Characteristics of synchronous cancers in gastric cancer patients.

PURPOSE: The primary objective of the current study was to investigate the characteristics of synchronous cancers in gastric cancer patients.
MATERIALS AND METHODS: We analyzed the 2,237 patients who were diagnosed between December 2000 and December 2003 with gastric cancer and synchronous cancers of organs other than the stomach.
RESULTS: 73 (3.3%) of a total of 2,237 gastric cancer patients had synchronous primary cancers. Among these 73 patients, 71 had one synchronous cancer, and two patients had double synchronous cancers. Colorectal cancer (26 patients, 34.7%) was the most frequently encountered synchronous cancer, followed by cancer of the lung (16 patients, 21.3%), esophagus (13 patients, 17.2%), and liver (8 patients, 10.7%). Synchronous cancers were detected with increased frequency in the elderly, in the patients with multiple gastric cancers, in the patients with differentiated gastric cancer, and in the patients with early gastric cancer, as determined on univariate analysis, but the differentiation of gastric cancers was the only risk factor for synchronous cancers on the multivariate analysis.
CONCLUSIONS: The differentiation of gastric cancer cells may be a risk factor for synchronous cancers in gastric cancer patients. Careful surveillance by the physician for synchronous cancer is warranted for the patients suffering from gastric cancer.