Gastric phenotype signet-ring cell carcinoma of the stomach with multiple bone metastases effectively treated with sequential methotrexate and 5-fluorouracil

A 63-year-old woman presented with an abnormal serum alkaline phosphatase (ALP) level. Computed tomography (CT) scan of the abdomen and pelvis and radioisotope (RI) examination led to a strong suspicion of systemic bone metastatic tumors, although the origin was not known. Biopsies from bone metastatic lesions in the left ilium were performed under CT scan, and signet-ring cell carcinoma cells were detected pathologically. Also, a 0-IIc-like lesion was observed endoscopically in the stomach, and signet-ring cell carcinoma cells were also detected histologically. The patient's platelet (Plt) levels were reduced and slight bleeding from the gingiva was detected when she brushed her teeth. Both the stomach and the bone metastatic lesions exhibited a gastric phenotype (G type) phenotypically. From these findings, we diagnosed the patient as having advanced (inoperable) stomach cancer with multiple bone metastases; she also exhibited disseminated intravascular coagulation (DIC). We treated her with sequential methotrexate and 5-fluorouracil (sequential MTX/5-FU) therapy after obtaining her informed consent. After six cycles of the chemotherapy, the abnormal ALP and Plt levels were alleviated. At present, she is receiving weekly sequential MTX/5-FU therapy at the outpatient oncology unit; she has been receiving the therapy for about 7 months since the detection of the bone metastases and has had a total of 17 cycles. In conclusion, sequential MTX/5-FU therapy was effective for a patient with G-type signet-ring cell carcinoma of the stomach with bone metastases, suggesting that the phenotypic classification may be one of the useful markers for prediction of the effectiveness of chemotherapy in patients with inoperable advanced stomach cancer.