Clinicopathological Features of Metastatic Gastric Tumors Originating From Breast Cancer: Analysis of Eleven Cases

BACKGROUND: Metastatic gastric tumor originating from breast cancer (MGTBC) is rare. Endoscopically, gastric cancer (GC)-like lesions and submucosal tumors (SMT) are the features of MGTBC. Their clinicopathological characteristics are currently uncertain. We analyzed the clinicopathological characteristics of 11 patients with MGTBC to better understand the disease progression and thereby improve early detection methods. METHODS: From 2006 to 2016, 11 patients with MGTBC diagnosed by esophagogastroduodenoscopy (EGD) were included. RESULTS: All 11 patients were women, with a median age of 57 years. Histological examination revealed six cases with solid tubular components and five cases with invasive lobular carcinoma components. Melena was the most common symptom; however, asymptomatic cases were also common. Seven and four cases had GC-like lesions and SMTs, respectively. Six of the seven cases had GC-like lesions with peritoneal metastasis, whereas none of the four SMT cases had peritoneal metastasis (P = 0.015). The median overall survival (OS) in all cases was 26 months (range, 1 - 42 months). OS in cases treated with chemotherapy after a diagnosis of gastric metastases was significantly better than that in those treated without chemotherapy (P = 0.047). One patient showed gradual transformation from an SMT-type lesion to a Borrmann type 4-like appearance. CONCLUSIONS: MGTBC is a rare occurrence; however, it should be considered when gastric tumors, especially GC-like lesions in patients with a medical history of breast cancer are found. Patients with breast cancer, especially invasive lobular carcinoma, should undergo screening EGD regularly to detect gastric metastases early and receive chemotherapy to obtain good outcomes.