Metastatic spread of gastric carcinoma to the breast is rare. In previous decades, reports on this subject were minimal and primarily limited to case reports. At present, little is known on the clinicopathological features and prognosis of this condition, and breast metastasis remains a challenging clinical problem. A total of 54 cases of breast metastasis from gastric cancer were collected from databases between January 1960 and December 2016. The present study included 3 cases of gastric cancer with breast metastasis from Renji hospital and 51 additional cases from previous studies. The clinicopathological features of patients, including epidemiology, symptoms, macroscopic presentation, pathological diagnosis, imaging, treatment and overall survival time, were analyzed. The median survival time was 8.6 months. All but one of the patients were female, and the median age at diagnosis of breast metastasis was 43 years old (age range, 22-72 years). A majority of patients presented with Borrmann class III disease, signet ring cell carcinoma, T4 tumor types, lymph node involvement, initial stage IV gastric cancer, primary lesions in the gastric antrum, left breast metastasis and palpable breast nodules. The median interval between the primary gastric carcinoma diagnosis and presentation of breast metastasis was 1.25 months (range, 0-72 months). The expression of the estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2 and gross cystic disease fluid protein-15 was negative in the patients with breast metastases. In univariate analysis, age, gastric tumor size, gastric lymph node involvement and breast metastasis histology were significantly associated with overall survival (OS) time (P=0.001, 0.039, 0.034 and <0.001, respectively). Therapeutically, gastric surgery and chemotherapy were not associated with OS (P=0.959 and 0.290, respectively). In further multivariate analysis, the time between occurrence (P=0.017), age (P=0.009), histology (P=0.045) and breast metastasis localization (P=0.043) were independent indicators of OS time. Although breast metastasis from gastric cancer is rare, physicians should be vigilant when patients with a history of gastric cancer present with newly developed mammary symptoms and signs.
Keywords: breast metastasis; gastric cancer; metastatic tumor; outcome; overall survival.