Abstract
The aim of this study was to evaluate clinical implication of the presence of other primary cancer (OPC) incases of colorectal cancer patients. A total 2, 141 cases were enrolled in this study. Of the total 387 (18.1%) hadOPC. There were 108 cases with synchronous and 288 cases with metachronous multiple cancers. The colorectal cancer cases with OPC had a significantly poorer prognosis as compared with those without OPC. Andthe rate of death for OPC was higher in patients with postoperative metachronous OPC than in those without.The major sites of OPC were the stomach (43.8%) and lung (15.3%) in males and breast (32.4%) and uterus (25.5%) in females. Multiple colorectal cancers appeared to be a risk factor for OPC. Postoperative metachronous gastric cancer was frequently found five to ten years after the operation and lung cancer within fiveyears after the operation. We must carefully monitor patients for the development of OPC, in particular, gastric cancer and lung cancer, especially in patients with multiple colorectal cancers.
