Metastatic gastric cancer from breast carcinoma: A report of 78 cases

The metastatic spread of breast carcinoma to the stomach is rare. There are a small number of previous studies that report metastases from the breast to the stomach and these provide limited information regarding this infrequent event. Consequently, the clinicopathological features, clinical outcomes and the optimal treatment for these patients remain to be elucidated. In the present study, 78 cases of gastric metastases from breast cancer, including the current case, were identified from previous studies between 1960 and 2015. The clinicopathological features of primary breast tumors and metastatic gastric lesions, including initial stage, tumor size, hormone receptor status, treatment modalities and overall survival (OS) rate, were analyzed. The patients were all female and the median age at the time of gastric metastasis diagnosis was 59 years old (range, 38-86 years). The majority of the patients initially presented with stage II breast cancer (35.9%) and abdominal pain was the most common symptom of gastric metastases (75.6%). A total of 51/78 patients (65.4%) were identified to have a history of invasive lobular breast carcinoma and the majority of gastric tumors were positive for hormonal receptors and human epidermal growth factor receptor 2 (HER-2) negative (estrogen receptor, 94.0%; progesterone receptor, 68.3%; HER-2, 5.9%). Furthermore, in the univariate analysis, multiple organs involved prior to or at the time of gastric metastases were diagnosed and multiple gastric lesions and peritoneal carcinomatosis were significantly correlated with OS. Additionally, salvage hormonal therapy, but not surgery or chemotherapy, significantly extended OS. However, in the multivariate analysis, metastasis prior to stomach involvement was the only independent indicator of poor OS. In conclusion, physicians must be vigilant when patients with breast cancer history present with gastrointestinal symptoms, despite gastric metastasis from breast cancer being rare. An appropriate systemic therapeutic strategy that includes hormonal therapy may be beneficial for this group of patients.