Review of 35 cases highlights diagnostic challenges in gastric metastasis from invasive lobular breast cancer

This publication is a case report and literature review focusing on gastric metastasis originating from breast cancer, specifically invasive lobular carcinoma. The scope encompasses a systematic review of 35 cases reported between 2019 and 2024. The authors synthesize findings regarding histology, symptoms, and immunohistochemical markers to inform clinical suspicion in this rare presentation.

The review identifies invasive lobular carcinoma as the predominant histology, present in 57.14% of the analyzed cases. Abdominal pain was the most frequent symptom, reported in 54.29% of patients. Immunohistochemical profiling revealed GATA3 positivity in 71.43% of cases. Hormone receptor expression showed significant heterogeneity; ER expression was detected in 80% of primary tumors but only in 30% of gastric metastases, while PR expression was negative in the metastatic sites.

The authors note the necessity for heightened clinical suspicion in breast cancer patients presenting with upper gastrointestinal symptoms. They advocate for a structured diagnostic pathway centered on endoscopic deep biopsy and comprehensive immunohistochemical profiling to distinguish primary gastric cancer from metastasis. Re-biopsy is recommended to assess phenotypic evolution, as receptor status may change between primary and metastatic sites. Surgical intervention should generally be reserved for palliation of complications or selected cases of oligometastatic disease.

Safety data, including adverse events and tolerability, were not reported in this review. The findings are based on a small sample of 35 cases, which limits the generalizability of the results. Clinicians should interpret these qualitative conclusions with caution, recognizing the observational nature of the evidence.