Abstract
Twenty cases of primary colorectal cancer associated with gastric cancer synchronously or metachronously were operated in our hospital from 1954 to 1982. The average age of these patients was 62.6 years old and 9 cases were male. In the period from 1974 to 1982, a series of 373 patients with colorectal cancer were treated, while 777 patients with gastric cancer were treated. The incidence of colorectal cancer associated with gastric cancer was 4.0% in colorectal series, and 1.9% in gastric series respectively.
Seven of 20 patients had synchronous cancer. In 3 cases, colorectal cancer was found first and gastric cancer was diagnosed later by preoperative examination. On the contrary, in 3 cases of gastric cancer, colorectal cancer was found at the time of operation.
Thirteen of 20 patients had metachronous cancer. Seven patients were treated due to colorectal cancer initially, 6 patients were treated due to gastric cancer initially. The average interval between the first and the second primary cancer was 7 years and 5 months from the first colorectal cancer to the second gastric cancer, and 3 years from gastric can-cer to colorectal cancer. About half of the gastric cancer was early gastric cancer while in colorectal cancer, there was only one case of early cancer.
