A Case of Simultaneous Double Cancer with Gastric Metastasis of Breast Cancer and Lung Cancer

A 60s female with complaint of epigastric discomfort revealed 0-Ⅱb lesion in gastric fornix on upper gastrointestinal endoscopy and exhibited signet-ring cell carcinoma on histopathologic examination of biopsy specimens. A thoracoabdominal CT scan suggested tumors in right breast and left lung, and biopsy revealed invasive lobular carcinoma and primary lung adenocarcinoma, respectively. As results of multidisciplinary discussion of the treatment strategy for triple cancers, it was decided to perform robotic proximal gastrectomy, D1+ lymph node dissection, and esophagogastrostomy. The gastric lesion was diagnosed as gastric metastasis of breast cancer(T2N1M1, Stage Ⅳ)because immunohistochemical staining findings showed ER(+), GCDFP-15(+), and GATA-3(+). Two months later, she underwent the left upper lobectomy, and was diagnosed with lung acinar adenocarcinoma(pT2N0M0, pStage ⅠB). Six months after gastrectomy, she is currently on hormone therapy with aromatase inhibitors for breast cancer.