Breast cancer metastasis to the stomach

Aim: This study focuses on the stomach as an unusual but not rare site of metastasis of breast cancer. Methods: We performed a literature search on gastric metastasis from breast cancer searching for reviews from 2000 to 2018 and case reports from 2013 to 2018. We found 11 reviews and 36 case reports and we compared their findings about important aspects of gastric metastasis, such as disease free survival, overall survival, symptoms, endoscopic findings, therapy, histology, and immunohistochemistry. Results: The incidence of stomach as site of metastasis of breast cancer ranges from 5% to 18%. Reviews and case reports reached similar conclusions about several of the aforementioned aspects: invasive lobular breast cancer (ILC) is mainly responsible for gastric metastases; disease free survival can vary greatly ranging from 0.5 months to 30 years; gastric metastases usually present with non-specific symptoms, even though five patients in case reports were asymptomatic; linitis plastica is the most common endoscopic finding; immunohistochemistry is essential for differentiating primary gastric cancer from metastasis; the preferred treatment is systemic therapy, but surgery is still an option in case of emergency; median overall survival of patients with gastric metastasis from breast cancer is 24 months. Conclusion: Breast metastasis to the stomach should be considered in any patient suspecting gastric neoplasm previously treated for breast carcinoma, especially if the treated carcinoma was ILC. Keywords: Gastric metastasis, breast cancer, immunohistochemistry, stomach