IntroductionGastric cancer is a cancer of the most in Japan. We report that we reviewed a double cancer with gastric cancer and the hematological malignancy. MethodsWe intended for double cancer 211 cases including hematological malignancy. We reviewed 47 double cancers including the gastric cancer. The examination factors are type of the hematological malignancy, treatment strategy, gender, the age at onset of the first cancer, interval with the second cancer. Results47 cases were 37 male, female 10, synchronous type 16 cases, asynchronous type 31 cases. The median age was 71 yrs (range 57-88yrs), the synchronous type 68.5 yrs (range 60-88 yrs), the asynchronous type was 72 yrs (range 57-87 yrs). A gender ratio was 25 vs 6 for the metachronous case. Gastric cancer precedence was 24 cases, and hematological malignancy was precedent 7cases. The gender ratio is 18 cases vs 6c ases, and 6 cases vs 1case each. As for the median age of first diagnosis, 62 yrs (range 43-84yrs), 73 yrs (range 62-75 yrs), the second cancer were 72 yrs (range 57-87 yrs), 75 yrs (range 43-84 yrs) respectively. About interval between gastric cancer and hematological malignancy, gastric cancer precedence case was 72M (ranged 17-420M), hematological malignancy precedence case was 31M (ranged 12-59M). The constitution of the hematological malignancy was malignant lymphoma 22 cases (synchronous 6 cases, metachronous 16 cases), myelodysplastic syndrome(synchronous 2 cases, metachronous 7 cases), acute myeloid leukemia 5 cases (synchronous 2 cases, metachronous 3 cases), macroglobulinemia 4 cases (synchronous 2 cases, metachronous 2 cases), multiple myeloma 4 cases (synchronous 2 cases, metachronous 2 cases), plasmacytoma 2 cases(synchronous 1case, metachronous 1 case), CLL1 case (synchronous). Clinical outcome was 16 cases survive, 31 cases died (synchronous 10 cases, metachronous 21case). The cause of death was that 1 case was gastric cancer, 29 cases were hematological malignancy and 1 case was accident. The median overall survival was 17M (range 1-116M), synchronous type 13.5M (range 4-84M), metachronous type 19M (range 1-116M). ConclusionIn the case of a double cancer including the gastric cancer, the hematological malignancy, the first cancer occurs in elderly. Diagnosis of gastric cancer within 3 years were 5 cases out of 7 cases. The important point is that 3 years are required for careful observation at the time of hematological malignancy diagnosis. It is nessessary to discover gastric cancer by upper digestive endoscopy at the early stage. So it could be a lot of treatment options for hematological malignancy. We think that a prognosis is improved.