[A very elderly case of advanced gastric cancer with disseminated carcinomatosis of bone marrow and multiple bone metastasis, diagnosed by extremely elevated serum alkaline phosphatase levels, and treated with low-dose S-1 to avoid disseminated intravascular coagulation].

We report an 87-year-old woman who was admitted to our hospital due to anemia and extremely elevated serum alkaline phosphatase (ALP) levels. We diagnosed advanced gastric cancer with disseminated carcinomatosis of the bone marrow and multiple bone metastasis. She was immediately treated with low-dose S-1 (50mg/body, p.o., days 1-14) and zoledronic acid hydrate (4mg/body, i.v., day 1) to avoid disseminated intravascular coagulation (DIC). After 1 course of the treatment, she could completely avoid DIC and we found the primary lesion and the metastasis had decreased. Now she is an outpatient and continues treatment without relapse for about 6 months. We consider low-dose S-1 and zoledronic acid hydrate combination therapy to be an effective strategy against advanced gastric cancer with disseminated carcinomatosis of the bone marrow and multiple bone metastasis in very elderly cases.