circRNA expression in breast cancer tissue and explores the role of competing endogenous RNA (ceRNA) mechanism in the progression, providing a novel insight for breast cancer tumorigenesis.