OBJECTIVETo study the incidence, clinicopathological characteristics, diagnosis, treatment, and prognosis of synchronous or metachronous primary cancers in patients with gastric cancer.

METHODSClinical data of 4426 patients with gastric cancer in our hospital from 1996 to 2007 were reviewed.

RESULTSSeventy-four (1.7%) patients had synchronous or metachronous primary cancer of other organ, of whom 10 were synchronous and 64 were metachronous. Colorectal cancer was the most common type of primary cancer in other organs (43.8%), followed by breast cancer (16.3%). The mean time interval between gastric cancer and metachronous primary cancer was 82.2 (3-354) months. The mean age at the diagnosis of gastric cancer was 61.2 (33-84) years. The 5-year overall survival rate was 42.3%. The 5-year survival rates in patients with synchronous cancer, pre-metachronous cancer or post-metachronous cancer were 15.2%, 42.9% and 51.3%, respectively. Causes of death were primary cancers of other organ in 11 patients, gastric cancer in 24, and renal failure in 1 patient.

CONCLUSIONSPrimary cancer of other organ should be considered in the management of gastric cancer. Aggressive treatment should be used for the second primary cancer. Gastric cancer is the main cause of death in these patients.